advanced_1000_h1=Advanced
advanced_1001_a=\ Result Sets
advanced_1002_a=\ Large Objects
advanced_1003_a=\ Linked Tables
advanced_1004_a=\ Recursive Queries
advanced_1005_a=\ Updatable Views
advanced_1006_a=\ Transaction Isolation
advanced_1007_a=\ Multi-Version Concurrency Control (MVCC)
advanced_1008_a=\ Clustering / High Availability
advanced_1009_a=\ Two Phase Commit
advanced_1010_a=\ Compatibility
advanced_1011_a=\ Standards Compliance
advanced_1012_a=\ Run as Windows Service
advanced_1013_a=\ ODBC Driver
advanced_1014_a=\ Using H2 in Microsoft .NET
advanced_1015_a=\ ACID
advanced_1016_a=\ Durability Problems
advanced_1017_a=\ Using the Recover Tool
advanced_1018_a=\ File Locking Protocols
advanced_1019_a=\ Using Passwords
advanced_1020_a=\ Password Hash
advanced_1021_a=\ Protection against SQL Injection
advanced_1022_a=\ Protection against Remote Access
advanced_1023_a=\ Restricting Class Loading and Usage
advanced_1024_a=\ Security Protocols
advanced_1025_a=\ SSL/TLS Connections
advanced_1026_a=\ Universally Unique Identifiers (UUID)
advanced_1027_a=\ Settings Read from System Properties
advanced_1028_a=\ Setting the Server Bind Address
advanced_1029_a=\ Pluggable File System
advanced_1030_a=\ Split File System
advanced_1031_a=\ Database Upgrade
advanced_1032_a=\ Java Objects Serialization
advanced_1033_a=\ Limits and Limitations
advanced_1034_a=\ Glossary and Links
advanced_1035_h2=Result Sets
advanced_1036_h3=Statements that Return a Result Set
advanced_1037_p=\ The following statements return a result set\: <code>SELECT, EXPLAIN, CALL, SCRIPT, SHOW, HELP</code>. All other statements return an update count. 
advanced_1038_h3=Limiting the Number of Rows
advanced_1039_p=\ Before the result is returned to the application, all rows are read by the database. Server side cursors are not supported currently. If only the first few rows are interesting for the application, then the result set size should be limited to improve the performance. This can be done using <code>LIMIT</code> in a query (example\: <code>SELECT * FROM TEST LIMIT 100</code>), or by using <code>Statement.setMaxRows(max)</code>. 
advanced_1040_h3=Large Result Sets and External Sorting
advanced_1041_p=\ For large result set, the result is buffered to disk. The threshold can be defined using the statement <code>SET MAX_MEMORY_ROWS</code>. If <code>ORDER BY</code> is used, the sorting is done using an external sort algorithm. In this case, each block of rows is sorted using quick sort, then written to disk; when reading the data, the blocks are merged together. 
advanced_1042_h2=Large Objects
advanced_1043_h3=Storing and Reading Large Objects
advanced_1044_p=\ If it is possible that the objects don't fit into memory, then the data type CLOB (for textual data) or BLOB (for binary data) should be used. For these data types, the objects are not fully read into memory, by using streams. To store a BLOB, use <code>PreparedStatement.setBinaryStream</code>. To store a CLOB, use <code>PreparedStatement.setCharacterStream</code>. To read a BLOB, use <code>ResultSet.getBinaryStream</code>, and to read a CLOB, use <code>ResultSet.getCharacterStream</code>. When using the client/server mode, large BLOB and CLOB data is stored in a temporary file on the client side. 
advanced_1045_h3=When to use CLOB/BLOB
advanced_1046_p=\ By default, this database stores large LOB (CLOB and BLOB) objects separate from the main table data. Small LOB objects are stored in-place, the threshold can be set using <a href\="grammar.html\#set_max_length_inplace_lob" class\="notranslate" >MAX_LENGTH_INPLACE_LOB</a>, but there is still an overhead to use CLOB/BLOB. Because of this, BLOB and CLOB should never be used for columns with a maximum size below about 200 bytes. The best threshold depends on the use case; reading in-place objects is faster than reading from separate files, but slows down the performance of operations that don't involve this column. 
advanced_1047_h3=Large Object Compression
advanced_1048_p=\ CLOB and BLOB values can be compressed by using <a href\="grammar.html\#set_compress_lob" class\="notranslate" >SET COMPRESS_LOB</a>. The LZF algorithm is faster but needs more disk space. By default compression is disabled, which usually speeds up write operations. If you store many large compressible values such as XML, HTML, text, and uncompressed binary files, then compressing can save a lot of disk space (sometimes more than 50%), and read operations may even be faster. 
advanced_1049_h2=Linked Tables
advanced_1050_p=\ This database supports linked tables, which means tables that don't exist in the current database but are just links to another database. To create such a link, use the <code>CREATE LINKED TABLE</code> statement\: 
advanced_1051_p=\ You can then access the table in the usual way. Whenever the linked table is accessed, the database issues specific queries over JDBC. Using the example above, if you issue the query <code>SELECT * FROM LINK WHERE ID\=1</code>, then the following query is run against the PostgreSQL database\: <code>SELECT * FROM TEST WHERE ID\=?</code>. The same happens for insert and update statements. Only simple statements are executed against the target database, that means no joins. Prepared statements are used where possible. 
advanced_1052_p=\ To view the statements that are executed against the target table, set the trace level to 3. 
advanced_1053_p=\ If multiple linked tables point to the same database (using the same database URL), the connection is shared. To disable this, set the system property <code>h2.shareLinkedConnections\=false</code>. 
advanced_1054_p=\ The statement <a href\="grammar.html\#create_linked_table" class\="notranslate" >CREATE LINKED TABLE</a> supports an optional schema name parameter. 
advanced_1055_p=\ The following are not supported because they may result in a deadlock\: creating a linked table to the same database, and creating a linked table to another database using the server mode if the other database is open in the same server (use the embedded mode instead). 
advanced_1056_p=\ Data types that are not supported in H2 are also not supported for linked tables, for example unsigned data types if the value is outside the range of the signed type. In such cases, the columns needs to be cast to a supported type. 
advanced_1057_h2=Updatable Views
advanced_1058_p=\ By default, views are not updatable. To make a view updatable, use an "instead of" trigger as follows\: 
advanced_1059_p=\ Update the base table(s) within the trigger as required. For details, see the sample application <code>org.h2.samples.UpdatableView</code>. 
advanced_1060_h2=Transaction Isolation
advanced_1061_p=\ Transaction isolation is provided for all data manipulation language (DML) statements. Most data definition language (DDL) statements commit the current transaction. See the <a href\="grammar.html">Grammar</a> for details. 
advanced_1062_p=\ This database supports the following transaction isolation levels\: 
advanced_1063_b=Read Committed
advanced_1064_li=\ This is the default level. Read locks are released immediately after executing the statement, but write locks are kept until the transaction commits. Higher concurrency is possible when using this level.
advanced_1065_li=\ To enable, execute the SQL statement <code>SET LOCK_MODE 3</code>
advanced_1066_li=\ or append <code>;LOCK_MODE\=3</code> to the database URL\: <code>jdbc\:h2\:~/test;LOCK_MODE\=3</code> 
advanced_1067_b=Serializable
advanced_1068_li=\ Both read locks and write locks are kept until the transaction commits. To enable, execute the SQL statement <code>SET LOCK_MODE 1</code>
advanced_1069_li=\ or append <code>;LOCK_MODE\=1</code> to the database URL\: <code>jdbc\:h2\:~/test;LOCK_MODE\=1</code> 
advanced_1070_b=Read Uncommitted
advanced_1071_li=\ This level means that transaction isolation is disabled.
advanced_1072_li=\ To enable, execute the SQL statement <code>SET LOCK_MODE 0</code>
advanced_1073_li=\ or append <code>;LOCK_MODE\=0</code> to the database URL\: <code>jdbc\:h2\:~/test;LOCK_MODE\=0</code> 
advanced_1074_p=\ When using the isolation level 'serializable', dirty reads, non-repeatable reads, and phantom reads are prohibited. 
advanced_1075_b=Dirty Reads
advanced_1076_li=\ Means a connection can read uncommitted changes made by another connection.
advanced_1077_li=\ Possible with\: read uncommitted 
advanced_1078_b=Non-Repeatable Reads
advanced_1079_li=\ A connection reads a row, another connection changes a row and commits, and the first connection re-reads the same row and gets the new result.
advanced_1080_li=\ Possible with\: read uncommitted, read committed 
advanced_1081_b=Phantom Reads
advanced_1082_li=\ A connection reads a set of rows using a condition, another connection inserts a row that falls in this condition and commits, then the first connection re-reads using the same condition and gets the new row.
advanced_1083_li=\ Possible with\: read uncommitted, read committed 
advanced_1084_h3=Table Level Locking
advanced_1085_p=\ The database allows multiple concurrent connections to the same database. To make sure all connections only see consistent data, table level locking is used by default. This mechanism does not allow high concurrency, but is very fast. Shared locks and exclusive locks are supported. Before reading from a table, the database tries to add a shared lock to the table (this is only possible if there is no exclusive lock on the object by another connection). If the shared lock is added successfully, the table can be read. It is allowed that other connections also have a shared lock on the same object. If a connection wants to write to a table (update or delete a row), an exclusive lock is required. To get the exclusive lock, other connection must not have any locks on the object. After the connection commits, all locks are released. This database keeps all locks in memory. When a lock is released, and multiple connections are waiting for it, one of them is picked at random. 
advanced_1086_h3=Lock Timeout
advanced_1087_p=\ If a connection cannot get a lock on an object, the connection waits for some amount of time (the lock timeout). During this time, hopefully the connection holding the lock commits and it is then possible to get the lock. If this is not possible because the other connection does not release the lock for some time, the unsuccessful connection will get a lock timeout exception. The lock timeout can be set individually for each connection. 
advanced_1088_h2=Multi-Version Concurrency Control (MVCC)
advanced_1089_p=\ The MVCC feature allows higher concurrency than using (table level or row level) locks. When using MVCC in this database, delete, insert and update operations will only issue a shared lock on the table. An exclusive lock is still used when adding or removing columns, when dropping the table, and when using <code>SELECT ... FOR UPDATE</code>. Connections only 'see' committed data, and own changes. That means, if connection A updates a row but doesn't commit this change yet, connection B will see the old value. Only when the change is committed, the new value is visible by other connections (read committed). If multiple connections concurrently try to update the same row, the database waits until it can apply the change, but at most until the lock timeout expires. 
advanced_1090_p=\ To use the MVCC feature, append <code>;MVCC\=TRUE</code> to the database URL\: 
advanced_1091_p=\ MVCC is disabled by default. The MVCC feature is not fully tested yet. The limitations of the MVCC mode are\: it can not be used at the same time as <code>MULTI_THREADED\=TRUE</code>; the complete undo log (the list of uncommitted changes) must fit in memory when using multi-version concurrency. The setting <code>MAX_MEMORY_UNDO</code> has no effect. It is not possible to enable or disable this setting while the database is already open. The setting must be specified in the first connection (the one that opens the database). 
advanced_1092_p=\ If MVCC is enabled, changing the lock mode (<code>LOCK_MODE</code>) has no effect. 
advanced_1093_h2=Clustering / High Availability
advanced_1094_p=\ This database supports a simple clustering / high availability mechanism. The architecture is\: two database servers run on two different computers, and on both computers is a copy of the same database. If both servers run, each database operation is executed on both computers. If one server fails (power, hardware or network failure), the other server can still continue to work. From this point on, the operations will be executed only on one server until the other server is back up. 
advanced_1095_p=\ Clustering can only be used in the server mode (the embedded mode does not support clustering). The cluster can be re-created using the <code>CreateCluster</code> tool without stopping the remaining server. Applications that are still connected are automatically disconnected, however when appending <code>;AUTO_RECONNECT\=TRUE</code>, they will recover from that. 
advanced_1096_p=\ To initialize the cluster, use the following steps\: 
advanced_1097_li=Create a database 
advanced_1098_li=Use the <code>CreateCluster</code> tool to copy the database to another location and initialize the clustering. Afterwards, you have two databases containing the same data. 
advanced_1099_li=Start two servers (one for each copy of the database) 
advanced_1100_li=You are now ready to connect to the databases with the client application(s) 
advanced_1101_h3=Using the CreateCluster Tool
advanced_1102_p=\ To understand how clustering works, please try out the following example. In this example, the two databases reside on the same computer, but usually, the databases will be on different servers. 
advanced_1103_li=Create two directories\: <code>server1, server2</code>. Each directory will simulate a directory on a computer. 
advanced_1104_li=Start a TCP server pointing to the first directory. You can do this using the command line\: 
advanced_1105_li=Start a second TCP server pointing to the second directory. This will simulate a server running on a second (redundant) computer. You can do this using the command line\: 
advanced_1106_li=Use the <code>CreateCluster</code> tool to initialize clustering. This will automatically create a new, empty database if it does not exist. Run the tool on the command line\: 
advanced_1107_li=You can now connect to the databases using an application or the H2 Console using the JDBC URL <code>jdbc\:h2\:tcp\://localhost\:9101,localhost\:9102/~/test</code> 
advanced_1108_li=If you stop a server (by killing the process), you will notice that the other machine continues to work, and therefore the database is still accessible. 
advanced_1109_li=To restore the cluster, you first need to delete the database that failed, then restart the server that was stopped, and re-run the <code>CreateCluster</code> tool. 
advanced_1110_h3=Detect Which Cluster Instances are Running
advanced_1111_p=\ To find out which cluster nodes are currently running, execute the following SQL statement\: 
advanced_1112_p=\ If the result is <code>''</code> (two single quotes), then the cluster mode is disabled. Otherwise, the list of servers is returned, enclosed in single quote. Example\: <code>'server1\:9191,server2\:9191'</code>. 
advanced_1113_h3=Clustering Algorithm and Limitations
advanced_1114_p=\ Read-only queries are only executed against the first cluster node, but all other statements are executed against all nodes. There is currently no load balancing made to avoid problems with transactions. The following functions may yield different results on different cluster nodes and must be executed with care\: <code>RANDOM_UUID(), SECURE_RAND(), SESSION_ID(), MEMORY_FREE(), MEMORY_USED(), CSVREAD(), CSVWRITE(), RAND()</code> [when not using a seed]. Those functions should not be used directly in modifying statements (for example <code>INSERT, UPDATE, MERGE</code>). However, they can be used in read-only statements and the result can then be used for modifying statements. Using auto-increment and identity columns is currently not supported. Instead, sequence values need to be manually requested and then used to insert data (using two statements). 
advanced_1115_p=\ When using the cluster modes, result sets are read fully in memory by the client, so that there is no problem if the server dies that executed the query. Result sets must fit in memory on the client side. 
advanced_1116_p=\ The SQL statement <code>SET AUTOCOMMIT FALSE</code> is not supported in the cluster mode. To disable autocommit, the method <code>Connection.setAutoCommit(false)</code> needs to be called. 
advanced_1117_p=\ It is possible that a transaction from one connection overtakes a transaction from a different connection. Depending on the operations, this might result in different results, for example when conditionally incrementing a value in a row. 
advanced_1118_h2=Two Phase Commit
advanced_1119_p=\ The two phase commit protocol is supported. 2-phase-commit works as follows\: 
advanced_1120_li=Autocommit needs to be switched off 
advanced_1121_li=A transaction is started, for example by inserting a row 
advanced_1122_li=The transaction is marked 'prepared' by executing the SQL statement <code>PREPARE COMMIT transactionName</code> 
advanced_1123_li=The transaction can now be committed or rolled back 
advanced_1124_li=If a problem occurs before the transaction was successfully committed or rolled back (for example because a network problem occurred), the transaction is in the state 'in-doubt' 
advanced_1125_li=When re-connecting to the database, the in-doubt transactions can be listed with <code>SELECT * FROM INFORMATION_SCHEMA.IN_DOUBT</code> 
advanced_1126_li=Each transaction in this list must now be committed or rolled back by executing <code>COMMIT TRANSACTION transactionName</code> or <code>ROLLBACK TRANSACTION transactionName</code> 
advanced_1127_li=The database needs to be closed and re-opened to apply the changes 
advanced_1128_h2=Compatibility
advanced_1129_p=\ This database is (up to a certain point) compatible to other databases such as HSQLDB, MySQL and PostgreSQL. There are certain areas where H2 is incompatible. 
advanced_1130_h3=Transaction Commit when Autocommit is On
advanced_1131_p=\ At this time, this database engine commits a transaction (if autocommit is switched on) just before returning the result. For a query, this means the transaction is committed even before the application scans through the result set, and before the result set is closed. Other database engines may commit the transaction in this case when the result set is closed. 
advanced_1132_h3=Keywords / Reserved Words
advanced_1133_p=\ There is a list of keywords that can't be used as identifiers (table names, column names and so on), unless they are quoted (surrounded with double quotes). The list is currently\: 
advanced_1134_code=\ CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT, EXISTS, FALSE, FOR, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, UNIQUE, WHERE 
advanced_1135_p=\ Certain words of this list are keywords because they are functions that can be used without '()' for compatibility, for example <code>CURRENT_TIMESTAMP</code>. 
advanced_1136_h2=Standards Compliance
advanced_1137_p=\ This database tries to be as much standard compliant as possible. For the SQL language, ANSI/ISO is the main standard. There are several versions that refer to the release date\: SQL-92, SQL\:1999, and SQL\:2003. Unfortunately, the standard documentation is not freely available. Another problem is that important features are not standardized. Whenever this is the case, this database tries to be compatible to other databases. 
advanced_1138_h3=Supported Character Sets, Character Encoding, and Unicode
advanced_1139_p=\ H2 internally uses Unicode, and supports all character encoding systems and character sets supported by the virtual machine you use. 
advanced_1140_h2=Run as Windows Service
advanced_1141_p=\ Using a native wrapper / adapter, Java applications can be run as a Windows Service. There are various tools available to do that. The Java Service Wrapper from <a href\="http\://wrapper.tanukisoftware.org">Tanuki Software, Inc.</a> is included in the installation. Batch files are provided to install, start, stop and uninstall the H2 Database Engine Service. This service contains the TCP Server and the H2 Console web application. The batch files are located in the directory <code>h2/service</code>. 
advanced_1142_p=\ The service wrapper bundled with H2 is a 32-bit version. To use a 64-bit version of Windows (x64), you need to use a 64-bit version of the wrapper, for example the one from <a href\="http\://www.krenger.ch/blog/java-service-wrapper-3-5-14-for-windows-x64/"> Simon Krenger</a>. 
advanced_1143_p=\ When running the database as a service, absolute path should be used. Using <code>~</code> in the database URL is problematic in this case, because it means to use the home directory of the current user. The service might run without or with the wrong user, so that the database files might end up in an unexpected place. 
advanced_1144_h3=Install the Service
advanced_1145_p=\ The service needs to be registered as a Windows Service first. To do that, double click on <code>1_install_service.bat</code>. If successful, a command prompt window will pop up and disappear immediately. If not, a message will appear. 
advanced_1146_h3=Start the Service
advanced_1147_p=\ You can start the H2 Database Engine Service using the service manager of Windows, or by double clicking on <code>2_start_service.bat</code>. Please note that the batch file does not print an error message if the service is not installed. 
advanced_1148_h3=Connect to the H2 Console
advanced_1149_p=\ After installing and starting the service, you can connect to the H2 Console application using a browser. Double clicking on <code>3_start_browser.bat</code> to do that. The default port (8082) is hard coded in the batch file. 
advanced_1150_h3=Stop the Service
advanced_1151_p=\ To stop the service, double click on <code>4_stop_service.bat</code>. Please note that the batch file does not print an error message if the service is not installed or started. 
advanced_1152_h3=Uninstall the Service
advanced_1153_p=\ To uninstall the service, double click on <code>5_uninstall_service.bat</code>. If successful, a command prompt window will pop up and disappear immediately. If not, a message will appear. 
advanced_1154_h3=Additional JDBC drivers
advanced_1155_p=\ To use other databases (for example MySQL), the location of the JDBC drivers of those databases need to be added to the environment variables <code>H2DRIVERS</code> or <code>CLASSPATH</code> before installing the service. Multiple drivers can be set; each entry needs to be separated with a <code>;</code> (Windows) or <code>\:</code> (other operating systems). Spaces in the path names are supported. The settings must not be quoted. 
advanced_1156_h2=ODBC Driver
advanced_1157_p=\ This database does not come with its own ODBC driver at this time, but it supports the PostgreSQL network protocol. Therefore, the PostgreSQL ODBC driver can be used. Support for the PostgreSQL network protocol is quite new and should be viewed as experimental. It should not be used for production applications. 
advanced_1158_p=\ To use the PostgreSQL ODBC driver on 64 bit versions of Windows, first run <code>c\:/windows/syswow64/odbcad32.exe</code>. At this point you set up your DSN just like you would on any other system. See also\: <a href\="http\://archives.postgresql.org/pgsql-odbc/2005-09/msg00125.php">Re\: ODBC Driver on Windows 64 bit</a> 
advanced_1159_h3=ODBC Installation
advanced_1160_p=\ First, the ODBC driver must be installed. Any recent PostgreSQL ODBC driver should work, however version 8.2 (<code>psqlodbc-08_02*</code>) or newer is recommended. The Windows version of the PostgreSQL ODBC driver is available at <a href\="http\://www.postgresql.org/ftp/odbc/versions/msi">http\://www.postgresql.org/ftp/odbc/versions/msi</a>. 
advanced_1161_h3=Starting the Server
advanced_1162_p=\ After installing the ODBC driver, start the H2 Server using the command line\: 
advanced_1163_p=\ The PG Server (PG for PostgreSQL protocol) is started as well. By default, databases are stored in the current working directory where the server is started. Use <code>-baseDir</code> to save databases in another directory, for example the user home directory\: 
advanced_1164_p=\ The PG server can be started and stopped from within a Java application as follows\: 
advanced_1165_p=\ By default, only connections from localhost are allowed. To allow remote connections, use <code>-pgAllowOthers</code> when starting the server. 
advanced_1166_p=\ To map an ODBC database name to a different JDBC database name, use the option <code>-key</code> when starting the server. Please note only one mapping is allowed. The following will map the ODBC database named <code>TEST</code> to the database URL <code>jdbc\:h2\:~/data/test;cipher\=aes</code>\: 
advanced_1167_h3=ODBC Configuration
advanced_1168_p=\ After installing the driver, a new Data Source must be added. In Windows, run <code>odbcad32.exe</code> to open the Data Source Administrator. Then click on 'Add...' and select the PostgreSQL Unicode driver. Then click 'Finish'. You will be able to change the connection properties. The property column represents the property key in the <code>odbc.ini</code> file (which may be different from the GUI). 
advanced_1169_th=Property
advanced_1170_th=Example
advanced_1171_th=Remarks
advanced_1172_td=Data Source
advanced_1173_td=H2 Test
advanced_1174_td=The name of the ODBC Data Source
advanced_1175_td=Database
advanced_1176_td=~/test;ifexists\=true
advanced_1177_td=\ The database name. This can include connections settings. By default, the database is stored in the current working directory where the Server is started except when the -baseDir setting is used. The name must be at least 3 characters. 
advanced_1178_td=Servername
advanced_1179_td=localhost
advanced_1180_td=The server name or IP address.
advanced_1181_td=By default, only remote connections are allowed
advanced_1182_td=Username
advanced_1183_td=sa
advanced_1184_td=The database user name.
advanced_1185_td=SSL
advanced_1186_td=false (disabled)
advanced_1187_td=At this time, SSL is not supported.
advanced_1188_td=Port
advanced_1189_td=5435
advanced_1190_td=The port where the PG Server is listening.
advanced_1191_td=Password
advanced_1192_td=sa
advanced_1193_td=The database password.
advanced_1194_p=\ To improve performance, please enable 'server side prepare' under Options / Datasource / Page 2 / Server side prepare. 
advanced_1195_p=\ Afterwards, you may use this data source. 
advanced_1196_h3=PG Protocol Support Limitations
advanced_1197_p=\ At this time, only a subset of the PostgreSQL network protocol is implemented. Also, there may be compatibility problems on the SQL level, with the catalog, or with text encoding. Problems are fixed as they are found. Currently, statements can not be canceled when using the PG protocol. Also, H2 does not provide index meta over ODBC. 
advanced_1198_p=\ PostgreSQL ODBC Driver Setup requires a database password; that means it is not possible to connect to H2 databases without password. This is a limitation of the ODBC driver. 
advanced_1199_h3=Security Considerations
advanced_1200_p=\ Currently, the PG Server does not support challenge response or encrypt passwords. This may be a problem if an attacker can listen to the data transferred between the ODBC driver and the server, because the password is readable to the attacker. Also, it is currently not possible to use encrypted SSL connections. Therefore the ODBC driver should not be used where security is important. 
advanced_1201_p=\ The first connection that opens a database using the PostgreSQL server needs to be an administrator user. Subsequent connections don't need to be opened by an administrator. 
advanced_1202_h3=Using Microsoft Access
advanced_1203_p=\ When using Microsoft Access to edit data in a linked H2 table, you may need to enable the following option\: Tools - Options - Edit/Find - ODBC fields. 
advanced_1204_h2=Using H2 in Microsoft .NET
advanced_1205_p=\ The database can be used from Microsoft .NET even without using Java, by using IKVM.NET. You can access a H2 database on .NET using the JDBC API, or using the ADO.NET interface. 
advanced_1206_h3=Using the ADO.NET API on .NET
advanced_1207_p=\ An implementation of the ADO.NET interface is available in the open source project <a href\="http\://code.google.com/p/h2sharp">H2Sharp</a>. 
advanced_1208_h3=Using the JDBC API on .NET
advanced_1209_li=Install the .NET Framework from <a href\="http\://www.microsoft.com">Microsoft</a>. Mono has not yet been tested. 
advanced_1210_li=Install <a href\="http\://www.ikvm.net">IKVM.NET</a>. 
advanced_1211_li=Copy the <code>h2*.jar</code> file to <code>ikvm/bin</code> 
advanced_1212_li=Run the H2 Console using\: <code>ikvm -jar h2*.jar</code> 
advanced_1213_li=Convert the H2 Console to an <code>.exe</code> file using\: <code>ikvmc -target\:winexe h2*.jar</code>. You may ignore the warnings. 
advanced_1214_li=Create a <code>.dll</code> file using (change the version accordingly)\: <code>ikvmc.exe -target\:library -version\:1.0.69.0 h2*.jar</code> 
advanced_1215_p=\ If you want your C\# application use H2, you need to add the <code>h2.dll</code> and the <code>IKVM.OpenJDK.ClassLibrary.dll</code> to your C\# solution. Here some sample code\: 
advanced_1216_h2=ACID
advanced_1217_p=\ In the database world, ACID stands for\: 
advanced_1218_li=Atomicity\: transactions must be atomic, meaning either all tasks are performed or none. 
advanced_1219_li=Consistency\: all operations must comply with the defined constraints. 
advanced_1220_li=Isolation\: transactions must be isolated from each other. 
advanced_1221_li=Durability\: committed transaction will not be lost. 
advanced_1222_h3=Atomicity
advanced_1223_p=\ Transactions in this database are always atomic. 
advanced_1224_h3=Consistency
advanced_1225_p=\ By default, this database is always in a consistent state. Referential integrity rules are enforced except when explicitly disabled. 
advanced_1226_h3=Isolation
advanced_1227_p=\ For H2, as with most other database systems, the default isolation level is 'read committed'. This provides better performance, but also means that transactions are not completely isolated. H2 supports the transaction isolation levels 'serializable', 'read committed', and 'read uncommitted'. 
advanced_1228_h3=Durability
advanced_1229_p=\ This database does not guarantee that all committed transactions survive a power failure. Tests show that all databases sometimes lose transactions on power failure (for details, see below). Where losing transactions is not acceptable, a laptop or UPS (uninterruptible power supply) should be used. If durability is required for all possible cases of hardware failure, clustering should be used, such as the H2 clustering mode. 
advanced_1230_h2=Durability Problems
advanced_1231_p=\ Complete durability means all committed transaction survive a power failure. Some databases claim they can guarantee durability, but such claims are wrong. A durability test was run against H2, HSQLDB, PostgreSQL, and Derby. All of those databases sometimes lose committed transactions. The test is included in the H2 download, see <code>org.h2.test.poweroff.Test</code>. 
advanced_1232_h3=Ways to (Not) Achieve Durability
advanced_1233_p=\ Making sure that committed transactions are not lost is more complicated than it seems first. To guarantee complete durability, a database must ensure that the log record is on the hard drive before the commit call returns. To do that, databases use different methods. One is to use the 'synchronous write' file access mode. In Java, <code>RandomAccessFile</code> supports the modes <code>rws</code> and <code>rwd</code>\: 
advanced_1234_code=rwd
advanced_1235_li=\: every update to the file's content is written synchronously to the underlying storage device. 
advanced_1236_code=rws
advanced_1237_li=\: in addition to <code>rwd</code>, every update to the metadata is written synchronously.
advanced_1238_p=\ A test (<code>org.h2.test.poweroff.TestWrite</code>) with one of those modes achieves around 50 thousand write operations per second. Even when the operating system write buffer is disabled, the write rate is around 50 thousand operations per second. This feature does not force changes to disk because it does not flush all buffers. The test updates the same byte in the file again and again. If the hard drive was able to write at this rate, then the disk would need to make at least 50 thousand revolutions per second, or 3 million RPM (revolutions per minute). There are no such hard drives. The hard drive used for the test is about 7200 RPM, or about 120 revolutions per second. There is an overhead, so the maximum write rate must be lower than that. 
advanced_1239_p=\ Calling <code>fsync</code> flushes the buffers. There are two ways to do that in Java\: 
advanced_1240_code=FileDescriptor.sync()
advanced_1241_li=. The documentation says that this forces all system buffers to synchronize with the underlying device. This method is supposed to return after all in-memory modified copies of buffers associated with this file descriptor have been written to the physical medium. 
advanced_1242_code=FileChannel.force()
advanced_1243_li=. This method is supposed to force any updates to this channel's file to be written to the storage device that contains it. 
advanced_1244_p=\ By default, MySQL calls <code>fsync</code> for each commit. When using one of those methods, only around 60 write operations per second can be achieved, which is consistent with the RPM rate of the hard drive used. Unfortunately, even when calling <code>FileDescriptor.sync()</code> or <code>FileChannel.force()</code>, data is not always persisted to the hard drive, because most hard drives do not obey <code>fsync()</code>\: see <a href\="http\://hardware.slashdot.org/article.pl?sid\=05/05/13/0529252">Your Hard Drive Lies to You</a>. In Mac OS X, <code>fsync</code> does not flush hard drive buffers. See <a href\="http\://lists.apple.com/archives/darwin-dev/2005/Feb/msg00072.html">Bad fsync?</a>. So the situation is confusing, and tests prove there is a problem. 
advanced_1245_p=\ Trying to flush hard drive buffers is hard, and if you do the performance is very bad. First you need to make sure that the hard drive actually flushes all buffers. Tests show that this can not be done in a reliable way. Then the maximum number of transactions is around 60 per second. Because of those reasons, the default behavior of H2 is to delay writing committed transactions. 
advanced_1246_p=\ In H2, after a power failure, a bit more than one second of committed transactions may be lost. To change the behavior, use <code>SET WRITE_DELAY</code> and <code>CHECKPOINT SYNC</code>. Most other databases support commit delay as well. In the performance comparison, commit delay was used for all databases that support it. 
advanced_1247_h3=Running the Durability Test
advanced_1248_p=\ To test the durability / non-durability of this and other databases, you can use the test application in the package <code>org.h2.test.poweroff</code>. Two computers with network connection are required to run this test. One computer just listens, while the test application is run (and power is cut) on the other computer. The computer with the listener application opens a TCP/IP port and listens for an incoming connection. The second computer first connects to the listener, and then created the databases and starts inserting records. The connection is set to 'autocommit', which means after each inserted record a commit is performed automatically. Afterwards, the test computer notifies the listener that this record was inserted successfully. The listener computer displays the last inserted record number every 10 seconds. Now, switch off the power manually, then restart the computer, and run the application again. You will find out that in most cases, none of the databases contains all the records that the listener computer knows about. For details, please consult the source code of the listener and test application. 
advanced_1249_h2=Using the Recover Tool
advanced_1250_p=\ The <code>Recover</code> tool can be used to extract the contents of a database file, even if the database is corrupted. It also extracts the content of the transaction log and large objects (CLOB or BLOB). To run the tool, type on the command line\: 
advanced_1251_p=\ For each database in the current directory, a text file will be created. This file contains raw insert statements (for the data) and data definition (DDL) statements to recreate the schema of the database. This file can be executed using the <code>RunScript</code> tool or a <code>RUNSCRIPT FROM</code> SQL statement. The script includes at least one <code>CREATE USER</code> statement. If you run the script against a database that was created with the same user, or if there are conflicting users, running the script will fail. Consider running the script against a database that was created with a user name that is not in the script. 
advanced_1252_p=\ The <code>Recover</code> tool creates a SQL script from database file. It also processes the transaction log. 
advanced_1253_p=\ To verify the database can recover at any time, append <code>;RECOVER_TEST\=64</code> to the database URL in your test environment. This will simulate an application crash after each 64 writes to the database file. A log file named <code>databaseName.h2.db.log</code> is created that lists the operations. The recovery is tested using an in-memory file system, that means it may require a larger heap setting. 
advanced_1254_h2=File Locking Protocols
advanced_1255_p=\ Multiple concurrent connections to the same database are supported, however a database file can only be open for reading and writing (in embedded mode) by one process at the same time. Otherwise, the processes would overwrite each others data and corrupt the database file. To protect against this problem, whenever a database is opened, a lock file is created to signal other processes that the database is in use. If the database is closed, or if the process that opened the database stops normally, this lock file is deleted. 
advanced_1256_p=\ In special cases (if the process did not terminate normally, for example because there was a power failure), the lock file is not deleted by the process that created it. That means the existence of the lock file is not a safe protocol for file locking. However, this software uses a challenge-response protocol to protect the database files. There are two methods (algorithms) implemented to provide both security (that is, the same database files cannot be opened by two processes at the same time) and simplicity (that is, the lock file does not need to be deleted manually by the user). The two methods are 'file method' and 'socket methods'. 
advanced_1257_p=\ The file locking protocols (except the file locking method 'FS') have the following limitation\: if a shared file system is used, and the machine with the lock owner is sent to sleep (standby or hibernate), another machine may take over. If the machine that originally held the lock wakes up, the database may become corrupt. If this situation can occur, the application must ensure the database is closed when the application is put to sleep. 
advanced_1258_h3=File Locking Method 'File'
advanced_1259_p=\ The default method for database file locking for version 1.3 and older is the 'File Method'. The algorithm is\: 
advanced_1260_li=If the lock file does not exist, it is created (using the atomic operation <code>File.createNewFile</code>). Then, the process waits a little bit (20 ms) and checks the file again. If the file was changed during this time, the operation is aborted. This protects against a race condition when one process deletes the lock file just after another one create it, and a third process creates the file again. It does not occur if there are only two writers. 
advanced_1261_li=\ If the file can be created, a random number is inserted together with the locking method ('file'). Afterwards, a watchdog thread is started that checks regularly (every second once by default) if the file was deleted or modified by another (challenger) thread / process. Whenever that occurs, the file is overwritten with the old data. The watchdog thread runs with high priority so that a change to the lock file does not get through undetected even if the system is very busy. However, the watchdog thread does use very little resources (CPU time), because it waits most of the time. Also, the watchdog only reads from the hard disk and does not write to it. 
advanced_1262_li=\ If the lock file exists and was recently modified, the process waits for some time (up to two seconds). If it was still changed, an exception is thrown (database is locked). This is done to eliminate race conditions with many concurrent writers. Afterwards, the file is overwritten with a new version (challenge). After that, the thread waits for 2 seconds. If there is a watchdog thread protecting the file, he will overwrite the change and this process will fail to lock the database. However, if there is no watchdog thread, the lock file will still be as written by this thread. In this case, the file is deleted and atomically created again. The watchdog thread is started in this case and the file is locked. 
advanced_1263_p=\ This algorithm is tested with over 100 concurrent threads. In some cases, when there are many concurrent threads trying to lock the database, they block each other (meaning the file cannot be locked by any of them) for some time. However, the file never gets locked by two threads at the same time. However using that many concurrent threads / processes is not the common use case. Generally, an application should throw an error to the user if it cannot open a database, and not try again in a (fast) loop. 
advanced_1264_h3=File Locking Method 'Socket'
advanced_1265_p=\ There is a second locking mechanism implemented, but disabled by default. To use it, append <code>;FILE_LOCK\=SOCKET</code> to the database URL. The algorithm is\: 
advanced_1266_li=If the lock file does not exist, it is created. Then a server socket is opened on a defined port, and kept open. The port and IP address of the process that opened the database is written into the lock file. 
advanced_1267_li=If the lock file exists, and the lock method is 'file', then the software switches to the 'file' method. 
advanced_1268_li=If the lock file exists, and the lock method is 'socket', then the process checks if the port is in use. If the original process is still running, the port is in use and this process throws an exception (database is in use). If the original process died (for example due to a power failure, or abnormal termination of the virtual machine), then the port was released. The new process deletes the lock file and starts again. 
advanced_1269_p=\ This method does not require a watchdog thread actively polling (reading) the same file every second. The problem with this method is, if the file is stored on a network share, two processes (running on different computers) could still open the same database files, if they do not have a direct TCP/IP connection. 
advanced_1270_h3=File Locking Method 'FS'
advanced_1271_p=\ This is the default mode for version 1.4 and newer. This database file locking mechanism uses native file system lock on the database file. No *.lock.db file is created in this case, and no background thread is started. This mechanism may not work on all systems as expected. Some systems allow to lock the same file multiple times within the same virtual machine, and on some system native file locking is not supported or files are not unlocked after a power failure. 
advanced_1272_p=\ To enable this feature, append <code>;FILE_LOCK\=FS</code> to the database URL. 
advanced_1273_p=\ This feature is relatively new. When using it for production, please ensure your system does in fact lock files as expected. 
advanced_1274_h2=Using Passwords
advanced_1275_h3=Using Secure Passwords
advanced_1276_p=\ Remember that weak passwords can be broken regardless of the encryption and security protocols. Don't use passwords that can be found in a dictionary. Appending numbers does not make passwords secure. A way to create good passwords that can be remembered is\: take the first letters of a sentence, use upper and lower case characters, and creatively include special characters (but it's more important to use a long password than to use special characters). Example\: 
advanced_1277_code=i'sE2rtPiUKtT
advanced_1278_p=\ from the sentence <code>it's easy to remember this password if you know the trick</code>. 
advanced_1279_h3=Passwords\: Using Char Arrays instead of Strings
advanced_1280_p=\ Java strings are immutable objects and cannot be safely 'destroyed' by the application. After creating a string, it will remain in the main memory of the computer at least until it is garbage collected. The garbage collection cannot be controlled by the application, and even if it is garbage collected the data may still remain in memory. It might also be possible that the part of memory containing the password is swapped to disk (if not enough main memory is available), which is a problem if the attacker has access to the swap file of the operating system. 
advanced_1281_p=\ It is a good idea to use char arrays instead of strings for passwords. Char arrays can be cleared (filled with zeros) after use, and therefore the password will not be stored in the swap file. 
advanced_1282_p=\ This database supports using char arrays instead of string to pass user and file passwords. The following code can be used to do that\: 
advanced_1283_p=\ This example requires Java 1.6. When using Swing, use <code>javax.swing.JPasswordField</code>. 
advanced_1284_h3=Passing the User Name and/or Password in the URL
advanced_1285_p=\ Instead of passing the user name as a separate parameter as in <code> Connection conn \= DriverManager. getConnection("jdbc\:h2\:~/test", "sa", "123"); </code> the user name (and/or password) can be supplied in the URL itself\: <code> Connection conn \= DriverManager. getConnection("jdbc\:h2\:~/test;USER\=sa;PASSWORD\=123"); </code> The settings in the URL override the settings passed as a separate parameter. 
advanced_1286_h2=Password Hash
advanced_1287_p=\ Sometimes the database password needs to be stored in a configuration file (for example in the <code>web.xml</code> file). In addition to connecting with the plain text password, this database supports connecting with the password hash. This means that only the hash of the password (and not the plain text password) needs to be stored in the configuration file. This will only protect others from reading or re-constructing the plain text password (even if they have access to the configuration file); it does not protect others from accessing the database using the password hash. 
advanced_1288_p=\ To connect using the password hash instead of plain text password, append <code>;PASSWORD_HASH\=TRUE</code> to the database URL, and replace the password with the password hash. To calculate the password hash from a plain text password, run the following command within the H2 Console tool\: <code>@password_hash &lt;upperCaseUserName&gt; &lt;password&gt;</code>. As an example, if the user name is <code>sa</code> and the password is <code>test</code>, run the command <code>@password_hash SA test</code>. Then use the resulting password hash as you would use the plain text password. When using an encrypted database, then the user password and file password need to be hashed separately. To calculate the hash of the file password, run\: <code>@password_hash file &lt;filePassword&gt;</code>. 
advanced_1289_h2=Protection against SQL Injection
advanced_1290_h3=What is SQL Injection
advanced_1291_p=\ This database engine provides a solution for the security vulnerability known as 'SQL Injection'. Here is a short description of what SQL injection means. Some applications build SQL statements with embedded user input such as\: 
advanced_1292_p=\ If this mechanism is used anywhere in the application, and user input is not correctly filtered or encoded, it is possible for a user to inject SQL functionality or statements by using specially built input such as (in this example) this password\: <code>' OR ''\='</code>. In this case the statement becomes\: 
advanced_1293_p=\ Which is always true no matter what the password stored in the database is. For more information about SQL Injection, see <a href\="\#glossary_links">Glossary and Links</a>. 
advanced_1294_h3=Disabling Literals
advanced_1295_p=\ SQL Injection is not possible if user input is not directly embedded in SQL statements. A simple solution for the problem above is to use a prepared statement\: 
advanced_1296_p=\ This database provides a way to enforce usage of parameters when passing user input to the database. This is done by disabling embedded literals in SQL statements. To do this, execute the statement\: 
advanced_1297_p=\ Afterwards, SQL statements with text and number literals are not allowed any more. That means, SQL statement of the form <code>WHERE NAME\='abc'</code> or <code>WHERE CustomerId\=10</code> will fail. It is still possible to use prepared statements and parameters as described above. Also, it is still possible to generate SQL statements dynamically, and use the Statement API, as long as the SQL statements do not include literals. There is also a second mode where number literals are allowed\: <code>SET ALLOW_LITERALS NUMBERS</code>. To allow all literals, execute <code>SET ALLOW_LITERALS ALL</code> (this is the default setting). Literals can only be enabled or disabled by an administrator. 
advanced_1298_h3=Using Constants
advanced_1299_p=\ Disabling literals also means disabling hard-coded 'constant' literals. This database supports defining constants using the <code>CREATE CONSTANT</code> command. Constants can be defined only when literals are enabled, but used even when literals are disabled. To avoid name clashes with column names, constants can be defined in other schemas\: 
advanced_1300_p=\ Even when literals are enabled, it is better to use constants instead of hard-coded number or text literals in queries or views. With constants, typos are found at compile time, the source code is easier to understand and change. 
advanced_1301_h3=Using the ZERO() Function
advanced_1302_p=\ It is not required to create a constant for the number 0 as there is already a built-in function <code>ZERO()</code>\: 
advanced_1303_h2=Protection against Remote Access
advanced_1304_p=\ By default this database does not allow connections from other machines when starting the H2 Console, the TCP server, or the PG server. Remote access can be enabled using the command line options <code>-webAllowOthers, -tcpAllowOthers, -pgAllowOthers</code>. If you enable remote access, please also consider using the options <code>-baseDir, -ifExists</code>, so that remote users can not create new databases or access existing databases with weak passwords. When using the option <code>-baseDir</code>, only databases within that directory may be accessed. Ensure the existing accessible databases are protected using strong passwords. 
advanced_1305_h2=Restricting Class Loading and Usage
advanced_1306_p=\ By default there is no restriction on loading classes and executing Java code for admins. That means an admin may call system functions such as <code>System.setProperty</code> by executing\: 
advanced_1307_p=\ To restrict users (including admins) from loading classes and executing code, the list of allowed classes can be set in the system property <code>h2.allowedClasses</code> in the form of a comma separated list of classes or patterns (items ending with <code>*</code>). By default all classes are allowed. Example\: 
advanced_1308_p=\ This mechanism is used for all user classes, including database event listeners, trigger classes, user-defined functions, user-defined aggregate functions, and JDBC driver classes (with the exception of the H2 driver) when using the H2 Console. 
advanced_1309_h2=Security Protocols
advanced_1310_p=\ The following paragraphs document the security protocols used in this database. These descriptions are very technical and only intended for security experts that already know the underlying security primitives. 
advanced_1311_h3=User Password Encryption
advanced_1312_p=\ When a user tries to connect to a database, the combination of user name, @, and password are hashed using SHA-256, and this hash value is transmitted to the database. This step does not protect against an attacker that re-uses the value if he is able to listen to the (unencrypted) transmission between the client and the server. But, the passwords are never transmitted as plain text, even when using an unencrypted connection between client and server. That means if a user reuses the same password for different things, this password is still protected up to some point. See also 'RFC 2617 - HTTP Authentication\: Basic and Digest Access Authentication' for more information. 
advanced_1313_p=\ When a new database or user is created, a new random salt value is generated. The size of the salt is 64 bits. Using the random salt reduces the risk of an attacker pre-calculating hash values for many different (commonly used) passwords. 
advanced_1314_p=\ The combination of user-password hash value (see above) and salt is hashed using SHA-256. The resulting value is stored in the database. When a user tries to connect to the database, the database combines user-password hash value with the stored salt value and calculates the hash value. Other products use multiple iterations (hash the hash value again and again), but this is not done in this product to reduce the risk of denial of service attacks (where the attacker tries to connect with bogus passwords, and the server spends a lot of time calculating the hash value for each password). The reasoning is\: if the attacker has access to the hashed passwords, he also has access to the data in plain text, and therefore does not need the password any more. If the data is protected by storing it on another computer and only accessible remotely, then the iteration count is not required at all. 
advanced_1315_h3=File Encryption
advanced_1316_p=\ The database files can be encrypted using the AES-128 algorithm. 
advanced_1317_p=\ When a user tries to connect to an encrypted database, the combination of <code>file@</code> and the file password is hashed using SHA-256. This hash value is transmitted to the server. 
advanced_1318_p=\ When a new database file is created, a new cryptographically secure random salt value is generated. The size of the salt is 64 bits. The combination of the file password hash and the salt value is hashed 1024 times using SHA-256. The reason for the iteration is to make it harder for an attacker to calculate hash values for common passwords. 
advanced_1319_p=\ The resulting hash value is used as the key for the block cipher algorithm. Then, an initialization vector (IV) key is calculated by hashing the key again using SHA-256. This is to make sure the IV is unknown to the attacker. The reason for using a secret IV is to protect against watermark attacks. 
advanced_1320_p=\ Before saving a block of data (each block is 8 bytes long), the following operations are executed\: first, the IV is calculated by encrypting the block number with the IV key (using the same block cipher algorithm). This IV is combined with the plain text using XOR. The resulting data is encrypted using the AES-128 algorithm. 
advanced_1321_p=\ When decrypting, the operation is done in reverse. First, the block is decrypted using the key, and then the IV is calculated combined with the decrypted text using XOR. 
advanced_1322_p=\ Therefore, the block cipher mode of operation is CBC (cipher-block chaining), but each chain is only one block long. The advantage over the ECB (electronic codebook) mode is that patterns in the data are not revealed, and the advantage over multi block CBC is that flipped cipher text bits are not propagated to flipped plaintext bits in the next block. 
advanced_1323_p=\ Database encryption is meant for securing the database while it is not in use (stolen laptop and so on). It is not meant for cases where the attacker has access to files while the database is in use. When he has write access, he can for example replace pieces of files with pieces of older versions and manipulate data like this. 
advanced_1324_p=\ File encryption slows down the performance of the database engine. Compared to unencrypted mode, database operations take about 2.5 times longer using AES (embedded mode). 
advanced_1325_h3=Wrong Password / User Name Delay
advanced_1326_p=\ To protect against remote brute force password attacks, the delay after each unsuccessful login gets double as long. Use the system properties <code>h2.delayWrongPasswordMin</code> and <code>h2.delayWrongPasswordMax</code> to change the minimum (the default is 250 milliseconds) or maximum delay (the default is 4000 milliseconds, or 4 seconds). The delay only applies for those using the wrong password. Normally there is no delay for a user that knows the correct password, with one exception\: after using the wrong password, there is a delay of up to (randomly distributed) the same delay as for a wrong password. This is to protect against parallel brute force attacks, so that an attacker needs to wait for the whole delay. Delays are synchronized. This is also required to protect against parallel attacks. 
advanced_1327_p=\ There is only one exception message for both wrong user and for wrong password, to make it harder to get the list of user names. It is not possible from the stack trace to see if the user name was wrong or the password. 
advanced_1328_h3=HTTPS Connections
advanced_1329_p=\ The web server supports HTTP and HTTPS connections using <code>SSLServerSocket</code>. There is a default self-certified certificate to support an easy starting point, but custom certificates are supported as well. 
advanced_1330_h2=SSL/TLS Connections
advanced_1331_p=\ Remote SSL/TLS connections are supported using the Java Secure Socket Extension (<code>SSLServerSocket, SSLSocket</code>). By default, anonymous SSL is enabled. The default cipher suite is <code>SSL_DH_anon_WITH_RC4_128_MD5</code>. 
advanced_1332_p=\ To use your own keystore, set the system properties <code>javax.net.ssl.keyStore</code> and <code>javax.net.ssl.keyStorePassword</code> before starting the H2 server and client. See also <a href\="http\://java.sun.com/javase/6/docs/technotes/guides/security/jsse/JSSERefGuide.html\#CustomizingStores"> Customizing the Default Key and Trust Stores, Store Types, and Store Passwords</a> for more information. 
advanced_1333_p=\ To disable anonymous SSL, set the system property <code>h2.enableAnonymousSSL</code> to false. 
advanced_1334_h2=Universally Unique Identifiers (UUID)
advanced_1335_p=\ This database supports UUIDs. Also supported is a function to create new UUIDs using a cryptographically strong pseudo random number generator. With random UUIDs, the chance of two having the same value can be calculated using the probability theory. See also 'Birthday Paradox'. Standardized randomly generated UUIDs have 122 random bits. 4 bits are used for the version (Randomly generated UUID), and 2 bits for the variant (Leach-Salz). This database supports generating such UUIDs using the built-in function <code>RANDOM_UUID()</code>. Here is a small program to estimate the probability of having two identical UUIDs after generating a number of values\: 
advanced_1336_p=\ Some values are\: 
advanced_1337_th=Number of UUIs
advanced_1338_th=Probability of Duplicates
advanced_1339_td=2^36\=68'719'476'736
advanced_1340_td=0.000'000'000'000'000'4
advanced_1341_td=2^41\=2'199'023'255'552
advanced_1342_td=0.000'000'000'000'4
advanced_1343_td=2^46\=70'368'744'177'664
advanced_1344_td=0.000'000'000'4
advanced_1345_p=\ To help non-mathematicians understand what those numbers mean, here a comparison\: one's annual risk of being hit by a meteorite is estimated to be one chance in 17 billion, that means the probability is about 0.000'000'000'06. 
advanced_1346_h2=Recursive Queries
advanced_1347_p=\ H2 has experimental support for recursive queries using so called "common table expressions" (CTE). Examples\: 
advanced_1348_p=\ Limitations\: Recursive queries need to be of the type <code>UNION ALL</code>, and the recursion needs to be on the second part of the query. No tables or views with the name of the table expression may exist. Different table expression names need to be used when using multiple distinct table expressions within the same transaction and for the same session. All columns of the table expression are of type <code>VARCHAR</code>, and may need to be cast to the required data type. Views with recursive queries are not supported. Subqueries and <code>INSERT INTO ... FROM</code> with recursive queries are not supported. Parameters are only supported within the last <code>SELECT</code> statement (a workaround is to use session variables like <code>@start</code> within the table expression). The syntax is\: 
advanced_1349_h2=Settings Read from System Properties
advanced_1350_p=\ Some settings of the database can be set on the command line using <code>-DpropertyName\=value</code>. It is usually not required to change those settings manually. The settings are case sensitive. Example\: 
advanced_1351_p=\ The current value of the settings can be read in the table <code>INFORMATION_SCHEMA.SETTINGS</code>. 
advanced_1352_p=\ For a complete list of settings, see <a href\="../javadoc/org/h2/engine/SysProperties.html">SysProperties</a>. 
advanced_1353_h2=Setting the Server Bind Address
advanced_1354_p=\ Usually server sockets accept connections on any/all local addresses. This may be a problem on multi-homed hosts. To bind only to one address, use the system property <code>h2.bindAddress</code>. This setting is used for both regular server sockets and for SSL server sockets. IPv4 and IPv6 address formats are supported. 
advanced_1355_h2=Pluggable File System
advanced_1356_p=\ This database supports a pluggable file system API. The file system implementation is selected using a file name prefix. Internally, the interfaces are very similar to the Java 7 NIO2 API, but do not (yet) use or require Java 7. The following file systems are included\: 
advanced_1357_code=zip\:
advanced_1358_li=\ read-only zip-file based file system. Format\: <code>zip\:/zipFileName\!/fileName</code>. 
advanced_1359_code=split\:
advanced_1360_li=\ file system that splits files in 1 GB files (stackable with other file systems). 
advanced_1361_code=nio\:
advanced_1362_li=\ file system that uses <code>FileChannel</code> instead of <code>RandomAccessFile</code> (faster in some operating systems). 
advanced_1363_code=nioMapped\:
advanced_1364_li=\ file system that uses memory mapped files (faster in some operating systems). Please note that there currently is a file size limitation of 2 GB when using this file system when using a 32-bit JVM. To work around this limitation, combine it with the split file system\: <code>split\:nioMapped\:test</code>. 
advanced_1365_code=memFS\:
advanced_1366_li=\ in-memory file system (slower than mem; experimental; mainly used for testing the database engine itself). 
advanced_1367_code=memLZF\:
advanced_1368_li=\ compressing in-memory file system (slower than memFS but uses less memory; experimental; mainly used for testing the database engine itself). 
advanced_1369_p=\ As an example, to use the the <code>nio</code> file system, use the following database URL\: <code>jdbc\:h2\:nio\:~/test</code>. 
advanced_1370_p=\ To register a new file system, extend the classes <code>org.h2.store.fs.FilePath, FileBase</code>, and call the method <code>FilePath.register</code> before using it. 
advanced_1371_p=\ For input streams (but not for random access files), URLs may be used in addition to the registered file systems. Example\: <code>jar\:file\:///c\:/temp/example.zip\!/org/example/nested.csv</code>. To read a stream from the classpath, use the prefix <code>classpath\:</code>, as in <code>classpath\:/org/h2/samples/newsfeed.sql</code>. 
advanced_1372_h2=Split File System
advanced_1373_p=\ The file system prefix <code>split\:</code> is used to split logical files into multiple physical files, for example so that a database can get larger than the maximum file system size of the operating system. If the logical file is larger than the maximum file size, then the file is split as follows\: 
advanced_1374_code=&lt;fileName&gt;
advanced_1375_li=\ (first block, is always created) 
advanced_1376_code=&lt;fileName&gt;.1.part
advanced_1377_li=\ (second block) 
advanced_1378_p=\ More physical files (<code>*.2.part, *.3.part</code>) are automatically created / deleted if needed. The maximum physical file size of a block is 2^30 bytes, which is also called 1 GiB or 1 GB. However this can be changed if required, by specifying the block size in the file name. The file name format is\: <code>split\:&lt;x&gt;\:&lt;fileName&gt;</code> where the file size per block is 2^x. For 1 MiB block sizes, use x \= 20 (because 2^20 is 1 MiB). The following file name means the logical file is split into 1 MiB blocks\: <code>split\:20\:test.h2.db</code>. An example database URL for this case is <code>jdbc\:h2\:split\:20\:~/test</code>. 
advanced_1379_h2=Database Upgrade
advanced_1380_p=\ In version 1.2, H2 introduced a new file store implementation which is incompatible to the one used in versions &lt; 1.2. To automatically convert databases to the new file store, it is necessary to include an additional jar file. The file can be found at <a href\="http\://h2database.com/h2mig_pagestore_addon.jar">http\://h2database.com/h2mig_pagestore_addon.jar</a> . If this file is in the classpath, every connect to an older database will result in a conversion process. 
advanced_1381_p=\ The conversion itself is done internally via <code>'script to'</code> and <code>'runscript from'</code>. After the conversion process, the files will be renamed from 
advanced_1382_code=dbName.data.db
advanced_1383_li=\ to <code>dbName.data.db.backup</code> 
advanced_1384_code=dbName.index.db
advanced_1385_li=\ to <code>dbName.index.db.backup</code> 
advanced_1386_p=\ by default. Also, the temporary script will be written to the database directory instead of a temporary directory. Both defaults can be customized via 
advanced_1387_code=org.h2.upgrade.DbUpgrade.setDeleteOldDb(boolean)
advanced_1388_code=org.h2.upgrade.DbUpgrade.setScriptInTmpDir(boolean)
advanced_1389_p=\ prior opening a database connection. 
advanced_1390_p=\ Since version 1.2.140 it is possible to let the old h2 classes (v 1.2.128) connect to the database. The automatic upgrade .jar file must be present, and the URL must start with <code>jdbc\:h2v1_1\:</code> (the JDBC driver class is <code>org.h2.upgrade.v1_1.Driver</code>). If the database should automatically connect using the old version if a database with the old format exists (without upgrade), and use the new version otherwise, then append <code>;NO_UPGRADE\=TRUE</code> to the database URL. Please note the old driver did not process the system property <code>"h2.baseDir"</code> correctly, so that using this setting is not supported when upgrading. 
advanced_1391_h2=Java Objects Serialization
advanced_1392_p=\ Java objects serialization is enabled by default for columns of type <code>OTHER</code>, using standard Java serialization/deserialization semantics. 
advanced_1393_p=\ To disable this feature set the system property <code>h2.serializeJavaObject\=false</code> (default\: true). 
advanced_1394_p=\ Serialization and deserialization of java objects is customizable both at system level and at database level providing a <a href\="../javadoc/org/h2/api/JavaObjectSerializer.html">JavaObjectSerializer</a> implementation\: 
advanced_1395_li=\ At system level set the system property <code>h2.javaObjectSerializer</code> with the Fully Qualified Name of the <code>JavaObjectSerializer</code> interface implementation. It will be used over the entire JVM session to (de)serialize java objects being stored in column of type OTHER. Example <code>h2.javaObjectSerializer\=com.acme.SerializerClassName</code>. 
advanced_1396_li=\ At database level execute the SQL statement <code>SET JAVA_OBJECT_SERIALIZER 'com.acme.SerializerClassName'</code> or append <code>;JAVA_OBJECT_SERIALIZER\='com.acme.SerializerClassName'</code> to the database URL\: <code>jdbc\:h2\:~/test;JAVA_OBJECT_SERIALIZER\='com.acme.SerializerClassName'</code>. 
advanced_1397_p=\ Please note that this SQL statement can only be executed before any tables are defined. 
advanced_1398_h2=Limits and Limitations
advanced_1399_p=\ This database has the following known limitations\: 
advanced_1400_li=Database file size limit\: 4 TB (using the default page size of 2 KB) or higher (when using a larger page size). This limit is including CLOB and BLOB data. 
advanced_1401_li=The maximum file size for FAT or FAT32 file systems is 4 GB. That means when using FAT or FAT32, the limit is 4 GB for the data. This is the limitation of the file system. The database does provide a workaround for this problem, it is to use the file name prefix <code>split\:</code>. In that case files are split into files of 1 GB by default. An example database URL is\: <code>jdbc\:h2\:split\:~/test</code>. 
advanced_1402_li=The maximum number of rows per table is 2^64. 
advanced_1403_li=Main memory requirements\: The larger the database, the more main memory is required. With the current storage mechanism (the page store), the minimum main memory required is around 1 MB for each 8 GB database file size. 
advanced_1404_li=Limit on the complexity of SQL statements. Statements of the following form will result in a stack overflow exception\: 
advanced_1405_li=There is no limit for the following entities, except the memory and storage capacity\: maximum identifier length (table name, column name, and so on); maximum number of tables, columns, indexes, triggers, and other database objects; maximum statement length, number of parameters per statement, tables per statement, expressions in order by, group by, having, and so on; maximum rows per query; maximum columns per table, columns per index, indexes per table, lob columns per table, and so on; maximum row length, index row length, select row length; maximum length of a varchar column, decimal column, literal in a statement. 
advanced_1406_li=Querying from the metadata tables is slow if there are many tables (thousands). 
advanced_1407_li=For limitations on data types, see the documentation of the respective Java data type or the data type documentation of this database. 
advanced_1408_h2=Glossary and Links
advanced_1409_th=Term
advanced_1410_th=Description
advanced_1411_td=AES-128
advanced_1412_td=A block encryption algorithm. See also\: <a href\="http\://en.wikipedia.org/wiki/Advanced_Encryption_Standard">Wikipedia\: AES</a>
advanced_1413_td=Birthday Paradox
advanced_1414_td=Describes the higher than expected probability that two persons in a room have the same birthday. Also valid for randomly generated UUIDs. See also\: <a href\="http\://en.wikipedia.org/wiki/Birthday_paradox">Wikipedia\: Birthday Paradox</a>
advanced_1415_td=Digest
advanced_1416_td=Protocol to protect a password (but not to protect data). See also\: <a href\="http\://www.faqs.org/rfcs/rfc2617.html">RFC 2617\: HTTP Digest Access Authentication</a>
advanced_1417_td=GCJ
advanced_1418_td=Compiler for Java. <a href\="http\://gcc.gnu.org/java">GNU Compiler for the Java</a> and <a href\="http\://www.dobysoft.com/products/nativej">NativeJ (commercial)</a>
advanced_1419_td=HTTPS
advanced_1420_td=A protocol to provide security to HTTP connections. See also\: <a href\="http\://www.ietf.org/rfc/rfc2818.txt">RFC 2818\: HTTP Over TLS</a>
advanced_1421_td=Modes of Operation
advanced_1422_a=Wikipedia\: Block cipher modes of operation
advanced_1423_td=Salt
advanced_1424_td=Random number to increase the security of passwords. See also\: <a href\="http\://en.wikipedia.org/wiki/Key_derivation_function">Wikipedia\: Key derivation function</a>
advanced_1425_td=SHA-256
advanced_1426_td=A cryptographic one-way hash function. See also\: <a href\="http\://en.wikipedia.org/wiki/SHA_family">Wikipedia\: SHA hash functions</a>
advanced_1427_td=SQL Injection
advanced_1428_td=A security vulnerability where an application embeds SQL statements or expressions in user input. See also\: <a href\="http\://en.wikipedia.org/wiki/SQL_injection">Wikipedia\: SQL Injection</a>
advanced_1429_td=Watermark Attack
advanced_1430_td=Security problem of certain encryption programs where the existence of certain data can be proven without decrypting. For more information, search in the internet for 'watermark attack cryptoloop'
advanced_1431_td=SSL/TLS
advanced_1432_td=Secure Sockets Layer / Transport Layer Security. See also\: <a href\="http\://java.sun.com/products/jsse/">Java Secure Socket Extension (JSSE)</a>
architecture_1000_h1=Architecture
architecture_1001_a=\ Introduction
architecture_1002_a=\ Top-down overview
architecture_1003_a=\ JDBC driver
architecture_1004_a=\ Connection/session management
architecture_1005_a=\ Command execution and planning
architecture_1006_a=\ Table/index/constraints
architecture_1007_a=\ Undo log, redo log, and transactions layer
architecture_1008_a=\ B-tree engine and page-based storage allocation
architecture_1009_a=\ Filesystem abstraction
architecture_1010_h2=Introduction
architecture_1011_p=\ H2 implements an embedded and standalone ANSI-SQL89 compliant SQL engine on top of a B-tree based disk store. 
architecture_1012_p=\ As of October 2013, Thomas is still working on our next-generation storage engine called MVStore. This will in time replace the B-tree based storage engine. 
architecture_1013_h2=Top-down Overview
architecture_1014_p=\ Working from the top down, the layers look like this\: 
architecture_1015_li=JDBC driver. 
architecture_1016_li=Connection/session management. 
architecture_1017_li=SQL Parser. 
architecture_1018_li=Command execution and planning. 
architecture_1019_li=Table/Index/Constraints. 
architecture_1020_li=Undo log, redo log, and transactions layer. 
architecture_1021_li=B-tree engine and page-based storage allocation. 
architecture_1022_li=Filesystem abstraction. 
architecture_1023_h2=JDBC Driver
architecture_1024_p=\ The JDBC driver implementation lives in <code>org.h2.jdbc, org.h2.jdbcx</code> 
architecture_1025_h2=Connection/session management
architecture_1026_p=\ The primary classes of interest are\: 
architecture_1027_th=Package
architecture_1028_th=Description
architecture_1029_td=org.h2.engine.Database
architecture_1030_td=the root/global class
architecture_1031_td=org.h2.engine.SessionInterface
architecture_1032_td=abstracts over the differences between embedded and remote sessions
architecture_1033_td=org.h2.engine.Session
architecture_1034_td=local/embedded session
architecture_1035_td=org.h2.engine.SessionRemote
architecture_1036_td=remote session
architecture_1037_h2=Parser
architecture_1038_p=\ The parser lives in <code>org.h2.command.Parser</code>. It uses a straightforward recursive-descent design. 
architecture_1039_p=\ See Wikipedia <a href\="http\://en.wikipedia.org/wiki/Recursive_descent_parser">Recursive-descent parser</a> page. 
architecture_1040_h2=Command execution and planning
architecture_1041_p=\ Unlike other databases, we do not have an intermediate step where we generate some kind of IR (intermediate representation) of the query. The parser class directly generates a command execution object. Then we run some optimisation steps over the command to possibly generate a more efficient command. The primary packages of interest are\: 
architecture_1042_th=Package
architecture_1043_th=Description
architecture_1044_td=org.h2.command.ddl
architecture_1045_td=Commands that modify schema data structures
architecture_1046_td=org.h2.command.dml
architecture_1047_td=Commands that modify data
architecture_1048_h2=Table/Index/Constraints
architecture_1049_p=\ One thing to note here is that indexes are simply stored as special kinds of tables. 
architecture_1050_p=\ The primary packages of interest are\: 
architecture_1051_th=Package
architecture_1052_th=Description
architecture_1053_td=org.h2.table
architecture_1054_td=Implementations of different kinds of tables
architecture_1055_td=org.h2.index
architecture_1056_td=Implementations of different kinds of indices
architecture_1057_h2=Undo log, redo log, and transactions layer
architecture_1058_p=\ We have a transaction log, which is shared among all sessions. See also http\://en.wikipedia.org/wiki/Transaction_log http\://h2database.com/html/grammar.html\#set_log 
architecture_1059_p=\ We also have an undo log, which is per session, to undo an operation (an update that fails for example) and to rollback a transaction. Theoretically, the transaction log could be used, but for simplicity, H2 currently uses it's own "list of operations" (usually in-memory). 
architecture_1060_p=\ With the MVStore, this is no longer needed (just the transaction log). 
architecture_1061_h2=B-tree engine and page-based storage allocation.
architecture_1062_p=\ The primary package of interest is <code>org.h2.store</code>. 
architecture_1063_p=\ This implements a storage mechanism which allocates pages of storage (typically 2k in size) and also implements a b-tree over those pages to allow fast retrieval and update. 
architecture_1064_h2=Filesystem abstraction.
architecture_1065_p=\ The primary class of interest is <code>org.h2.store.FileStore</code>. 
architecture_1066_p=\ This implements an abstraction of a random-access file. This allows the higher layers to treat in-memory vs. on-disk vs. zip-file databases the same. 
build_1000_h1=Build
build_1001_a=\ Portability
build_1002_a=\ Environment
build_1003_a=\ Building the Software
build_1004_a=\ Build Targets
build_1005_a=\ Using Maven 2
build_1006_a=\ Using Eclipse
build_1007_a=\ Translating
build_1008_a=\ Providing Patches
build_1009_a=\ Reporting Problems or Requests
build_1010_a=\ Automated Build
build_1011_a=\ Generating Railroad Diagrams
build_1012_h2=Portability
build_1013_p=\ This database is written in Java and therefore works on many platforms. It can also be compiled to a native executable using GCJ. 
build_1014_h2=Environment
build_1015_p=\ To run this database, a Java Runtime Environment (JRE) version 1.6 or higher is required. 
build_1016_p=\ To create the database executables, the following software stack was used. To use this database, it is not required to install this software however. 
build_1017_li=Mac OS X and Windows 
build_1018_a=Sun JDK Version 1.6 and 1.7
build_1019_a=Eclipse
build_1020_li=Eclipse Plugins\: <a href\="http\://subclipse.tigris.org">Subclipse</a>, <a href\="http\://eclipse-cs.sourceforge.net">Eclipse Checkstyle Plug-in</a>, <a href\="http\://www.eclemma.org">EclEmma Java Code Coverage</a> 
build_1021_a=Emma Java Code Coverage
build_1022_a=Mozilla Firefox
build_1023_a=OpenOffice
build_1024_a=NSIS
build_1025_li=\ (Nullsoft Scriptable Install System) 
build_1026_a=Maven
build_1027_h2=Building the Software
build_1028_p=\ You need to install a JDK, for example the Sun JDK version 1.6 or 1.7. Ensure that Java binary directory is included in the <code>PATH</code> environment variable, and that the environment variable <code>JAVA_HOME</code> points to your Java installation. On the command line, go to the directory <code>h2</code> and execute the following command\: 
build_1029_p=\ For Linux and OS X, use <code>./build.sh</code> instead of <code>build</code>. 
build_1030_p=\ You will get a list of targets. If you want to build the <code>jar</code> file, execute (Windows)\: 
build_1031_p=\ To run the build tool in shell mode, use the command line option <code>-</code> as in <code>./build.sh -</code>. 
build_1032_h3=Switching the Source Code
build_1033_p=\ The source code uses Java 1.6 features. To switch the source code to the installed version of Java, run\: 
build_1034_h2=Build Targets
build_1035_p=\ The build system can generate smaller jar files as well. The following targets are currently supported\: 
build_1036_code=jarClient
build_1037_li=\ creates the file <code>h2client.jar</code>. This only contains the JDBC client. 
build_1038_code=jarSmall
build_1039_li=\ creates the file <code>h2small.jar</code>. This only contains the embedded database. Debug information is disabled. 
build_1040_code=jarJaqu
build_1041_li=\ creates the file <code>h2jaqu.jar</code>. This only contains the JaQu (Java Query) implementation. All other jar files do not include JaQu. 
build_1042_code=javadocImpl
build_1043_li=\ creates the Javadocs of the implementation. 
build_1044_p=\ To create the file <code>h2client.jar</code>, go to the directory <code>h2</code> and execute the following command\: 
build_1045_h3=Using Lucene 2 / 3
build_1046_p=\ Both Apache Lucene 2 and Lucene 3 are supported. Currently Apache Lucene version 2.x is used by default for H2 version 1.2.x, and Lucene version 3.x is used by default for H2 version 1.3.x. To use a different version of Lucene when compiling, it needs to be specified as follows\: 
build_1047_h2=Using Maven 2
build_1048_h3=Using a Central Repository
build_1049_p=\ You can include the database in your Maven 2 project as a dependency. Example\: 
build_1050_p=\ New versions of this database are first uploaded to http\://hsql.sourceforge.net/m2-repo/ and then automatically synchronized with the main <a href\="http\://repo2.maven.org/maven2/com/h2database/h2/">Maven repository</a>; however after a new release it may take a few hours before they are available there. 
build_1051_h3=Maven Plugin to Start and Stop the TCP Server
build_1052_p=\ A Maven plugin to start and stop the H2 TCP server is available from <a href\="https\://github.com/ljnelson/h2-maven-plugin">Laird Nelson at GitHub</a>. To start the H2 server, use\: 
build_1053_p=\ To stop the H2 server, use\: 
build_1054_h3=Using Snapshot Version
build_1055_p=\ To build a <code>h2-*-SNAPSHOT.jar</code> file and upload it the to the local Maven 2 repository, execute the following command\: 
build_1056_p=\ Afterwards, you can include the database in your Maven 2 project as a dependency\: 
build_1057_h2=Using Eclipse
build_1058_p=\ To create an Eclipse project for H2, use the following steps\: 
build_1059_li=Install Subversion and <a href\="http\://www.eclipse.org">Eclipse</a>. 
build_1060_li=Get the H2 source code from the Subversion repository\:
build_1061_code=svn checkout http\://h2database.googlecode.com/svn/trunk h2database-read-only
build_1062_li=Download all dependencies (Windows)\:
build_1063_code=build.bat download
build_1064_li=In Eclipse, create a new Java project from existing source code\: <code>File, New, Project, Java Project, Create project from existing source</code>. 
build_1065_li=Select the <code>h2</code> folder, click <code>Next</code> and <code>Finish</code>. 
build_1066_li=To resolve <code>com.sun.javadoc</code> import statements, you may need to manually add the file <code>&lt;java.home&gt;/../lib/tools.jar</code> to the build path. 
build_1067_h2=Translating
build_1068_p=\ The translation of this software is split into the following parts\: 
build_1069_li=H2 Console\: <code>src/main/org/h2/server/web/res/_text_*.prop</code> 
build_1070_li=Error messages\: <code>src/main/org/h2/res/_messages_*.prop</code> 
build_1071_p=\ To translate the H2 Console, start it and select Preferences / Translate. After you are done, send the translated <code>*.prop</code> file to the Google Group. The web site is currently translated using Google. 
build_1072_h2=Providing Patches
build_1073_p=\ If you like to provide patches, please consider the following guidelines to simplify merging them\: 
build_1074_li=Only use Java 6 features (do not use Java 7) (see <a href\="\#environment">Environment</a>). 
build_1075_li=Follow the coding style used in the project, and use Checkstyle (see above) to verify. For example, do not use tabs (use spaces instead). The checkstyle configuration is in <code>src/installer/checkstyle.xml</code>. 
build_1076_li=A template of the Eclipse settings are in <code>src/installer/eclipse.settings/*</code>. If you want to use them, you need to copy them to the <code>.settings</code> directory. The formatting options (<code>eclipseCodeStyle</code>) are also included. 
build_1077_li=Please provide test cases and integrate them into the test suite. For Java level tests, see <code>src/test/org/h2/test/TestAll.java</code>. For SQL level tests, see <code>src/test/org/h2/test/test.in.txt</code> or <code>testSimple.in.txt</code>. 
build_1078_li=The test cases should cover at least 90% of the changed and new code; use a code coverage tool to verify that (see above). or use the build target <code>coverage</code>. 
build_1079_li=Verify that you did not break other features\: run the test cases by executing <code>build test</code>. 
build_1080_li=Provide end user documentation if required (<code>src/docsrc/html/*</code>). 
build_1081_li=Document grammar changes in <code>src/docsrc/help/help.csv</code> 
build_1082_li=Provide a change log entry (<code>src/docsrc/html/changelog.html</code>). 
build_1083_li=Verify the spelling using <code>build spellcheck</code>. If required add the new words to <code>src/tools/org/h2/build/doc/dictionary.txt</code>. 
build_1084_li=Run <code>src/installer/buildRelease</code> to find and fix formatting errors. 
build_1085_li=Verify the formatting using <code>build docs</code> and <code>build javadoc</code>. 
build_1086_li=Submit patches as <code>.patch</code> files (compressed if big). To create a patch using Eclipse, use Team / Create Patch. 
build_1087_p=\ For legal reasons, patches need to be public in the form of an email to the <a href\="http\://groups.google.com/group/h2-database">group</a>, or in the form of an <a href\="http\://code.google.com/p/h2database/issues/list">issue report or attachment</a>. Significant contributions need to include the following statement\: 
build_1088_p=\ "I wrote the code, it's mine, and I'm contributing it to H2 for distribution multiple-licensed under the H2 License, version 1.0, and under the Eclipse Public License, version 1.0 (http\://h2database.com/html/license.html)." 
build_1089_h2=Reporting Problems or Requests
build_1090_p=\ Please consider the following checklist if you have a question, want to report a problem, or if you have a feature request\: 
build_1091_li=For bug reports, please provide a <a href\="http\://sscce.org/">short, self contained, correct (compilable), example</a> of the problem. 
build_1092_li=Feature requests are always welcome, even if the feature is already on the <a href\="roadmap.html">roadmap</a>. Your mail will help prioritize feature requests. If you urgently need a feature, consider <a href\="\#providing_patches">providing a patch</a>. 
build_1093_li=Before posting problems, check the <a href\="faq.html">FAQ</a> and do a <a href\="http\://google.com">Google search</a>. 
build_1094_li=When got an unexpected exception, please try the <a href\="sourceError.html">Error Analyzer tool</a>. If this doesn't help, please report the problem, including the complete error message and stack trace, and the root cause stack trace(s). 
build_1095_li=When sending source code, please use a public web clipboard such as <a href\="http\://pastebin.com">Pastebin</a>, <a href\="http\://cl1p.net">Cl1p</a>, or <a href\="http\://www.mysticpaste.com/new">Mystic Paste</a> to avoid formatting problems. Please keep test cases as simple and short as possible, but so that the problem can still be reproduced. As a template, use\: <a href\="http\://h2database.googlecode.com/svn/trunk/h2/src/test/org/h2/samples/HelloWorld.java">HelloWorld.java</a>. Method that simply call other methods should be avoided, as well as unnecessary exception handling. Please use the JDBC API and no external tools or libraries. The test should include all required initialization code, and should be started with the main method. 
build_1096_li=For large attachments, use a public temporary storage such as <a href\="http\://rapidshare.com">Rapidshare</a>. 
build_1097_li=Google Group versus issue tracking\: Use the <a href\="http\://groups.google.com/group/h2-database">Google Group</a> for questions or if you are not sure it's a bug. If you are sure it's a bug, you can create an <a href\="http\://code.google.com/p/h2database/issues/list">issue</a>, but you don't need to (sending an email to the group is enough). Please note that only few people monitor the issue tracking system. 
build_1098_li=For out-of-memory problems, please analyze the problem yourself first, for example using the command line option <code>-XX\:+HeapDumpOnOutOfMemoryError</code> (to create a heap dump file on out of memory) and a memory analysis tool such as the <a href\="http\://www.eclipse.org/mat">Eclipse Memory Analyzer (MAT)</a>. 
build_1099_li=It may take a few days to get an answers. Please do not double post. 
build_1100_h2=Automated Build
build_1101_p=\ This build process is automated and runs regularly. The build process includes running the tests and code coverage, using the command line <code>./build.sh clean jar coverage -Dh2.ftpPassword\=... uploadBuild</code>. The last results are available here\: 
build_1102_a=Test Output
build_1103_a=Code Coverage Summary
build_1104_a=Code Coverage Details (download, 1.3 MB)
build_1105_a=Build Newsfeed
build_1106_a=Latest Jar File (download, 1 MB)
build_1107_h2=Generating Railroad Diagrams
build_1108_p=\ The railroad diagrams of the <a href\="grammar.html">SQL grammar</a> are HTML, formatted as nested tables. The diagrams are generated as follows\: 
build_1109_li=The BNF parser (<code>org.h2.bnf.Bnf</code>) reads and parses the BNF from the file <code>help.csv</code>. 
build_1110_li=The page parser (<code>org.h2.server.web.PageParser</code>) reads the template HTML file and fills in the diagrams. 
build_1111_li=The rail images (one straight, four junctions, two turns) are generated using a simple Java application. 
build_1112_p=\ To generate railroad diagrams for other grammars, see the package <code>org.h2.jcr</code>. This package is used to generate the SQL-2 railroad diagrams for the JCR 2.0 specification. 
changelog_1000_h1=Change Log
changelog_1001_h2=Next Version (unreleased)
changelog_1002_h2=Version 1.4.178 Beta (2014-05-02)
changelog_1003_li=Issue 559\: Make dependency on org.osgi.service.jdbc optional. 
changelog_1004_li=Improve error message when the user specifies an unsupported combination of database settings. 
changelog_1005_li=MVStore\: in the multi-threaded mode, NullPointerException and other exceptions could occur. 
changelog_1006_li=MVStore\: some database file could not be compacted due to a bug in the bookkeeping of the fill rate. Also, database file were compacted quite slowly. This has been improved; but more changes in this area are expected. 
changelog_1007_li=MVStore\: support for volatile maps (that don't store changes). 
changelog_1008_li=MVStore mode\: in-memory databases now also use the MVStore. 
changelog_1009_li=In server mode, appending ";autocommit\=false" to the database URL was working, but the return value of Connection.getAutoCommit() was wrong. 
changelog_1010_li=Issue 561\: OSGi\: the import package declaration of org.h2 excluded version 1.4. 
changelog_1011_li=Issue 558\: with the MVStore, a NullPointerException could occur when using LOBs at session commit (LobStorageMap.removeLob). 
changelog_1012_li=Remove the "h2.MAX_MEMORY_ROWS_DISTINCT" system property to reduce confusion. We already have the MAX_MEMORY_ROWS setting which does a very similar thing, and is better documented. 
changelog_1013_li=Issue 554\: Web Console in an IFrame was not fully supported. 
changelog_1014_h2=Version 1.4.177 Beta (2014-04-12)
changelog_1015_li=By default, the MV_STORE option is enabled, so it is using the new MVStore storage. The MVCC setting is by default set to the same values as the MV_STORE setting, so it is also enabled by default. For testing, both settings can be disabled by appending ";MV_STORE\=FALSE" and/or ";MVCC\=FALSE" to the database URL. 
changelog_1016_li=The file locking method 'serialized' is no longer supported. This mode might return in a future version, however this is not clear right now. A new implementation and new tests would be needed. 
changelog_1017_li=Enable the new storage format for dates (system property "h2.storeLocalTime"). For the MVStore mode, this is always enabled, but with version 1.4 this is even enabled in the PageStore mode. 
changelog_1018_li=Implicit relative paths are disabled (system property "h2.implicitRelativePath"), so that the database URL jdbc\:h2\:test now needs to be written as jdbc\:h2\:./test. 
changelog_1019_li="select ... fetch first 1 row only" is supported with the regular mode. This was disabled so far because "fetch" is now a keyword. See also Mode.supportOffsetFetch. 
changelog_1020_li=Byte arrays are now sorted in unsigned mode (x'99' is larger than x'09'). (System property "h2.sortBinaryUnsigned", Mode.binaryUnsigned, setting "binary_collation"). 
changelog_1021_li=Csv.getInstance will be removed in future versions of 1.4. Use the public constructor instead. 
changelog_1022_li=Remove support for the limited old-style outer join syntax using "(+)". Use "outer join" instead. System property "h2.oldStyleOuterJoin". 
changelog_1023_li=Support the data type "DATETIME2" as an alias for "DATETIME", for MS SQL Server compatibility. 
changelog_1024_li=Add Oracle-compatible TRANSLATE function, patch by Eric Chatellier. 
changelog_1025_h2=Version 1.3.176 (2014-04-05)
changelog_1026_li=The file locking method 'serialized' is no longer documented, as it will not be available in version 1.4. 
changelog_1027_li=The static method Csv.getInstance() was removed. Use the public constructor instead. 
changelog_1028_li=The default user name for the Script, RunScript, Shell, and CreateCluster tools are no longer "sa" but an empty string. 
changelog_1029_li=The stack trace of the exception "The object is already closed" is no longer logged by default. 
changelog_1030_li=If a value of a result set was itself a result set, the result could only be read once. 
changelog_1031_li=Column constraints are also visible in views (patch from Nicolas Fortin for H2GIS). 
changelog_1032_li=Granting a additional right to a role that already had a right for that table was not working. 
changelog_1033_li=Spatial index\: a few bugs have been fixed (using spatial constraints in views, transferring geometry objects over TCP/IP, the returned geometry object is copied when needed). 
changelog_1034_li=Issue 551\: the datatype documentation was incorrect (found by Bernd Eckenfels). 
changelog_1035_li=Issue 368\: ON DUPLICATE KEY UPDATE did not work for multi-row inserts. Test case from Angus Macdonald. 
changelog_1036_li=OSGi\: the package javax.tools is now imported (as an optional). 
changelog_1037_li=H2 Console\: auto-complete is now disabled by default, but there is a hot-key (Ctrl+Space). 
changelog_1038_li=H2 Console\: auto-complete did not work with multi-line statements. 
changelog_1039_li=CLOB and BLOB data was not immediately removed after a rollback. 
changelog_1040_li=There is a new Aggregate API that supports the internal H2 data types (GEOMETRY for example). Thanks a lot to Nicolas Fortin for the patch\! 
changelog_1041_li=Referential integrity constraints sometimes used the wrong index, such that updating a row in the referenced table incorrectly failed with a constraint violation. 
changelog_1042_li=The Polish translation was completed and corrected by Wojtek Jurczyk. Thanks a lot\! 
changelog_1043_li=Issue 545\: Unnecessary duplicate code was removed. 
changelog_1044_li=The profiler tool can now process files with full thread dumps. 
changelog_1045_li=MVStore\: the file format was changed slightly. 
changelog_1046_li=MVStore mode\: the CLOB and BLOB storage was re-implemented and is now much faster than with the PageStore (which is still the default storage). 
changelog_1047_li=MVStore mode\: creating indexes is now much faster (in many cases faster than with the default PageStore). 
changelog_1048_li=Various bugs in the MVStore storage and have been fixed, including a bug in the R-tree implementation. The database could get corrupt if there were transient IO exceptions while storing. 
changelog_1049_li=The method org.h2.expression.Function.getCost could throw a NullPointException. 
changelog_1050_li=Storing LOBs in separate files (outside of the main database file) is no longer supported for new databases. 
changelog_1051_li=Lucene 2 is no longer supported. 
changelog_1052_li=Fix bug in calculating default MIN and MAX values for SEQUENCE. 
changelog_1053_li=Fix bug in performing IN queries with multiple values when IGNORECASE\=TRUE 
changelog_1054_li=Add entry-point to org.h2.tools.Shell so it can be called from inside an application. patch by Thomas Gillet. 
changelog_1055_li=Fix bug that prevented the PgServer from being stopped and started multiple times. 
changelog_1056_li=Support some more DDL syntax for MySQL, patch from Peter Jentsch. 
changelog_1057_li=Issue 548\: TO_CHAR does not format MM and DD correctly when the month or day of the month is 1 digit, patch from "the.tucc" 
changelog_1058_li=Fix bug in varargs support in ALIAS's, patch from Nicolas Fortin 
changelog_1059_h2=Version 1.3.175 (2014-01-18)
changelog_1060_li=EXPLAIN was incorrect for queries with "ANY" or "SOME" conditions. 
changelog_1061_li=CallableStatement with "out" parameters\: running the same statement twice could result in an exception ("parameter not set"). 
changelog_1062_li=Union queries\: duplicate rows could be returned if the sub-queries contained "order by". 
changelog_1063_li=The GEOMETRY data type now works for user defined functions that return a result set. 
changelog_1064_li=PostgreSQL compatibility\: the PgServer was not working properly when the setting database_to_upper was set to false. 
changelog_1065_li=JdbcDataSource\: the methods setUrl and getUrl where added as aliases for setURL and getURL. This should solve problems with the HikariCP (Hikari connection pool). 
changelog_1066_li=Issue 537\: H2 Console\: when loading the schema, incorrect JDBC calls where issued, which caused the exception "Column PRECISION not found". 
changelog_1067_li=Improved Geometry processing (issue 535). 
changelog_1068_li=The collation can now be set in the database URL, even if there are data tables, if the collection is the same as the current collation. 
changelog_1069_li=Improved Oracle compatibility for CASE WHEN and DECODE. 
changelog_1070_li=The statement "drop all objects" did not work if a table depends on a view via a constraint. 
changelog_1071_li=Subqueries or views with "order by" an alias expression could not be executed due to a regression introduced in version 1.3.174. 
changelog_1072_li=Issue 73\: MySQL compatibility\: support REPLACE, patch by Cemo Koc. 
changelog_1073_li=The spatial index now works in MVCC mode when using the MVStore storage. 
changelog_1074_li=MVStore\: concurrency problems have been fixed. The API has been simplified. 
changelog_1075_li=Improve error message when dropping an index that belongs to a constraint, specify constraint in error message. 
changelog_1076_li=Issue 518\: java.sql.Connection.commit() freezes after LOB modification with EXCLUSIVE connection 
changelog_1077_li=Issue 517\: Create or replace view statement has no effect on the others already existing JDBC connection 
changelog_1078_li=Support 123L syntax as in Java; example\: SELECT (2000000000L*2). 
changelog_1079_li=Issue 520\: Add support for sequence max value, min value and cycle, patch by Daniel Gredler. 
changelog_1080_li=Issue 521\: ScriptReader should implement Closeable 
changelog_1081_li=Issue 524\: RunScript.execute does not close its Statement, patch from Gaul. 
changelog_1082_li=Add support for DB2 "WITH UR" clause, patch from litailang 
changelog_1083_li=Added support for ON DUPLICATE KEY UPDATE like MySQL with the values() function to update with the value that was to be inserted. Patch from Jean-Francois Noel. 
changelog_1084_li=Issue 522\: Treat empty strings like NULL in Oracle compatibility mode, patch by Daniel Gredler. 
changelog_1085_li=Issue 527\: Oracle compatibility mode\: incorrect scale behavior, patch by Daniel Gredler. 
changelog_1086_li=Slightly reduce the memory cost of View metadata. 
changelog_1087_li=Extend support of "GRANT ALTER ANY SCHEMA TO &lt;user&gt;" to allow grantee ability to manipulate tables 
changelog_1088_li=Issue 532\: Javadoc for ErrorCode.ROLES_AND_RIGHT_CANNOT_BE_MIXED looks wrong 
changelog_1089_li=Issue 528\: Add Oracle-compatible TO_CHAR function, patch by Daniel Gredler. 
changelog_1090_li=Issue 534\: CREATE ALIAS NOCACHE, Patch by Nicolas Fortin 
changelog_1091_li=Fix an issue with storing Unicode surrogate pairs in CLOB columns. 
changelog_1092_li=H2 console\: add SHIFT+ENTER "run selected" functionality 
changelog_1093_li=Fix bug in DB2 syntax "select * from test with ur", patch from litailang 
changelog_1094_li=Fix bug in DROP ALL OBJECTS when dealing with inter-schema dependencies. 
changelog_1095_h2=Version 1.3.174 (2013-10-19)
changelog_1096_li=LIRS cache\: bugfix for caches that only contain non-resident entries. 
changelog_1097_li=For in-memory databases, queries with a "group by" column that is also a hash index threw a RuntimeException. 
changelog_1098_li=Improved error message for some syntax errors. 
changelog_1099_li=File system abstraction\: if used directly, some file systems did not work correctly with spliced byte buffers (the database engine doesn't use those). 
changelog_1100_li=To use the MVStore storage engine (which is still work in progress), append ";mv_store\=true" to the database URL. Using the MVTableEngine when creating the table is no longer recommended. 
changelog_1101_li=To compile user defined functions, the javax.tools.JavaCompiler is now used if available, and no temporary files are created. This should solve problems when multiple H2 database concurrently compile the same user defined functions. To disable, system the system property "h2.javaSystemCompiler" to false. 
changelog_1102_li=Concurrently creating function aliases in different databases could result in the exception "javac\: file not found". 
changelog_1103_li=The function "regexp_replace" threw the wrong kind of exception if the replacement string was invalid. 
changelog_1104_li=A checkpoint is now done every MAX_LOG_SIZE / 2 instead of every MAX_LOG_SIZE, so that the transaction log doesn't grow as large. 
changelog_1105_li=MVStore table engine\: new setting "retention_time" to configure the time to retain old data. The default is 45 seconds. 
changelog_1106_li=The method TableEngine.createTable() now returns a Table object. 
changelog_1107_li=For read-only databases, for the trace level "debug", the trace info is written to the temp directory. 
changelog_1108_li=Closing the file lock will now wait until the background thread is stopped. 
changelog_1109_li=In version 1.3.172, a performance regression was introduced when fixing the issue 389 (when there is a multi-column primary key, H2 does not seem to always pick the right index). This was related to boosting an index that matches the "order by" column list (the wrong index was used in some cases). 
changelog_1110_li=Improved spatial index and data type. 
changelog_1111_li=Issue 467\: OSGi Class Loader (ability to create reference to class in other ClassLoader, for example in another OSGi bundle). 
changelog_1112_li=Queries "group by" that contain a subquery with an aggregate function returned the wrong result in some cases. 
changelog_1113_li=Fix bug in unique and non-unique hash indexes which manifested as incorrect results when the search key was a different cardinal type from the table index key. e.g. where the one was INT and the other was LONG 
changelog_1114_li=Bug\: Changes to the database structure did not result in the Session query cache being invalidated. 
changelog_1115_li=New feature from Davide Cavestro - allow using custom Java object serialization engines on a per-DB basis. 
changelog_1116_li=When running the Recover tool on very large (&gt;6G) databases, some statistics were reported with negative numbers. 
changelog_1117_li=Add a CONTAINS_UNCOMMITTED column to the SESSIONS metadata table, to allow detecting when rogue sessions are creating large transactions. 
changelog_1118_li=Some small fixes to the GEOMETRY support, patches by Nicolas Fortin. 
changelog_1119_li=The BNF tool and the autocomplete feature are exported in OSGi, which makes it possible for smart editors to do autocomplete. Patch from Nicolas Fortin. 
changelog_1120_li=Fix DROP ALL OBJECTS and DROP SCHEMA in the presence of tables with computed column dependencies. 
changelog_1121_li=Session-temporary LOB's could sometimes accumulate, increasing the size of the DB file until shutdown. Now they are cleared out at every commit. 
changelog_1122_li=There was a bug where a hash index with more than one column would be silently converted to a regular index. It will now throw an exception. 
changelog_1123_li=Query Statistics\: new feature which stores the newest 100 SQL queries executed and their performance data. Useful for tracking down badly performing queries. 
changelog_1124_li=Fix an LOB deadlock between reading and updating LOB columns. 
changelog_1125_li=Support the JDBC DatabaseMetaData\#getClientInfoProperties() method, in the sense of returning an empty result, in order to make WebSphere happy. 
changelog_1126_li=Make Server\#openBrowser respect the $BROWSER environment variable. Add "chromium" to the list of browsers tried. Patch from Felix Kaiser. 
changelog_1127_li=Fix to org.h2.util.ScriptReader when handling unclosed block comments. 
changelog_1128_li=Make org.h2.util.ScriptReader throw a better exception when handling broken scripts which generate extremely large statements. 
changelog_1129_li=Fix bug with ALLOW_LITERALS\=NONE, where the periodic analyze table on insert would throw an exception. A similar problem was fixed in the Console tool. 
changelog_1130_li=Issue 510\: Make org.h2.bnf public for consumption by external projects, patch by Nicolas Fortin 
changelog_1131_li=Issue 509\: Important fix on ValueGeometry, patch by Nicolas Fortin (with some tweaking) Make ValueGeometry\#getDimensionCount more reliable. Add unit test to check for illegal ValueGeometry comparison Add unit test for conversion of Geometry object into Object Add optional export to MANIFEST.MF for JTS Geometry classes Validate that geometry values can be represented in WKB. 
changelog_1132_li=Issue 506\: RFE\: Include Thread.getName() in case of a deadlock 
changelog_1133_li=Adding support for "GRANT ALTER ANY SCHEMA TO &lt;user&gt;", patch by John Yates 
changelog_1134_h2=Version 1.3.173 (2013-07-28)
changelog_1135_li=Support empty statements that just contains a comment. 
changelog_1136_li=Server mode\: if there was an error while reading from a LOB, the session was closed in some cases. 
changelog_1137_li=Issue 463\: Driver name and version are now the same in OsgiDataSourceFactory and JdbcDatabaseMetaData. 
changelog_1138_li=JaQu\: The data type VARCHAR is now (again) used for Strings (no longer TEXT, except when explicitly set). 
changelog_1139_li=For in-memory databases, creating an index on a CLOB or BLOB column is no longer supported. This is to simplify the MVTableEngine. 
changelog_1140_li=New column "information_schema.tables.row_count_estimate". 
changelog_1141_li=Issue 468\: trunc(timestamp) could return the wrong value (+12 hours), and trunc(number) throw a NullPointerException. 
changelog_1142_li=The expression trunc(number) threw a NullPointerException. 
changelog_1143_li=Fixed a deadlock when updating LOB's concurrently. See TestLob.testDeadlock2(). 
changelog_1144_li=Fixed a deadlock related to very large temporary result sets. 
changelog_1145_li=Add "-list" command line option to Shell tool so that result-list-mode can be triggered when reading from a file. 
changelog_1146_li=Issue 474\: H2 MySQL Compatibility code fails to ignore "COMMENT" in CREATE TABLE, patch from Aaron Azeckoski. 
changelog_1147_li=Issue 476\: Broken link in jaqu.html 
changelog_1148_li=Fix potential UTF8 encoding issue in org.h2.store.FileStore, reported by Juerg Spiess. 
changelog_1149_li=Improve error message when check constraint is broken, test case from Gili (cowwoc). 
changelog_1150_li=Improve error message when we have a unique constraint violation, displays the offending key in the error message. 
changelog_1151_li=Issue 478\: Support for "SHOW TRANSACTION ISOLATION LEVEL", patch from Andrew Franklin. 
changelog_1152_li=Issue 475\: PgServer\: add support for CancelRequest, patch from Andrew Franklin. 
changelog_1153_li=Issue 473\: PgServer missing -key option, patch from Andrew Franklin. 
changelog_1154_li=Issue 471\: CREATE VIEW does not check user rights, patch from Andrew Franklin. 
changelog_1155_li=Issue 477\: PgServer binary transmission of query params is unimplemented, patch from Andrew Franklin. 
changelog_1156_li=Issue 479\: Support for SUBSTRING without a FROM condition, patch from Andrew Franklin. 
changelog_1157_li=Issue 472\: PgServer does not work with any recent Postgres JDBC driver, patch from Andrew Franklin. 
changelog_1158_li=Add syntax for passing additional parameters into custom TableEngine implementations. 
changelog_1159_li=Issue 480\: Bugfix post issue 475, 477, patch from Andrew Franklin. 
changelog_1160_li=Issue 481\: Further extensions to PgServer to support better support PG JDBC, patch from Andrew Franklin. 
changelog_1161_li=Add support for spatial datatype GEOMETRY. 
changelog_1162_li=Add support for in-memory spatial index. 
changelog_1163_li=change the PageStore\#changeCount field from an int to a long, to cope with databases with very high transaction rates. 
changelog_1164_li=Fix a NullPointerException when attempting to add foreign key reference to a view. 
changelog_1165_li=Add sufficient ClientInfo support to our javax.sql.Connection implementation to make WebSphere happy. 
changelog_1166_li=Issue 482\: class LobStorageBackend$LobInputStream does not override the method InputStream.available(). 
changelog_1167_li=Fix corruption resulting from a mix of the "WRITE_DELAY\=0" option and "SELECT DISTINCT" queries that don't fit in memory. 
changelog_1168_li=Fix the combination of updating a table which contains an LOB, and reading from the LOB at the same time. Previously it would throw an exception, now it works. 
changelog_1169_li=Issue 484\: In the H2 Console tool, all schemas starting with "INFO" where hidden. Now they are hidden only if the database is not H2. Patch from "mgcodeact"/"cumer d" 
changelog_1170_li=MySQL compatibility, support the "AUTO_INCREMENT\=3" part of the CREATE TABLE statement. 
changelog_1171_li=Issue 486\: MySQL compatibility, support the "DEFAULT CHARSET" part of the CREATE TABLE statement. 
changelog_1172_li=Issue 487\: support the MySQL "SET foreign_key_checks \= 0" command 
changelog_1173_li=Issue 490\: support MySQL "USING BTREE" index declaration 
changelog_1174_li=Issue 485\: Database get corrupted when column is renamed for which check constraint was defined inside create table statement. 
changelog_1175_li=Issue 499\: support MySQL "UNIQUE KEY (ID) USING BTREE" constraint syntax 
changelog_1176_li=Issue 501\: "CREATE TABLE .. WITH" not serialized, patch from nico.devel 
changelog_1177_li=Avoid problems with runtime-compiled ALIAS methods when people have set the JAVA_TOOL_OPTIONS environment variable. 
changelog_1178_h2=Version 1.3.172 (2013-05-25)
changelog_1179_li=Referential integrity\: when adding a referential integrity constraint failed, and if creating the constraint automatically created an index, this index was not removed. 
changelog_1180_li=The auto-analyze feature now only reads 1000 rows per table instead of 10000. 
changelog_1181_li=The optimization for IN(...) queries combined with OR could result in a strange exception of the type "column x must be included in the group by list". 
changelog_1182_li=Issue 454\: Use Charset for type-safety. 
changelog_1183_li=Queries with both LIMIT and OFFSET could throw an IllegalArgumentException. 
changelog_1184_li=MVStore\: multiple issues were fixed\: 460, 461, 462, 464, 466. 
changelog_1185_li=MVStore\: larger stores (multiple GB) are now much faster. 
changelog_1186_li=When using local temporary tables and not dropping them manually before closing the session, and then killing the process could result in a database that couldn't be opened (except when using the recover tool). 
changelog_1187_li=Support TRUNC(timestamp) for improved Oracle compatibility. 
changelog_1188_li=Add support for CREATE TABLE TEST (ID BIGSERIAL) for PostgreSQL compatibility. Patch from Jesse Long. 
changelog_1189_li=Add new collation command SET BINARY_COLLATION UNSIGNED, helps with people testing BINARY columns in MySQL mode. 
changelog_1190_li=Issue 453\: ABBA race conditions in TABLE LINK connection sharing. 
changelog_1191_li=Issue 449\: Postgres Serial data type should not automatically be marked as primary key 
changelog_1192_li=Issue 406\: Support "select h2version()" 
changelog_1193_li=Issue 389\: When there is a multi-column primary key, H2 does not seem to always pick the right index 
changelog_1194_li=Issue 305\: Implement SELECT ... FOR FETCH ONLY 
changelog_1195_li=Issue 274\: Sybase/MSSQLServer compatibility - Add GETDATE and CHARINDEX system functions 
changelog_1196_li=Issue 274\: Sybase/MSSQLServer compatibility - swap parameters of CONVERT function. 
changelog_1197_li=Issue 274\: Sybase/MSSQLServer compatibility - support index clause e.g. "select * from test (index table1_index)" 
changelog_1198_li=Fix bug in Optimizing SELECT * FROM A WHERE X\=1 OR X\=2 OR X\=3 into SELECT * FROM A WHERE X IN (1,2,3) 
changelog_1199_li=Issue 442\: Groovy patch for SourceCompiler (function ALIAS) 
changelog_1200_li=Issue 459\: Improve LOB documentation 
changelog_1201_h2=Version 1.3.171 (2013-03-17)
changelog_1202_li=Security\: the TCP server did not correctly restrict access rights of clients in some cases. This was specially a problem when using the flag "tcpAllowOthers". 
changelog_1203_li=H2 Console\: the session timeout can now be configured using the system property "h2.consoleTimeout". 
changelog_1204_li=Issue 431\: Improved compatibility with MySQL\: support for "ENGINE\=InnoDB charset\=UTF8" when creating a table. 
changelog_1205_li=Issue 249\: Improved compatibility with MySQL in the MySQL mode\: now the methods DatabaseMetaData methods stores*Case*Identifiers return the same as MySQL when using the MySQL mode. 
changelog_1206_li=Issue 434\: H2 Console didn't work in the Chrome browser due to a wrong viewport argument. 
changelog_1207_li=There was a possibility that the .lock.db file was not deleted when the database was closed, which could slow down opening the database. 
changelog_1208_li=The SQL script generated by the "script" command contained inconsistent newlines on Windows. 
changelog_1209_li=When using trace level 4 (SLF4J) in the server mode, a directory "trace.db" and an empty file was created on the client side. This is no longer made. 
changelog_1210_li=Optimize IN(...) queries\: there was a bug in version 1.3.170 if the type of the left hand side didn't match the type of the right hand side. Fixed. 
changelog_1211_li=Optimize IN(...) queries\: there was a bug in version 1.3.170 for comparison of the type "X IN(NULL, NULL)". Fixed. 
changelog_1212_li=Timestamps with timezone that were passed as a string were not always converted correctly. For example "2012-11-06T23\:00\:00.000Z" was converted to "2012-11-06" instead of to "2012-11-07" in the timezone CET. Thanks a lot to Steve Hruda for reporting the problem\! 
changelog_1213_li=New table engine "org.h2.mvstore.db.MVTableEngine" that internally uses the MVStore to persist data. To try it out, append ";DEFAULT_TABLE_ENGINE\=org.h2.mvstore.db.MVTableEngine" to the database URL. This is still very experimental, and many features are not supported yet. The data is stored in a file with the suffix ".mv.db". 
changelog_1214_li=New connection setting "DEFAULT_TABLE_ENGINE" to use a specific table engine if none is set explicitly. This is to simplify testing the MVStore table engine. 
changelog_1215_li=MVStore\: encrypted stores are now supported. Only standardized algorithms are used\: PBKDF2, SHA-256, XTS-AES, AES-128. 
changelog_1216_li=MVStore\: improved API thanks to Simo Tripodi. 
changelog_1217_li=MVStore\: maps can now be renamed. 
changelog_1218_li=MVStore\: store the file header also at the end of each chunk, which results in a further reduced number of write operations. 
changelog_1219_li=MVStore\: a map implementation that supports concurrent operations. 
changelog_1220_li=MVStore\: unified exception handling; the version is included in the messages. 
changelog_1221_li=MVStore\: old data is now retained for 45 seconds by default. 
changelog_1222_li=MVStore\: compress is now disabled by default, and can be enabled on request. 
changelog_1223_li=Support ALTER TABLE ADD ... AFTER. Patch from Andrew Gaul (argaul at gmail.com). Fixes issue 401. 
changelog_1224_li=Improved OSGi support. H2 now registers itself as a DataSourceFactory service. Fixes issue 365. 
changelog_1225_li=Add a DISK_SPACE_USED system function. Fixes issue 270. 
changelog_1226_li=Fix a compile-time ambiguity when compiling with JDK7, thanks to a patch from Lukas Eder. 
changelog_1227_li=Supporting dropping an index for Lucene full-text indexes. 
changelog_1228_li=Optimized performance for SELECT ... ORDER BY X LIMIT Y OFFSET Z queries for in-memory databases using partial sort (by Sergi Vladykin). 
changelog_1229_li=Experimental off-heap memory storage engine "nioMemFS\:" and "nioMemLZF\:", suggestion from Mark Addleman. 
changelog_1230_li=Issue 438\: JdbcDatabaseMetaData.getSchemas() is no longer supported as of 1.3.169. 
changelog_1231_li=MySQL compatibility\: support for ALTER TABLE tableName MODIFY [COLUMN] columnName columnDef. Patch from Ville Koskela. 
changelog_1232_li=Issue 404\: SHOW COLUMNS FROM tableName does not work with ALLOW_LITERALS\=NUMBERS. 
changelog_1233_li=Throw an explicit error to make it clear we don't support the TRIGGER combination of SELECT and FOR EACH ROW. 
changelog_1234_li=Issue 439\: Utils.sortTopN does not handle single-element arrays. 
changelog_1235_h2=Version 1.3.170 (2012-11-30)
changelog_1236_li=Issue 407\: The TriggerAdapter didn't work with CLOB and BLOB columns. 
changelog_1237_li=PostgreSQL compatibility\: support for data types BIGSERIAL and SERIAL as an alias for AUTO_INCREMENT. 
changelog_1238_li=Issue 417\: H2 Console\: the web session timeout didn't work, resulting in a memory leak. This was only a problem if the H2 Console was run for a long time and many sessions were opened. 
changelog_1239_li=Issue 412\: Running the Server tool with just the option "-browser" will now log a warning. 
changelog_1240_li=Issue 411\: CloseWatcher registration was not concurrency-safe. 
changelog_1241_li=MySQL compatibility\: support for CONCAT_WS. Thanks a lot to litailang for the patch\! 
changelog_1242_li=PostgreSQL compatibility\: support for EXTRACT(WEEK FROM dateColumn). Thanks to Prashant Bhat for the patch\! 
changelog_1243_li=Fix for a bug where we would sometimes use the wrong unique constraint to validate foreign key constraints. 
changelog_1244_li=Support BOM at the beginning of files for the RUNSCRIPT command 
changelog_1245_li=Fix in calling SET @X \= IDENTITY() where it would return NULL incorrectly 
changelog_1246_li=Fix ABBA deadlock between adding a constraint and the H2-Log-Writer thread. 
changelog_1247_li=Optimize IN(...) queries where the values are constant and of the same type. 
changelog_1248_li=Restore tool\: the parameter "quiet" was not used and is now removed. 
changelog_1249_li=Fix ConcurrentModificationException when creating tables and executing SHOW TABLES in parallel. Reported by Viktor Voytovych. 
changelog_1250_li=Serialization is now pluggable using the system property "h2.javaObjectSerializer". Thanks to Sergi Vladykin for the patch\! 
cheatSheet_1000_h1=H2 Database Engine Cheat Sheet
cheatSheet_1001_h2=Using H2
cheatSheet_1002_a=H2
cheatSheet_1003_li=\ is <a href\="http\://code.google.com/p/h2database/source">open source</a>, <a href\="license.html">free to use and distribute</a>. 
cheatSheet_1004_a=Download
cheatSheet_1005_li=\: <a href\="http\://repo1.maven.org/maven2/com/h2database/h2/1.4.178/h2-1.4.178.jar" class\="link">jar</a>, <a href\="http\://www.h2database.com/h2-setup-2014-05-02.exe" class\="link">installer (Windows)</a>, <a href\="http\://www.h2database.com/h2-2014-05-02.zip" class\="link">zip</a>. 
cheatSheet_1006_li=To start the <a href\="quickstart.html\#h2_console">H2 Console tool</a>, double click the jar file, or run <code>java -jar h2*.jar</code>, <code>h2.bat</code>, or <code>h2.sh</code>. 
cheatSheet_1007_a=A new database is automatically created
cheatSheet_1008_a=by default
cheatSheet_1009_li=. 
cheatSheet_1010_a=Closing the last connection closes the database
cheatSheet_1011_li=. 
cheatSheet_1012_h2=Documentation
cheatSheet_1013_p=\ Reference\: <a href\="grammar.html" class\="link">SQL grammar</a>, <a href\="functions.html" class\="link">functions</a>, <a href\="datatypes.html" class\="link">data types</a>, <a href\="tutorial.html\#command_line_tools" class\="link">tools</a>, <a href\="../javadoc/index.html" class\="link">API</a> 
cheatSheet_1014_a=Features
cheatSheet_1015_p=\: <a href\="tutorial.html\#fulltext" class\="link">fulltext search</a>, <a href\="features.html\#file_encryption" class\="link">encryption</a>, <a href\="features.html\#read_only" class\="link">read-only</a> <a href\="features.html\#database_in_zip" class\="link">(zip/jar)</a>, <a href\="tutorial.html\#csv" class\="link">CSV</a>, <a href\="features.html\#auto_reconnect" class\="link">auto-reconnect</a>, <a href\="features.html\#triggers" class\="link">triggers</a>, <a href\="features.html\#user_defined_functions" class\="link">user functions</a> 
cheatSheet_1016_a=Database URLs
cheatSheet_1017_a=Embedded
cheatSheet_1018_code=jdbc\:h2\:~/test
cheatSheet_1019_p=\ 'test' in the user home directory
cheatSheet_1020_code=jdbc\:h2\:/data/test
cheatSheet_1021_p=\ 'test' in the directory /data
cheatSheet_1022_code=jdbc\:h2\:test
cheatSheet_1023_p=\ in the current(\!) working directory
cheatSheet_1024_a=In-Memory
cheatSheet_1025_code=jdbc\:h2\:mem\:test
cheatSheet_1026_p=\ multiple connections in one process
cheatSheet_1027_code=jdbc\:h2\:mem\:
cheatSheet_1028_p=\ unnamed private; one connection
cheatSheet_1029_a=Server Mode
cheatSheet_1030_code=jdbc\:h2\:tcp\://localhost/~/test
cheatSheet_1031_p=\ user home dir
cheatSheet_1032_code=jdbc\:h2\:tcp\://localhost//data/test
cheatSheet_1033_p=\ absolute dir
cheatSheet_1034_a=Server start
cheatSheet_1035_p=\:<code>java -cp *.jar org.h2.tools.Server</code> 
cheatSheet_1036_a=Settings
cheatSheet_1037_code=jdbc\:h2\:..;MODE\=MySQL
cheatSheet_1038_a=compatibility (or HSQLDB,...)
cheatSheet_1039_code=jdbc\:h2\:..;TRACE_LEVEL_FILE\=3
cheatSheet_1040_a=log to *.trace.db
cheatSheet_1041_a=Using the JDBC API
cheatSheet_1042_a=Connection Pool
cheatSheet_1043_a=Maven 2
cheatSheet_1044_a=Hibernate
cheatSheet_1045_p=\ hibernate.cfg.xml (or use the HSQLDialect)\: 
cheatSheet_1046_a=TopLink and Glassfish
cheatSheet_1047_p=\ Datasource class\: <code>org.h2.jdbcx.JdbcDataSource</code>
cheatSheet_1048_code=oracle.toplink.essentials.platform.
cheatSheet_1049_code=database.H2Platform
download_1000_h1=Downloads
download_1001_h3=Version 1.4.178 (2014-05-02), Beta
download_1002_a=Windows Installer
download_1003_a=Platform-Independent Zip
download_1004_h3=Version 1.3.176 (2014-04-05), Last Stable
download_1005_a=Windows Installer
download_1006_a=Platform-Independent Zip
download_1007_h3=Download Mirror and Older Versions
download_1008_a=Platform-Independent Zip
download_1009_h3=Jar File
download_1010_a=Maven.org
download_1011_a=Sourceforge.net
download_1012_a=Latest Automated Build (not released)
download_1013_h3=Maven (Binary, Javadoc, and Source)
download_1014_a=Binary
download_1015_a=Javadoc
download_1016_a=Sources
download_1017_h3=Database Upgrade Helper File
download_1018_a=Upgrade database from 1.1 to the current version
download_1019_h3=Subversion Source Repository
download_1020_a=Google Code
download_1021_p=\ For details about changes, see the <a href\="changelog.html">Change Log</a>. 
download_1022_h3=News and Project Information
download_1023_a=Atom Feed
download_1024_a=RSS Feed
download_1025_a=DOAP File
download_1026_p=\ (<a href\="http\://trac.usefulinc.com/doap">what is this</a>) 
faq_1000_h1=Frequently Asked Questions
faq_1001_a=\ I Have a Problem or Feature Request
faq_1002_a=\ Are there Known Bugs? When is the Next Release?
faq_1003_a=\ Is this Database Engine Open Source?
faq_1004_a=\ Is Commercial Support Available?
faq_1005_a=\ How to Create a New Database?
faq_1006_a=\ How to Connect to a Database?
faq_1007_a=\ Where are the Database Files Stored?
faq_1008_a=\ What is the Size Limit (Maximum Size) of a Database?
faq_1009_a=\ Is it Reliable?
faq_1010_a=\ Why is Opening my Database Slow?
faq_1011_a=\ My Query is Slow
faq_1012_a=\ H2 is Very Slow
faq_1013_a=\ Column Names are Incorrect?
faq_1014_a=\ Float is Double?
faq_1015_a=\ Is the GCJ Version Stable? Faster?
faq_1016_a=\ How to Translate this Project?
faq_1017_a=\ How to Contribute to this Project?
faq_1018_h3=I Have a Problem or Feature Request
faq_1019_p=\ Please read the <a href\="build.html\#support">support checklist</a>. 
faq_1020_h3=Are there Known Bugs? When is the Next Release?
faq_1021_p=\ Usually, bugs get fixes as they are found. There is a release every few weeks. Here is the list of known and confirmed issues\: 
faq_1022_li=When opening a database file in a timezone that has different daylight saving rules\: the time part of dates where the daylight saving doesn't match will differ. This is not a problem within regions that use the same rules (such as, within USA, or within Europe), even if the timezone itself is different. As a workaround, export the database to a SQL script using the old timezone, and create a new database in the new timezone. This problem does not occur when using the system property "h2.storeLocalTime" (however such database files are not compatible with older versions of H2). 
faq_1023_li=Apache Harmony\: there seems to be a bug in Harmony that affects H2. See <a href\="https\://issues.apache.org/jira/browse/HARMONY-6505">HARMONY-6505</a>. 
faq_1024_li=Tomcat and Glassfish 3 set most static fields (final or non-final) to <code>null</code> when unloading a web application. This can cause a <code>NullPointerException</code> in H2 versions 1.1.107 and older, and may still not work in newer versions. Please report it if you run into this issue. In Tomcat &gt;\= 6.0 this behavior can be disabled by setting the system property <code>org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES\=false</code>, however Tomcat may then run out of memory. A known workaround is to put the <code>h2*.jar</code> file in a shared <code>lib</code> directory (<code>common/lib</code>). 
faq_1025_li=Some problems have been found with right outer join. Internally, it is converted to left outer join, which does not always produce the same results as other databases when used in combination with other joins. This problem is fixed in H2 version 1.3. 
faq_1026_li=When using Install4j before 4.1.4 on Linux and enabling <code>pack200</code>, the <code>h2*.jar</code> becomes corrupted by the install process, causing application failure. A workaround is to add an empty file <code>h2*.jar.nopack</code> next to the <code>h2*.jar</code> file. This problem is solved in Install4j 4.1.4. 
faq_1027_p=\ For a complete list, see <a href\="http\://code.google.com/p/h2database/issues/list">Open Issues</a>. 
faq_1028_h3=Is this Database Engine Open Source?
faq_1029_p=\ Yes. It is free to use and distribute, and the source code is included. See also under license. 
faq_1030_h3=Is Commercial Support Available?
faq_1031_p=\ Yes, commercial support is available, see <a href\="links.html\#commercial_support">Commercial Support</a>. 
faq_1032_h3=How to Create a New Database?
faq_1033_p=\ By default, a new database is automatically created if it does not yet exist. See <a href\="tutorial.html\#creating_new_databases">Creating New Databases</a>. 
faq_1034_h3=How to Connect to a Database?
faq_1035_p=\ The database driver is <code>org.h2.Driver</code>, and the database URL starts with <code>jdbc\:h2\:</code>. To connect to a database using JDBC, use the following code\: 
faq_1036_h3=Where are the Database Files Stored?
faq_1037_p=\ When using database URLs like <code>jdbc\:h2\:~/test</code>, the database is stored in the user directory. For Windows, this is usually <code>C\:\\Documents and Settings\\&lt;userName&gt;</code> or <code>C\:\\Users\\&lt;userName&gt;</code>. If the base directory is not set (as in <code>jdbc\:h2\:test</code>), the database files are stored in the directory where the application is started (the current working directory). When using the H2 Console application from the start menu, this is <code>&lt;Installation Directory&gt;/bin</code>. The base directory can be set in the database URL. A fixed or relative path can be used. When using the URL <code>jdbc\:h2\:file\:data/sample</code>, the database is stored in the directory <code>data</code> (relative to the current working directory). The directory is created automatically if it does not yet exist. It is also possible to use the fully qualified directory name (and for Windows, drive name). Example\: <code>jdbc\:h2\:file\:C\:/data/test</code> 
faq_1038_h3=What is the Size Limit (Maximum Size) of a Database?
faq_1039_p=\ See <a href\="advanced.html\#limits_limitations">Limits and Limitations</a>. 
faq_1040_h3=Is it Reliable?
faq_1041_p=\ That is not easy to say. It is still a quite new product. A lot of tests have been written, and the code coverage of these tests is higher than 80% for each package. Randomized stress tests are run regularly. But there are probably still bugs that have not yet been found (as with most software). Some features are known to be dangerous, they are only supported for situations where performance is more important than reliability. Those dangerous features are\: 
faq_1042_li=Disabling the transaction log or FileDescriptor.sync() using LOG\=0 or LOG\=1. 
faq_1043_li=Using the transaction isolation level <code>READ_UNCOMMITTED</code> (<code>LOCK_MODE 0</code>) while at the same time using multiple connections. 
faq_1044_li=Disabling database file protection using (setting <code>FILE_LOCK</code> to <code>NO</code> in the database URL). 
faq_1045_li=Disabling referential integrity using <code>SET REFERENTIAL_INTEGRITY FALSE</code>. 
faq_1046_p=\ In addition to that, running out of memory should be avoided. In older versions, OutOfMemory errors while using the database could corrupt a databases. 
faq_1047_p=\ This database is well tested using automated test cases. The tests run every night and run for more than one hour. But not all areas of this database are equally well tested. When using one of the following features for production, please ensure your use case is well tested (if possible with automated test cases). The areas that are not well tested are\: 
faq_1048_li=Platforms other than Windows XP, Linux, Mac OS X, or JVMs other than Sun 1.6 or 1.7 
faq_1049_li=The features <code>AUTO_SERVER</code> and <code>AUTO_RECONNECT</code>. 
faq_1050_li=Cluster mode, 2-phase commit, savepoints. 
faq_1051_li=24/7 operation. 
faq_1052_li=Fulltext search. 
faq_1053_li=Operations on LOBs over 2 GB. 
faq_1054_li=The optimizer may not always select the best plan. 
faq_1055_li=Using the ICU4J collator. 
faq_1056_p=\ Areas considered experimental are\: 
faq_1057_li=The PostgreSQL server 
faq_1058_li=Clustering (there are cases were transaction isolation can be broken due to timing issues, for example one session overtaking another session). 
faq_1059_li=Multi-threading within the engine using <code>SET MULTI_THREADED\=1</code>. 
faq_1060_li=Compatibility modes for other databases (only some features are implemented). 
faq_1061_li=The soft reference cache (<code>CACHE_TYPE\=SOFT_LRU</code>). It might not improve performance, and out of memory issues have been reported. 
faq_1062_p=\ Some users have reported that after a power failure, the database cannot be opened sometimes. In this case, use a backup of the database or the Recover tool. Please report such problems. The plan is that the database automatically recovers in all situations. 
faq_1063_h3=Why is Opening my Database Slow?
faq_1064_p=\ To find out what the problem is, use the H2 Console and click on "Test Connection" instead of "Login". After the "Login Successful" appears, click on it (it's a link). This will list the top stack traces. Then either analyze this yourself, or post those stack traces in the Google Group. 
faq_1065_p=\ Other possible reasons are\: the database is very big (many GB), or contains linked tables that are slow to open. 
faq_1066_h3=My Query is Slow
faq_1067_p=\ Slow <code>SELECT</code> (or <code>DELETE, UPDATE, MERGE</code>) statement can have multiple reasons. Follow this checklist\: 
faq_1068_li=Run <code>ANALYZE</code> (see documentation for details). 
faq_1069_li=Run the query with <code>EXPLAIN</code> and check if indexes are used (see documentation for details). 
faq_1070_li=If required, create additional indexes and try again using <code>ANALYZE</code> and <code>EXPLAIN</code>. 
faq_1071_li=If it doesn't help please report the problem. 
faq_1072_h3=H2 is Very Slow
faq_1073_p=\ By default, H2 closes the database when the last connection is closed. If your application closes the only connection after each operation, the database is opened and closed a lot, which is quite slow. There are multiple ways to solve this problem, see <a href\="performance.html\#database_performance_tuning">Database Performance Tuning</a>. 
faq_1074_h3=Column Names are Incorrect?
faq_1075_p=\ For the query <code>SELECT ID AS X FROM TEST</code> the method <code>ResultSetMetaData.getColumnName()</code> returns <code>ID</code>, I expect it to return <code>X</code>. What's wrong? 
faq_1076_p=\ This is not a bug. According the the JDBC specification, the method <code>ResultSetMetaData.getColumnName()</code> should return the name of the column and not the alias name. If you need the alias name, use <a href\="http\://java.sun.com/javase/6/docs/api/java/sql/ResultSetMetaData.html\#getColumnLabel(int)"><code>ResultSetMetaData.getColumnLabel()</code></a>. Some other database don't work like this yet (they don't follow the JDBC specification). If you need compatibility with those databases, use the <a href\="features.html\#compatibility">Compatibility Mode</a>, or append <a href\="../javadoc/org/h2/engine/DbSettings.html\#ALIAS_COLUMN_NAME"><code>;ALIAS_COLUMN_NAME\=TRUE</code></a> to the database URL. 
faq_1077_p=\ This also applies to DatabaseMetaData calls that return a result set. The columns in the JDBC API are column labels, not column names. 
faq_1078_h3=Float is Double?
faq_1079_p=\ For a table defined as <code>CREATE TABLE TEST(X FLOAT)</code> the method <code>ResultSet.getObject()</code> returns a <code>java.lang.Double</code>, I expect it to return a <code>java.lang.Float</code>. What's wrong? 
faq_1080_p=\ This is not a bug. According the the JDBC specification, the JDBC data type <code>FLOAT</code> is equivalent to <code>DOUBLE</code>, and both are mapped to <code>java.lang.Double</code>. See also <a href\="http\://java.sun.com/j2se/1.5.0/docs/guide/jdbc/getstart/mapping.html\#1055162"> Mapping SQL and Java Types - 8.3.10 FLOAT</a>.
faq_1081_h3=Is the GCJ Version Stable? Faster?
faq_1082_p=\ The GCJ version is not as stable as the Java version. When running the regression test with the GCJ version, sometimes the application just stops at what seems to be a random point without error message. Currently, the GCJ version is also slower than when using the Sun VM. However, the startup of the GCJ version is faster than when using a VM. 
faq_1083_h3=How to Translate this Project?
faq_1084_p=\ For more information, see <a href\="build.html\#translating">Build/Translating</a>. 
faq_1085_h3=How to Contribute to this Project?
faq_1086_p=\ There are various way to help develop an open source project like H2. The first step could be to <a href\="build.html\#translating">translate</a> the error messages and the GUI to your native language. Then, you could <a href\="build.html\#providing_patches">provide patches</a>. Please start with small patches. That could be adding a test case to improve the <a href\="build.html\#automated">code coverage</a> (the target code coverage for this project is 90%, higher is better). You will have to <a href\="build.html">develop, build and run the tests</a>. Once you are familiar with the code, you could implement missing features from the <a href\="roadmap.html">feature request list</a>. I suggest to start with very small features that are easy to implement. Keep in mind to provide test cases as well. 
features_1000_h1=Features
features_1001_a=\ Feature List
features_1002_a=\ Comparison to Other Database Engines
features_1003_a=\ H2 in Use
features_1004_a=\ Connection Modes
features_1005_a=\ Database URL Overview
features_1006_a=\ Connecting to an Embedded (Local) Database
features_1007_a=\ In-Memory Databases
features_1008_a=\ Database Files Encryption
features_1009_a=\ Database File Locking
features_1010_a=\ Opening a Database Only if it Already Exists
features_1011_a=\ Closing a Database
features_1012_a=\ Ignore Unknown Settings
features_1013_a=\ Changing Other Settings when Opening a Connection
features_1014_a=\ Custom File Access Mode
features_1015_a=\ Multiple Connections
features_1016_a=\ Database File Layout
features_1017_a=\ Logging and Recovery
features_1018_a=\ Compatibility
features_1019_a=\ Auto-Reconnect
features_1020_a=\ Automatic Mixed Mode
features_1021_a=\ Page Size
features_1022_a=\ Using the Trace Options
features_1023_a=\ Using Other Logging APIs
features_1024_a=\ Read Only Databases
features_1025_a=\ Read Only Databases in Zip or Jar File
features_1026_a=\ Computed Columns / Function Based Index
features_1027_a=\ Multi-Dimensional Indexes
features_1028_a=\ User-Defined Functions and Stored Procedures
features_1029_a=\ Pluggable or User-Defined Tables
features_1030_a=\ Triggers
features_1031_a=\ Compacting a Database
features_1032_a=\ Cache Settings
features_1033_h2=Feature List
features_1034_h3=Main Features
features_1035_li=Very fast database engine 
features_1036_li=Open source 
features_1037_li=Written in Java 
features_1038_li=Supports standard SQL, JDBC API 
features_1039_li=Embedded and Server mode, Clustering support 
features_1040_li=Strong security features 
features_1041_li=The PostgreSQL ODBC driver can be used 
features_1042_li=Multi version concurrency 
features_1043_h3=Additional Features
features_1044_li=Disk based or in-memory databases and tables, read-only database support, temporary tables 
features_1045_li=Transaction support (read committed and serializable transaction isolation), 2-phase-commit 
features_1046_li=Multiple connections, table level locking 
features_1047_li=Cost based optimizer, using a genetic algorithm for complex queries, zero-administration 
features_1048_li=Scrollable and updatable result set support, large result set, external result sorting, functions can return a result set 
features_1049_li=Encrypted database (AES), SHA-256 password encryption, encryption functions, SSL 
features_1050_h3=SQL Support
features_1051_li=Support for multiple schemas, information schema 
features_1052_li=Referential integrity / foreign key constraints with cascade, check constraints 
features_1053_li=Inner and outer joins, subqueries, read only views and inline views 
features_1054_li=Triggers and Java functions / stored procedures 
features_1055_li=Many built-in functions, including XML and lossless data compression 
features_1056_li=Wide range of data types including large objects (BLOB/CLOB) and arrays 
features_1057_li=Sequence and autoincrement columns, computed columns (can be used for function based indexes) 
features_1058_code=ORDER BY, GROUP BY, HAVING, UNION, LIMIT, TOP
features_1059_li=Collation support, including support for the ICU4J library 
features_1060_li=Support for users and roles 
features_1061_li=Compatibility modes for IBM DB2, Apache Derby, HSQLDB, MS SQL Server, MySQL, Oracle, and PostgreSQL. 
features_1062_h3=Security Features
features_1063_li=Includes a solution for the SQL injection problem 
features_1064_li=User password authentication uses SHA-256 and salt 
features_1065_li=For server mode connections, user passwords are never transmitted in plain text over the network (even when using insecure connections; this only applies to the TCP server and not to the H2 Console however; it also doesn't apply if you set the password in the database URL) 
features_1066_li=All database files (including script files that can be used to backup data) can be encrypted using the AES-128 encryption algorithm 
features_1067_li=The remote JDBC driver supports TCP/IP connections over SSL/TLS 
features_1068_li=The built-in web server supports connections over SSL/TLS 
features_1069_li=Passwords can be sent to the database using char arrays instead of Strings 
features_1070_h3=Other Features and Tools
features_1071_li=Small footprint (smaller than 1.5 MB), low memory requirements 
features_1072_li=Multiple index types (b-tree, tree, hash) 
features_1073_li=Support for multi-dimensional indexes 
features_1074_li=CSV (comma separated values) file support 
features_1075_li=Support for linked tables, and a built-in virtual 'range' table 
features_1076_li=Supports the <code>EXPLAIN PLAN</code> statement; sophisticated trace options 
features_1077_li=Database closing can be delayed or disabled to improve the performance 
features_1078_li=Web-based Console application (translated to many languages) with autocomplete 
features_1079_li=The database can generate SQL script files 
features_1080_li=Contains a recovery tool that can dump the contents of the database 
features_1081_li=Support for variables (for example to calculate running totals) 
features_1082_li=Automatic re-compilation of prepared statements 
features_1083_li=Uses a small number of database files 
features_1084_li=Uses a checksum for each record and log entry for data integrity 
features_1085_li=Well tested (high code coverage, randomized stress tests) 
features_1086_h2=Comparison to Other Database Engines
features_1087_p=\ This comparison is based on H2 1.3, <a href\="http\://db.apache.org/derby">Apache Derby version 10.8</a>, <a href\="http\://hsqldb.org">HSQLDB 2.2</a>, <a href\="http\://mysql.com">MySQL 5.5</a>, <a href\="http\://www.postgresql.org">PostgreSQL 9.0</a>. 
features_1088_th=Feature
features_1089_th=H2
features_1090_th=Derby
features_1091_th=HSQLDB
features_1092_th=MySQL
features_1093_th=PostgreSQL
features_1094_td=Pure Java
features_1095_td=Yes
features_1096_td=Yes
features_1097_td=Yes
features_1098_td=No
features_1099_td=No
features_1100_td=Embedded Mode (Java)
features_1101_td=Yes
features_1102_td=Yes
features_1103_td=Yes
features_1104_td=No
features_1105_td=No
features_1106_td=In-Memory Mode
features_1107_td=Yes
features_1108_td=Yes
features_1109_td=Yes
features_1110_td=No
features_1111_td=No
features_1112_td=Explain Plan
features_1113_td=Yes
features_1114_td=Yes *12
features_1115_td=Yes
features_1116_td=Yes
features_1117_td=Yes
features_1118_td=Built-in Clustering / Replication
features_1119_td=Yes
features_1120_td=Yes
features_1121_td=No
features_1122_td=Yes
features_1123_td=Yes
features_1124_td=Encrypted Database
features_1125_td=Yes
features_1126_td=Yes *10
features_1127_td=Yes *10
features_1128_td=No
features_1129_td=No
features_1130_td=Linked Tables
features_1131_td=Yes
features_1132_td=No
features_1133_td=Partially *1
features_1134_td=Partially *2
features_1135_td=No
features_1136_td=ODBC Driver
features_1137_td=Yes
features_1138_td=No
features_1139_td=No
features_1140_td=Yes
features_1141_td=Yes
features_1142_td=Fulltext Search
features_1143_td=Yes
features_1144_td=No
features_1145_td=No
features_1146_td=Yes
features_1147_td=Yes
features_1148_td=Domains (User-Defined Types)
features_1149_td=Yes
features_1150_td=No
features_1151_td=Yes
features_1152_td=Yes
features_1153_td=Yes
features_1154_td=Files per Database
features_1155_td=Few
features_1156_td=Many
features_1157_td=Few
features_1158_td=Many
features_1159_td=Many
features_1160_td=Row Level Locking
features_1161_td=Yes *9
features_1162_td=Yes
features_1163_td=Yes *9
features_1164_td=Yes
features_1165_td=Yes
features_1166_td=Multi Version Concurrency
features_1167_td=Yes
features_1168_td=No
features_1169_td=Yes
features_1170_td=Yes
features_1171_td=Yes
features_1172_td=Multi-Threaded Statement Processing
features_1173_td=No *11
features_1174_td=Yes
features_1175_td=Yes
features_1176_td=Yes
features_1177_td=Yes
features_1178_td=Role Based Security
features_1179_td=Yes
features_1180_td=Yes *3
features_1181_td=Yes
features_1182_td=Yes
features_1183_td=Yes
features_1184_td=Updatable Result Sets
features_1185_td=Yes
features_1186_td=Yes *7
features_1187_td=Yes
features_1188_td=Yes
features_1189_td=Yes
features_1190_td=Sequences
features_1191_td=Yes
features_1192_td=Yes
features_1193_td=Yes
features_1194_td=No
features_1195_td=Yes
features_1196_td=Limit and Offset
features_1197_td=Yes
features_1198_td=Yes *13
features_1199_td=Yes
features_1200_td=Yes
features_1201_td=Yes
features_1202_td=Window Functions
features_1203_td=No *15
features_1204_td=No *15
features_1205_td=No
features_1206_td=No
features_1207_td=Yes
features_1208_td=Temporary Tables
features_1209_td=Yes
features_1210_td=Yes *4
features_1211_td=Yes
features_1212_td=Yes
features_1213_td=Yes
features_1214_td=Information Schema
features_1215_td=Yes
features_1216_td=No *8
features_1217_td=Yes
features_1218_td=Yes
features_1219_td=Yes
features_1220_td=Computed Columns
features_1221_td=Yes
features_1222_td=Yes
features_1223_td=Yes
features_1224_td=No
features_1225_td=Yes *6
features_1226_td=Case Insensitive Columns
features_1227_td=Yes
features_1228_td=Yes *14
features_1229_td=Yes
features_1230_td=Yes
features_1231_td=Yes *6
features_1232_td=Custom Aggregate Functions
features_1233_td=Yes
features_1234_td=No
features_1235_td=Yes
features_1236_td=Yes
features_1237_td=Yes
features_1238_td=CLOB/BLOB Compression
features_1239_td=Yes
features_1240_td=No
features_1241_td=No
features_1242_td=No
features_1243_td=Yes
features_1244_td=Footprint (jar/dll size)
features_1245_td=~1.5 MB *5
features_1246_td=~3 MB
features_1247_td=~1.5 MB
features_1248_td=~4 MB
features_1249_td=~6 MB
features_1250_p=\ *1 HSQLDB supports text tables.
features_1251_p=\ *2 MySQL supports linked MySQL tables under the name 'federated tables'.
features_1252_p=\ *3 Derby support for roles based security and password checking as an option.
features_1253_p=\ *4 Derby only supports global temporary tables.
features_1254_p=\ *5 The default H2 jar file contains debug information, jar files for other databases do not.
features_1255_p=\ *6 PostgreSQL supports functional indexes.
features_1256_p=\ *7 Derby only supports updatable result sets if the query is not sorted.
features_1257_p=\ *8 Derby doesn't support standard compliant information schema tables.
features_1258_p=\ *9 When using MVCC (multi version concurrency).
features_1259_p=\ *10 Derby and HSQLDB <a href\="http\://en.wikipedia.org/wiki/Block_cipher_modes_of_operation\#Electronic_codebook_.28ECB.29">don't hide data patterns well</a>.
features_1260_p=\ *11 The MULTI_THREADED option is not enabled by default, and not yet supported when using MVCC.
features_1261_p=\ *12 Derby doesn't support the <code>EXPLAIN</code> statement, but it supports runtime statistics and retrieving statement execution plans.
features_1262_p=\ *13 Derby doesn't support the syntax <code>LIMIT .. [OFFSET ..]</code>, however it supports <code>FETCH FIRST .. ROW[S] ONLY</code>.
features_1263_p=\ *14 Using collations. *15 Derby and H2 support <code>ROW_NUMBER() OVER()</code>. 
features_1264_h3=DaffodilDb and One$Db
features_1265_p=\ It looks like the development of this database has stopped. The last release was February 2006. 
features_1266_h3=McKoi
features_1267_p=\ It looks like the development of this database has stopped. The last release was August 2004. 
features_1268_h2=H2 in Use
features_1269_p=\ For a list of applications that work with or use H2, see\: <a href\="links.html">Links</a>. 
features_1270_h2=Connection Modes
features_1271_p=\ The following connection modes are supported\: 
features_1272_li=Embedded mode (local connections using JDBC) 
features_1273_li=Server mode (remote connections using JDBC or ODBC over TCP/IP) 
features_1274_li=Mixed mode (local and remote connections at the same time) 
features_1275_h3=Embedded Mode
features_1276_p=\ In embedded mode, an application opens a database from within the same JVM using JDBC. This is the fastest and easiest connection mode. The disadvantage is that a database may only be open in one virtual machine (and class loader) at any time. As in all modes, both persistent and in-memory databases are supported. There is no limit on the number of database open concurrently, or on the number of open connections. 
features_1277_h3=Server Mode
features_1278_p=\ When using the server mode (sometimes called remote mode or client/server mode), an application opens a database remotely using the JDBC or ODBC API. A server needs to be started within the same or another virtual machine, or on another computer. Many applications can connect to the same database at the same time, by connecting to this server. Internally, the server process opens the database(s) in embedded mode. 
features_1279_p=\ The server mode is slower than the embedded mode, because all data is transferred over TCP/IP. As in all modes, both persistent and in-memory databases are supported. There is no limit on the number of database open concurrently per server, or on the number of open connections. 
features_1280_h3=Mixed Mode
features_1281_p=\ The mixed mode is a combination of the embedded and the server mode. The first application that connects to a database does that in embedded mode, but also starts a server so that other applications (running in different processes or virtual machines) can concurrently access the same data. The local connections are as fast as if the database is used in just the embedded mode, while the remote connections are a bit slower. 
features_1282_p=\ The server can be started and stopped from within the application (using the server API), or automatically (automatic mixed mode). When using the <a href\="\#auto_mixed_mode">automatic mixed mode</a>, all clients that want to connect to the database (no matter if it's an local or remote connection) can do so using the exact same database URL. 
features_1283_h2=Database URL Overview
features_1284_p=\ This database supports multiple connection modes and connection settings. This is achieved using different database URLs. Settings in the URLs are not case sensitive. 
features_1285_th=Topic
features_1286_th=URL Format and Examples
features_1287_a=Embedded (local) connection
features_1288_td=\ jdbc\:h2\:[file\:][&lt;path&gt;]&lt;databaseName&gt;
features_1289_td=\ jdbc\:h2\:~/test
features_1290_td=\ jdbc\:h2\:file\:/data/sample
features_1291_td=\ jdbc\:h2\:file\:C\:/data/sample (Windows only)
features_1292_a=In-memory (private)
features_1293_td=jdbc\:h2\:mem\:
features_1294_a=In-memory (named)
features_1295_td=\ jdbc\:h2\:mem\:&lt;databaseName&gt;
features_1296_td=\ jdbc\:h2\:mem\:test_mem 
features_1297_a=Server mode (remote connections)
features_1298_a=\ using TCP/IP
features_1299_td=\ jdbc\:h2\:tcp\://&lt;server&gt;[\:&lt;port&gt;]/[&lt;path&gt;]&lt;databaseName&gt;
features_1300_td=\ jdbc\:h2\:tcp\://localhost/~/test
features_1301_td=\ jdbc\:h2\:tcp\://dbserv\:8084/~/sample
features_1302_td=\ jdbc\:h2\:tcp\://localhost/mem\:test
features_1303_a=Server mode (remote connections)
features_1304_a=\ using SSL/TLS
features_1305_td=\ jdbc\:h2\:ssl\://&lt;server&gt;[\:&lt;port&gt;]/&lt;databaseName&gt;
features_1306_td=\ jdbc\:h2\:ssl\://localhost\:8085/~/sample; 
features_1307_a=Using encrypted files
features_1308_td=\ jdbc\:h2\:&lt;url&gt;;CIPHER\=AES
features_1309_td=\ jdbc\:h2\:ssl\://localhost/~/test;CIPHER\=AES
features_1310_td=\ jdbc\:h2\:file\:~/secure;CIPHER\=AES
features_1311_a=File locking methods
features_1312_td=\ jdbc\:h2\:&lt;url&gt;;FILE_LOCK\={FILE|SOCKET|NO}
features_1313_td=\ jdbc\:h2\:file\:~/private;CIPHER\=AES;FILE_LOCK\=SOCKET
features_1314_a=Only open if it already exists
features_1315_td=\ jdbc\:h2\:&lt;url&gt;;IFEXISTS\=TRUE
features_1316_td=\ jdbc\:h2\:file\:~/sample;IFEXISTS\=TRUE
features_1317_a=Don't close the database when the VM exits
features_1318_td=\ jdbc\:h2\:&lt;url&gt;;DB_CLOSE_ON_EXIT\=FALSE 
features_1319_a=Execute SQL on connection
features_1320_td=\ jdbc\:h2\:&lt;url&gt;;INIT\=RUNSCRIPT FROM '~/create.sql'
features_1321_td=\ jdbc\:h2\:file\:~/sample;INIT\=RUNSCRIPT FROM '~/create.sql'\\;RUNSCRIPT FROM '~/populate.sql'
features_1322_a=User name and/or password
features_1323_td=\ jdbc\:h2\:&lt;url&gt;[;USER\=&lt;username&gt;][;PASSWORD\=&lt;value&gt;]
features_1324_td=\ jdbc\:h2\:file\:~/sample;USER\=sa;PASSWORD\=123
features_1325_a=Debug trace settings
features_1326_td=\ jdbc\:h2\:&lt;url&gt;;TRACE_LEVEL_FILE\=&lt;level 0..3&gt;
features_1327_td=\ jdbc\:h2\:file\:~/sample;TRACE_LEVEL_FILE\=3
features_1328_a=Ignore unknown settings
features_1329_td=\ jdbc\:h2\:&lt;url&gt;;IGNORE_UNKNOWN_SETTINGS\=TRUE
features_1330_a=Custom file access mode
features_1331_td=\ jdbc\:h2\:&lt;url&gt;;ACCESS_MODE_DATA\=rws
features_1332_a=Database in a zip file
features_1333_td=\ jdbc\:h2\:zip\:&lt;zipFileName&gt;\!/&lt;databaseName&gt;
features_1334_td=\ jdbc\:h2\:zip\:~/db.zip\!/test 
features_1335_a=Compatibility mode
features_1336_td=\ jdbc\:h2\:&lt;url&gt;;MODE\=&lt;databaseType&gt;
features_1337_td=\ jdbc\:h2\:~/test;MODE\=MYSQL 
features_1338_a=Auto-reconnect
features_1339_td=\ jdbc\:h2\:&lt;url&gt;;AUTO_RECONNECT\=TRUE
features_1340_td=\ jdbc\:h2\:tcp\://localhost/~/test;AUTO_RECONNECT\=TRUE 
features_1341_a=Automatic mixed mode
features_1342_td=\ jdbc\:h2\:&lt;url&gt;;AUTO_SERVER\=TRUE
features_1343_td=\ jdbc\:h2\:~/test;AUTO_SERVER\=TRUE 
features_1344_a=Page size
features_1345_td=\ jdbc\:h2\:&lt;url&gt;;PAGE_SIZE\=512
features_1346_a=Changing other settings
features_1347_td=\ jdbc\:h2\:&lt;url&gt;;&lt;setting&gt;\=&lt;value&gt;[;&lt;setting&gt;\=&lt;value&gt;...]
features_1348_td=\ jdbc\:h2\:file\:~/sample;TRACE_LEVEL_SYSTEM_OUT\=3
features_1349_h2=Connecting to an Embedded (Local) Database
features_1350_p=\ The database URL for connecting to a local database is <code>jdbc\:h2\:[file\:][&lt;path&gt;]&lt;databaseName&gt;</code>. The prefix <code>file\:</code> is optional. If no or only a relative path is used, then the current working directory is used as a starting point. The case sensitivity of the path and database name depend on the operating system, however it is recommended to use lowercase letters only. The database name must be at least three characters long (a limitation of <code>File.createTempFile</code>). The database name must not contain a semicolon. To point to the user home directory, use <code>~/</code>, as in\: <code>jdbc\:h2\:~/test</code>. 
features_1351_h2=In-Memory Databases
features_1352_p=\ For certain use cases (for example\: rapid prototyping, testing, high performance operations, read-only databases), it may not be required to persist data, or persist changes to the data. This database supports the in-memory mode, where the data is not persisted. 
features_1353_p=\ In some cases, only one connection to a in-memory database is required. This means the database to be opened is private. In this case, the database URL is <code>jdbc\:h2\:mem\:</code> Opening two connections within the same virtual machine means opening two different (private) databases. 
features_1354_p=\ Sometimes multiple connections to the same in-memory database are required. In this case, the database URL must include a name. Example\: <code>jdbc\:h2\:mem\:db1</code>. Accessing the same database using this URL only works within the same virtual machine and class loader environment. 
features_1355_p=\ To access an in-memory database from another process or from another computer, you need to start a TCP server in the same process as the in-memory database was created. The other processes then need to access the database over TCP/IP or SSL/TLS, using a database URL such as\: <code>jdbc\:h2\:tcp\://localhost/mem\:db1</code>. 
features_1356_p=\ By default, closing the last connection to a database closes the database. For an in-memory database, this means the content is lost. To keep the database open, add <code>;DB_CLOSE_DELAY\=-1</code> to the database URL. To keep the content of an in-memory database as long as the virtual machine is alive, use <code>jdbc\:h2\:mem\:test;DB_CLOSE_DELAY\=-1</code>. 
features_1357_h2=Database Files Encryption
features_1358_p=\ The database files can be encrypted. Two encryption algorithm AES is supported. To use file encryption, you need to specify the encryption algorithm (the 'cipher') and the file password (in addition to the user password) when connecting to the database. 
features_1359_h3=Creating a New Database with File Encryption
features_1360_p=\ By default, a new database is automatically created if it does not exist yet. To create an encrypted database, connect to it as it would already exist. 
features_1361_h3=Connecting to an Encrypted Database
features_1362_p=\ The encryption algorithm is set in the database URL, and the file password is specified in the password field, before the user password. A single space separates the file password and the user password; the file password itself may not contain spaces. File passwords and user passwords are case sensitive. Here is an example to connect to a password-encrypted database\: 
features_1363_h3=Encrypting or Decrypting a Database
features_1364_p=\ To encrypt an existing database, use the <code>ChangeFileEncryption</code> tool. This tool can also decrypt an encrypted database, or change the file encryption key. The tool is available from within the H2 Console in the tools section, or you can run it from the command line. The following command line will encrypt the database <code>test</code> in the user home directory with the file password <code>filepwd</code> and the encryption algorithm AES\: 
features_1365_h2=Database File Locking
features_1366_p=\ Whenever a database is opened, a lock file is created to signal other processes that the database is in use. If database is closed, or if the process that opened the database terminates, this lock file is deleted. 
features_1367_p=\ The following file locking methods are implemented\: 
features_1368_li=The default method is <code>FILE</code> and uses a watchdog thread to protect the database file. The watchdog reads the lock file each second. 
features_1369_li=The second method is <code>SOCKET</code> and opens a server socket. The socket method does not require reading the lock file every second. The socket method should only be used if the database files are only accessed by one (and always the same) computer. 
features_1370_li=The third method is <code>FS</code>. This will use native file locking using <code>FileChannel.lock</code>. 
features_1371_li=It is also possible to open the database without file locking; in this case it is up to the application to protect the database files. Failing to do so will result in a corrupted database. Using the method <code>NO</code> forces the database to not create a lock file at all. Please note that this is unsafe as another process is able to open the same database, possibly leading to data corruption.
features_1372_p=\ To open the database with a different file locking method, use the parameter <code>FILE_LOCK</code>. The following code opens the database with the 'socket' locking method\: 
features_1373_p=\ For more information about the algorithms, see <a href\="advanced.html\#file_locking_protocols">Advanced / File Locking Protocols</a>. 
features_1374_h2=Opening a Database Only if it Already Exists
features_1375_p=\ By default, when an application calls <code>DriverManager.getConnection(url, ...)</code> and the database specified in the URL does not yet exist, a new (empty) database is created. In some situations, it is better to restrict creating new databases, and only allow to open existing databases. To do this, add <code>;IFEXISTS\=TRUE</code> to the database URL. In this case, if the database does not already exist, an exception is thrown when trying to connect. The connection only succeeds when the database already exists. The complete URL may look like this\: 
features_1376_h2=Closing a Database
features_1377_h3=Delayed Database Closing
features_1378_p=\ Usually, a database is closed when the last connection to it is closed. In some situations this slows down the application, for example when it is not possible to keep at least one connection open. The automatic closing of a database can be delayed or disabled with the SQL statement <code>SET DB_CLOSE_DELAY &lt;seconds&gt;</code>. The parameter &lt;seconds&gt; specifies the number of seconds to keep a database open after the last connection to it was closed. The following statement will keep a database open for 10 seconds after the last connection was closed\: 
features_1379_p=\ The value -1 means the database is not closed automatically. The value 0 is the default and means the database is closed when the last connection is closed. This setting is persistent and can be set by an administrator only. It is possible to set the value in the database URL\: <code>jdbc\:h2\:~/test;DB_CLOSE_DELAY\=10</code>. 
features_1380_h3=Don't Close a Database when the VM Exits
features_1381_p=\ By default, a database is closed when the last connection is closed. However, if it is never closed, the database is closed when the virtual machine exits normally, using a shutdown hook. In some situations, the database should not be closed in this case, for example because the database is still used at virtual machine shutdown (to store the shutdown process in the database for example). For those cases, the automatic closing of the database can be disabled in the database URL. The first connection (the one that is opening the database) needs to set the option in the database URL (it is not possible to change the setting afterwards). The database URL to disable database closing on exit is\: 
features_1382_h2=Execute SQL on Connection
features_1383_p=\ Sometimes, particularly for in-memory databases, it is useful to be able to execute DDL or DML commands automatically when a client connects to a database. This functionality is enabled via the INIT property. Note that multiple commands may be passed to INIT, but the semicolon delimiter must be escaped, as in the example below. 
features_1384_p=\ Please note the double backslash is only required in a Java or properties file. In a GUI, or in an XML file, only one backslash is required\: 
features_1385_p=\ Backslashes within the init script (for example within a runscript statement, to specify the folder names in Windows) need to be escaped as well (using a second backslash). It might be simpler to avoid backslashes in folder names for this reason; use forward slashes instead. 
features_1386_h2=Ignore Unknown Settings
features_1387_p=\ Some applications (for example OpenOffice.org Base) pass some additional parameters when connecting to the database. Why those parameters are passed is unknown. The parameters <code>PREFERDOSLIKELINEENDS</code> and <code>IGNOREDRIVERPRIVILEGES</code> are such examples; they are simply ignored to improve the compatibility with OpenOffice.org. If an application passes other parameters when connecting to the database, usually the database throws an exception saying the parameter is not supported. It is possible to ignored such parameters by adding <code>;IGNORE_UNKNOWN_SETTINGS\=TRUE</code> to the database URL. 
features_1388_h2=Changing Other Settings when Opening a Connection
features_1389_p=\ In addition to the settings already described, other database settings can be passed in the database URL. Adding <code>;setting\=value</code> at the end of a database URL is the same as executing the statement <code>SET setting value</code> just after connecting. For a list of supported settings, see <a href\="grammar.html">SQL Grammar</a> or the <a href\="../javadoc/org/h2/engine/DbSettings.html">DbSettings</a> javadoc. 
features_1390_h2=Custom File Access Mode
features_1391_p=\ Usually, the database opens the database file with the access mode <code>rw</code>, meaning read-write (except for read only databases, where the mode <code>r</code> is used). To open a database in read-only mode if the database file is not read-only, use <code>ACCESS_MODE_DATA\=r</code>. Also supported are <code>rws</code> and <code>rwd</code>. This setting must be specified in the database URL\: 
features_1392_p=\ For more information see <a href\="advanced.html\#durability_problems">Durability Problems</a>. On many operating systems the access mode <code>rws</code> does not guarantee that the data is written to the disk. 
features_1393_h2=Multiple Connections
features_1394_h3=Opening Multiple Databases at the Same Time
features_1395_p=\ An application can open multiple databases at the same time, including multiple connections to the same database. The number of open database is only limited by the memory available. 
features_1396_h3=Multiple Connections to the Same Database\: Client/Server
features_1397_p=\ If you want to access the same database at the same time from different processes or computers, you need to use the client / server mode. In this case, one process acts as the server, and the other processes (that could reside on other computers as well) connect to the server via TCP/IP (or SSL/TLS over TCP/IP for improved security). 
features_1398_h3=Multithreading Support
features_1399_p=\ This database is multithreading-safe. That means, if an application is multi-threaded, it does not need to worry about synchronizing access to the database. Internally, most requests to the same database are synchronized. That means an application can use multiple threads that access the same database at the same time, however if one thread executes a long running query, the other threads need to wait. 
features_1400_p=\ An application should normally use one connection per thread. This database synchronizes access to the same connection, but other databases may not do this. 
features_1401_h3=Locking, Lock-Timeout, Deadlocks
features_1402_p=\ Unless <a href\="advanced.html\#mvcc">multi-version concurrency</a> is used, the database uses table level locks to give each connection a consistent state of the data. There are two kinds of locks\: read locks (shared locks) and write locks (exclusive locks). All locks are released when the transaction commits or rolls back. When using the default transaction isolation level 'read committed', read locks are already released after each statement. 
features_1403_p=\ If a connection wants to reads from a table, and there is no write lock on the table, then a read lock is added to the table. If there is a write lock, then this connection waits for the other connection to release the lock. If a connection cannot get a lock for a specified time, then a lock timeout exception is thrown. 
features_1404_p=\ Usually, <code>SELECT</code> statements will generate read locks. This includes subqueries. Statements that modify data use write locks. It is also possible to lock a table exclusively without modifying data, using the statement <code>SELECT ... FOR UPDATE</code>. The statements <code>COMMIT</code> and <code>ROLLBACK</code> releases all open locks. The commands <code>SAVEPOINT</code> and <code>ROLLBACK TO SAVEPOINT</code> don't affect locks. The locks are also released when the autocommit mode changes, and for connections with autocommit set to true (this is the default), locks are released after each statement. The following statements generate locks\: 
features_1405_th=Type of Lock
features_1406_th=SQL Statement
features_1407_td=Read
features_1408_td=SELECT * FROM TEST;
features_1409_td=\ CALL SELECT MAX(ID) FROM TEST;
features_1410_td=\ SCRIPT;
features_1411_td=Write
features_1412_td=SELECT * FROM TEST WHERE 1\=0 FOR UPDATE;
features_1413_td=Write
features_1414_td=INSERT INTO TEST VALUES(1, 'Hello');
features_1415_td=\ INSERT INTO TEST SELECT * FROM TEST;
features_1416_td=\ UPDATE TEST SET NAME\='Hi';
features_1417_td=\ DELETE FROM TEST;
features_1418_td=Write
features_1419_td=ALTER TABLE TEST ...;
features_1420_td=\ CREATE INDEX ... ON TEST ...;
features_1421_td=\ DROP INDEX ...;
features_1422_p=\ The number of seconds until a lock timeout exception is thrown can be set separately for each connection using the SQL command <code>SET LOCK_TIMEOUT &lt;milliseconds&gt;</code>. The initial lock timeout (that is the timeout used for new connections) can be set using the SQL command <code>SET DEFAULT_LOCK_TIMEOUT &lt;milliseconds&gt;</code>. The default lock timeout is persistent. 
features_1423_h3=Avoiding Deadlocks
features_1424_p=\ To avoid deadlocks, ensure that all transactions lock the tables in the same order (for example in alphabetical order), and avoid upgrading read locks to write locks. Both can be achieved using explicitly locking tables using <code>SELECT ... FOR UPDATE</code>. 
features_1425_h2=Database File Layout
features_1426_p=\ The following files are created for persistent databases\: 
features_1427_th=File Name
features_1428_th=Description
features_1429_th=Number of Files
features_1430_td=\ test.h2.db 
features_1431_td=\ Database file.
features_1432_td=\ Contains the transaction log, indexes, and data for all tables.
features_1433_td=\ Format\: <code>&lt;database&gt;.h2.db</code> 
features_1434_td=\ 1 per database 
features_1435_td=\ test.lock.db 
features_1436_td=\ Database lock file.
features_1437_td=\ Automatically (re-)created while the database is in use.
features_1438_td=\ Format\: <code>&lt;database&gt;.lock.db</code> 
features_1439_td=\ 1 per database (only if in use) 
features_1440_td=\ test.trace.db 
features_1441_td=\ Trace file (if the trace option is enabled).
features_1442_td=\ Contains trace information.
features_1443_td=\ Format\: <code>&lt;database&gt;.trace.db</code>
features_1444_td=\ Renamed to <code>&lt;database&gt;.trace.db.old</code> is too big. 
features_1445_td=\ 0 or 1 per database 
features_1446_td=\ test.lobs.db/* 
features_1447_td=\ Directory containing one file for each
features_1448_td=\ BLOB or CLOB value larger than a certain size.
features_1449_td=\ Format\: <code>&lt;id&gt;.t&lt;tableId&gt;.lob.db</code> 
features_1450_td=\ 1 per large object 
features_1451_td=\ test.123.temp.db 
features_1452_td=\ Temporary file.
features_1453_td=\ Contains a temporary blob or a large result set.
features_1454_td=\ Format\: <code>&lt;database&gt;.&lt;id&gt;.temp.db</code> 
features_1455_td=\ 1 per object 
features_1456_h3=Moving and Renaming Database Files
features_1457_p=\ Database name and location are not stored inside the database files. 
features_1458_p=\ While a database is closed, the files can be moved to another directory, and they can be renamed as well (as long as all files of the same database start with the same name and the respective extensions are unchanged). 
features_1459_p=\ As there is no platform specific data in the files, they can be moved to other operating systems without problems. 
features_1460_h3=Backup
features_1461_p=\ When the database is closed, it is possible to backup the database files. 
features_1462_p=\ To backup data while the database is running, the SQL commands <code>SCRIPT</code> and <code>BACKUP</code> can be used. 
features_1463_h2=Logging and Recovery
features_1464_p=\ Whenever data is modified in the database and those changes are committed, the changes are written to the transaction log (except for in-memory objects). The changes to the main data area itself are usually written later on, to optimize disk access. If there is a power failure, the main data area is not up-to-date, but because the changes are in the transaction log, the next time the database is opened, the changes are re-applied automatically. 
features_1465_h2=Compatibility
features_1466_p=\ All database engines behave a little bit different. Where possible, H2 supports the ANSI SQL standard, and tries to be compatible to other databases. There are still a few differences however\: 
features_1467_p=\ In MySQL text columns are case insensitive by default, while in H2 they are case sensitive. However H2 supports case insensitive columns as well. To create the tables with case insensitive texts, append <code>IGNORECASE\=TRUE</code> to the database URL (example\: <code>jdbc\:h2\:~/test;IGNORECASE\=TRUE</code>). 
features_1468_h3=Compatibility Modes
features_1469_p=\ For certain features, this database can emulate the behavior of specific databases. However, only a small subset of the differences between databases are implemented in this way. Here is the list of currently supported modes and the differences to the regular mode\: 
features_1470_h3=DB2 Compatibility Mode
features_1471_p=\ To use the IBM DB2 mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=DB2</code> or the SQL statement <code>SET MODE DB2</code>. 
features_1472_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1473_li=Support for the syntax <code>[OFFSET .. ROW] [FETCH ... ONLY]</code> as an alternative for <code>LIMIT .. OFFSET</code>. 
features_1474_li=Concatenating <code>NULL</code> with another value results in the other value. 
features_1475_li=Support the pseudo-table SYSIBM.SYSDUMMY1. 
features_1476_h3=Derby Compatibility Mode
features_1477_p=\ To use the Apache Derby mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=Derby</code> or the SQL statement <code>SET MODE Derby</code>. 
features_1478_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1479_li=For unique indexes, <code>NULL</code> is distinct. That means only one row with <code>NULL</code> in one of the columns is allowed. 
features_1480_li=Concatenating <code>NULL</code> with another value results in the other value. 
features_1481_li=Support the pseudo-table SYSIBM.SYSDUMMY1. 
features_1482_h3=HSQLDB Compatibility Mode
features_1483_p=\ To use the HSQLDB mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=HSQLDB</code> or the SQL statement <code>SET MODE HSQLDB</code>. 
features_1484_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1485_li=When converting the scale of decimal data, the number is only converted if the new scale is smaller than the current scale. Usually, the scale is converted and 0s are added if required. 
features_1486_li=For unique indexes, <code>NULL</code> is distinct. That means only one row with <code>NULL</code> in one of the columns is allowed. 
features_1487_li=Text can be concatenated using '+'. 
features_1488_h3=MS SQL Server Compatibility Mode
features_1489_p=\ To use the MS SQL Server mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=MSSQLServer</code> or the SQL statement <code>SET MODE MSSQLServer</code>. 
features_1490_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1491_li=Identifiers may be quoted using square brackets as in <code>[Test]</code>. 
features_1492_li=For unique indexes, <code>NULL</code> is distinct. That means only one row with <code>NULL</code> in one of the columns is allowed. 
features_1493_li=Concatenating <code>NULL</code> with another value results in the other value. 
features_1494_li=Text can be concatenated using '+'. 
features_1495_h3=MySQL Compatibility Mode
features_1496_p=\ To use the MySQL mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=MySQL</code> or the SQL statement <code>SET MODE MySQL</code>. 
features_1497_li=When inserting data, if a column is defined to be <code>NOT NULL</code> and <code>NULL</code> is inserted, then a 0 (or empty string, or the current timestamp for timestamp columns) value is used. Usually, this operation is not allowed and an exception is thrown. 
features_1498_li=Creating indexes in the <code>CREATE TABLE</code> statement is allowed using <code>INDEX(..)</code> or <code>KEY(..)</code>. Example\: <code>create table test(id int primary key, name varchar(255), key idx_name(name));</code> 
features_1499_li=Meta data calls return identifiers in lower case. 
features_1500_li=When converting a floating point number to an integer, the fractional digits are not truncated, but the value is rounded. 
features_1501_li=Concatenating <code>NULL</code> with another value results in the other value. 
features_1502_p=\ Text comparison in MySQL is case insensitive by default, while in H2 it is case sensitive (as in most other databases). H2 does support case insensitive text comparison, but it needs to be set separately, using <code>SET IGNORECASE TRUE</code>. This affects comparison using <code>\=, LIKE, REGEXP</code>. 
features_1503_h3=Oracle Compatibility Mode
features_1504_p=\ To use the Oracle mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=Oracle</code> or the SQL statement <code>SET MODE Oracle</code>. 
features_1505_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1506_li=When using unique indexes, multiple rows with <code>NULL</code> in all columns are allowed, however it is not allowed to have multiple rows with the same values otherwise. 
features_1507_li=Concatenating <code>NULL</code> with another value results in the other value. 
features_1508_li=Empty strings are treated like <code>NULL</code> values. 
features_1509_h3=PostgreSQL Compatibility Mode
features_1510_p=\ To use the PostgreSQL mode, use the database URL <code>jdbc\:h2\:~/test;MODE\=PostgreSQL</code> or the SQL statement <code>SET MODE PostgreSQL</code>. 
features_1511_li=For aliased columns, <code>ResultSetMetaData.getColumnName()</code> returns the alias name and <code>getTableName()</code> returns <code>null</code>. 
features_1512_li=When converting a floating point number to an integer, the fractional digits are not be truncated, but the value is rounded. 
features_1513_li=The system columns <code>CTID</code> and <code>OID</code> are supported. 
features_1514_li=LOG(x) is base 10 in this mode. 
features_1515_h2=Auto-Reconnect
features_1516_p=\ The auto-reconnect feature causes the JDBC driver to reconnect to the database if the connection is lost. The automatic re-connect only occurs when auto-commit is enabled; if auto-commit is disabled, an exception is thrown. To enable this mode, append <code>;AUTO_RECONNECT\=TRUE</code> to the database URL. 
features_1517_p=\ Re-connecting will open a new session. After an automatic re-connect, variables and local temporary tables definitions (excluding data) are re-created. The contents of the system table <code>INFORMATION_SCHEMA.SESSION_STATE</code> contains all client side state that is re-created. 
features_1518_p=\ If another connection uses the database in exclusive mode (enabled using <code>SET EXCLUSIVE 1</code> or <code>SET EXCLUSIVE 2</code>), then this connection will try to re-connect until the exclusive mode ends. 
features_1519_h2=Automatic Mixed Mode
features_1520_p=\ Multiple processes can access the same database without having to start the server manually. To do that, append <code>;AUTO_SERVER\=TRUE</code> to the database URL. You can use the same database URL independent of whether the database is already open or not. This feature doesn't work with in-memory databases. Example database URL\: 
features_1521_p=\ Use the same URL for all connections to this database. Internally, when using this mode, the first connection to the database is made in embedded mode, and additionally a server is started internally (as a daemon thread). If the database is already open in another process, the server mode is used automatically. The IP address and port of the server are stored in the file <code>.lock.db</code>, that's why in-memory databases can't be supported. 
features_1522_p=\ The application that opens the first connection to the database uses the embedded mode, which is faster than the server mode. Therefore the main application should open the database first if possible. The first connection automatically starts a server on a random port. This server allows remote connections, however only to this database (to ensure that, the client reads <code>.lock.db</code> file and sends the the random key that is stored there to the server). When the first connection is closed, the server stops. If other (remote) connections are still open, one of them will then start a server (auto-reconnect is enabled automatically). 
features_1523_p=\ All processes need to have access to the database files. If the first connection is closed (the connection that started the server), open transactions of other connections will be rolled back (this may not be a problem if you don't disable autocommit). Explicit client/server connections (using <code>jdbc\:h2\:tcp\://</code> or <code>ssl\://</code>) are not supported. This mode is not supported for in-memory databases. 
features_1524_p=\ Here is an example how to use this mode. Application 1 and 2 are not necessarily started on the same computer, but they need to have access to the database files. Application 1 and 2 are typically two different processes (however they could run within the same process). 
features_1525_p=\ When using this feature, by default the server uses any free TCP port. The port can be set manually using <code>AUTO_SERVER_PORT\=9090</code>. 
features_1526_h2=Page Size
features_1527_p=\ The page size for new databases is 2 KB (2048), unless the page size is set explicitly in the database URL using <code>PAGE_SIZE\=</code> when the database is created. The page size of existing databases can not be changed, so this property needs to be set when the database is created. 
features_1528_h2=Using the Trace Options
features_1529_p=\ To find problems in an application, it is sometimes good to see what database operations where executed. This database offers the following trace features\: 
features_1530_li=Trace to <code>System.out</code> and/or to a file 
features_1531_li=Support for trace levels <code>OFF, ERROR, INFO, DEBUG</code> 
features_1532_li=The maximum size of the trace file can be set 
features_1533_li=It is possible to generate Java source code from the trace file 
features_1534_li=Trace can be enabled at runtime by manually creating a file 
features_1535_h3=Trace Options
features_1536_p=\ The simplest way to enable the trace option is setting it in the database URL. There are two settings, one for <code>System.out</code> (<code>TRACE_LEVEL_SYSTEM_OUT</code>) tracing, and one for file tracing (<code>TRACE_LEVEL_FILE</code>). The trace levels are 0 for <code>OFF</code>, 1 for <code>ERROR</code> (the default), 2 for <code>INFO</code>, and 3 for <code>DEBUG</code>. A database URL with both levels set to <code>DEBUG</code> is\: 
features_1537_p=\ The trace level can be changed at runtime by executing the SQL command <code>SET TRACE_LEVEL_SYSTEM_OUT level</code> (for <code>System.out</code> tracing) or <code>SET TRACE_LEVEL_FILE level</code> (for file tracing). Example\: 
features_1538_h3=Setting the Maximum Size of the Trace File
features_1539_p=\ When using a high trace level, the trace file can get very big quickly. The default size limit is 16 MB, if the trace file exceeds this limit, it is renamed to <code>.old</code> and a new file is created. If another such file exists, it is deleted. To limit the size to a certain number of megabytes, use <code>SET TRACE_MAX_FILE_SIZE mb</code>. Example\: 
features_1540_h3=Java Code Generation
features_1541_p=\ When setting the trace level to <code>INFO</code> or <code>DEBUG</code>, Java source code is generated as well. This simplifies reproducing problems. The trace file looks like this\: 
features_1542_p=\ To filter the Java source code, use the <code>ConvertTraceFile</code> tool as follows\: 
features_1543_p=\ The generated file <code>Test.java</code> will contain the Java source code. The generated source code may be too large to compile (the size of a Java method is limited). If this is the case, the source code needs to be split in multiple methods. The password is not listed in the trace file and therefore not included in the source code. 
features_1544_h2=Using Other Logging APIs
features_1545_p=\ By default, this database uses its own native 'trace' facility. This facility is called 'trace' and not 'log' within this database to avoid confusion with the transaction log. Trace messages can be written to both file and <code>System.out</code>. In most cases, this is sufficient, however sometimes it is better to use the same facility as the application, for example Log4j. To do that, this database support SLF4J. 
features_1546_a=SLF4J
features_1547_p=\ is a simple facade for various logging APIs and allows to plug in the desired implementation at deployment time. SLF4J supports implementations such as Logback, Log4j, Jakarta Commons Logging (JCL), Java logging, x4juli, and Simple Log. 
features_1548_p=\ To enable SLF4J, set the file trace level to 4 in the database URL\: 
features_1549_p=\ Changing the log mechanism is not possible after the database is open, that means executing the SQL statement <code>SET TRACE_LEVEL_FILE 4</code> when the database is already open will not have the desired effect. To use SLF4J, all required jar files need to be in the classpath. The logger name is <code>h2database</code>. If it does not work, check the file <code>&lt;database&gt;.trace.db</code> for error messages. 
features_1550_h2=Read Only Databases
features_1551_p=\ If the database files are read-only, then the database is read-only as well. It is not possible to create new tables, add or modify data in this database. Only <code>SELECT</code> and <code>CALL</code> statements are allowed. To create a read-only database, close the database. Then, make the database file read-only. When you open the database now, it is read-only. There are two ways an application can find out whether database is read-only\: by calling <code>Connection.isReadOnly()</code> or by executing the SQL statement <code>CALL READONLY()</code>. 
features_1552_p=\ Using the <a href\="\#custom_access_mode">Custom Access Mode</a> <code>r</code> the database can also be opened in read-only mode, even if the database file is not read only. 
features_1553_h2=Read Only Databases in Zip or Jar File
features_1554_p=\ To create a read-only database in a zip file, first create a regular persistent database, and then create a backup. The database must not have pending changes, that means you need to close all connections to the database first. To speed up opening the read-only database and running queries, the database should be closed using <code>SHUTDOWN DEFRAG</code>. If you are using a database named <code>test</code>, an easy way to create a zip file is using the <code>Backup</code> tool. You can start the tool from the command line, or from within the H2 Console (Tools - Backup). Please note that the database must be closed when the backup is created. Therefore, the SQL statement <code>BACKUP TO</code> can not be used. 
features_1555_p=\ When the zip file is created, you can open the database in the zip file using the following database URL\: 
features_1556_p=\ Databases in zip files are read-only. The performance for some queries will be slower than when using a regular database, because random access in zip files is not supported (only streaming). How much this affects the performance depends on the queries and the data. The database is not read in memory; therefore large databases are supported as well. The same indexes are used as when using a regular database. 
features_1557_p=\ If the database is larger than a few megabytes, performance is much better if the database file is split into multiple smaller files, because random access in compressed files is not possible. See also the sample application <a href\="http\://code.google.com/p/h2database/source/browse/trunk/h2/src/test/org/h2/samples/ReadOnlyDatabaseInZip.java">ReadOnlyDatabaseInZip</a>. 
features_1558_h3=Opening a Corrupted Database
features_1559_p=\ If a database cannot be opened because the boot info (the SQL script that is run at startup) is corrupted, then the database can be opened by specifying a database event listener. The exceptions are logged, but opening the database will continue. 
features_1560_h2=Computed Columns / Function Based Index
features_1561_p=\ A computed column is a column whose value is calculated before storing. The formula is evaluated when the row is inserted, and re-evaluated every time the row is updated. One use case is to automatically update the last-modification time\: 
features_1562_p=\ Function indexes are not directly supported by this database, but they can be emulated by using computed columns. For example, if an index on the upper-case version of a column is required, create a computed column with the upper-case version of the original column, and create an index for this column\: 
features_1563_p=\ When inserting data, it is not required (and not allowed) to specify a value for the upper-case version of the column, because the value is generated. But you can use the column when querying the table\: 
features_1564_h2=Multi-Dimensional Indexes
features_1565_p=\ A tool is provided to execute efficient multi-dimension (spatial) range queries. This database does not support a specialized spatial index (R-Tree or similar). Instead, the B-Tree index is used. For each record, the multi-dimensional key is converted (mapped) to a single dimensional (scalar) value. This value specifies the location on a space-filling curve. 
features_1566_p=\ Currently, Z-order (also called N-order or Morton-order) is used; Hilbert curve could also be used, but the implementation is more complex. The algorithm to convert the multi-dimensional value is called bit-interleaving. The scalar value is indexed using a B-Tree index (usually using a computed column). 
features_1567_p=\ The method can result in a drastic performance improvement over just using an index on the first column. Depending on the data and number of dimensions, the improvement is usually higher than factor 5. The tool generates a SQL query from a specified multi-dimensional range. The method used is not database dependent, and the tool can easily be ported to other databases. For an example how to use the tool, please have a look at the sample code provided in <code>TestMultiDimension.java</code>. 
features_1568_h2=User-Defined Functions and Stored Procedures
features_1569_p=\ In addition to the built-in functions, this database supports user-defined Java functions. In this database, Java functions can be used as stored procedures as well. A function must be declared (registered) before it can be used. A function can be defined using source code, or as a reference to a compiled class that is available in the classpath. By default, the function aliases are stored in the current schema. 
features_1570_h3=Referencing a Compiled Method
features_1571_p=\ When referencing a method, the class must already be compiled and included in the classpath where the database is running. Only static Java methods are supported; both the class and the method must be public. Example Java class\: 
features_1572_p=\ The Java function must be registered in the database by calling <code>CREATE ALIAS ... FOR</code>\: 
features_1573_p=\ For a complete sample application, see <code>src/test/org/h2/samples/Function.java</code>. 
features_1574_h3=Declaring Functions as Source Code
features_1575_p=\ When defining a function alias with source code, the database tries to compile the source code using the Sun Java compiler (the class <code>com.sun.tools.javac.Main</code>) if the <code>tools.jar</code> is in the classpath. If not, <code>javac</code> is run as a separate process. Only the source code is stored in the database; the class is compiled each time the database is re-opened. Source code is usually passed as dollar quoted text to avoid escaping problems, however single quotes can be used as well. Example\: 
features_1576_p=\ By default, the three packages <code>java.util, java.math, java.sql</code> are imported. The method name (<code>nextPrime</code> in the example above) is ignored. Method overloading is not supported when declaring functions as source code, that means only one method may be declared for an alias. If different import statements are required, they must be declared at the beginning and separated with the tag <code>@CODE</code>\: 
features_1577_p=\ The following template is used to create a complete Java class\: 
features_1578_h3=Method Overloading
features_1579_p=\ Multiple methods may be bound to a SQL function if the class is already compiled and included in the classpath. Each Java method must have a different number of arguments. Method overloading is not supported when declaring functions as source code. 
features_1580_h3=Function Data Type Mapping
features_1581_p=\ Functions that accept non-nullable parameters such as <code>int</code> will not be called if one of those parameters is <code>NULL</code>. Instead, the result of the function is <code>NULL</code>. If the function should be called if a parameter is <code>NULL</code>, you need to use <code>java.lang.Integer</code> instead. 
features_1582_p=\ SQL types are mapped to Java classes and vice-versa as in the JDBC API. For details, see <a href\="datatypes.html">Data Types</a>. There are a few special cases\: <code>java.lang.Object</code> is mapped to <code>OTHER</code> (a serialized object). Therefore, <code>java.lang.Object</code> can not be used to match all SQL types (matching all SQL types is not supported). The second special case is <code>Object[]</code>\: arrays of any class are mapped to <code>ARRAY</code>. Objects of type <code>org.h2.value.Value</code> (the internal value class) are passed through without conversion. 
features_1583_h3=Functions That Require a Connection
features_1584_p=\ If the first parameter of a Java function is a <code>java.sql.Connection</code>, then the connection to database is provided. This connection does not need to be closed before returning. When calling the method from within the SQL statement, this connection parameter does not need to be (can not be) specified. 
features_1585_h3=Functions Throwing an Exception
features_1586_p=\ If a function throws an exception, then the current statement is rolled back and the exception is thrown to the application. SQLException are directly re-thrown to the calling application; all other exceptions are first converted to a SQLException. 
features_1587_h3=Functions Returning a Result Set
features_1588_p=\ Functions may returns a result set. Such a function can be called with the <code>CALL</code> statement\: 
features_1589_h3=Using SimpleResultSet
features_1590_p=\ A function can create a result set using the <code>SimpleResultSet</code> tool\: 
features_1591_h3=Using a Function as a Table
features_1592_p=\ A function that returns a result set can be used like a table. However, in this case the function is called at least twice\: first while parsing the statement to collect the column names (with parameters set to <code>null</code> where not known at compile time). And then, while executing the statement to get the data (maybe multiple times if this is a join). If the function is called just to get the column list, the URL of the connection passed to the function is <code>jdbc\:columnlist\:connection</code>. Otherwise, the URL of the connection is <code>jdbc\:default\:connection</code>. 
features_1593_h2=Pluggable or User-Defined Tables
features_1594_p=\ For situations where you need to expose other data-sources to the SQL engine as a table, there are "pluggable tables". For some examples, have a look at the code in <code>org.h2.test.db.TestTableEngines</code>. 
features_1595_p=\ In order to create your own TableEngine, you need to implement the <code>org.h2.api.TableEngine</code> interface e.g. something like this\: 
features_1596_p=\ and then create the table from SQL like this\: 
features_1597_p=\ It is also possible to pass in parameters to the table engine, like so\: 
features_1598_p=\ In which case the parameters are passed down in the tableEngineParams field of the CreateTableData object. 
features_1599_h2=Triggers
features_1600_p=\ This database supports Java triggers that are called before or after a row is updated, inserted or deleted. Triggers can be used for complex consistency checks, or to update related data in the database. It is also possible to use triggers to simulate materialized views. For a complete sample application, see <code>src/test/org/h2/samples/TriggerSample.java</code>. A Java trigger must implement the interface <code>org.h2.api.Trigger</code>. The trigger class must be available in the classpath of the database engine (when using the server mode, it must be in the classpath of the server). 
features_1601_p=\ The connection can be used to query or update data in other tables. The trigger then needs to be defined in the database\: 
features_1602_p=\ The trigger can be used to veto a change by throwing a <code>SQLException</code>. 
features_1603_p=\ As an alternative to implementing the <code>Trigger</code> interface, an application can extend the abstract class <code>org.h2.tools.TriggerAdapter</code>. This will allows to use the <code>ResultSet</code> interface within trigger implementations. In this case, only the <code>fire</code> method needs to be implemented\: 
features_1604_h2=Compacting a Database
features_1605_p=\ Empty space in the database file re-used automatically. When closing the database, the database is automatically compacted for up to 200 milliseconds by default. To compact more, use the SQL statement SHUTDOWN COMPACT. However re-creating the database may further reduce the database size because this will re-build the indexes. Here is a sample function to do this\: 
features_1606_p=\ See also the sample application <code>org.h2.samples.Compact</code>. The commands <code>SCRIPT / RUNSCRIPT</code> can be used as well to create a backup of a database and re-build the database from the script. 
features_1607_h2=Cache Settings
features_1608_p=\ The database keeps most frequently used data in the main memory. The amount of memory used for caching can be changed using the setting <code>CACHE_SIZE</code>. This setting can be set in the database connection URL (<code>jdbc\:h2\:~/test;CACHE_SIZE\=131072</code>), or it can be changed at runtime using <code>SET CACHE_SIZE size</code>. The size of the cache, as represented by <code>CACHE_SIZE</code> is measured in KB, with each KB being 1024 bytes. This setting has no effect for in-memory databases. For persistent databases, the setting is stored in the database and re-used when the database is opened the next time. However, when opening an existing database, the cache size is set to at most half the amount of memory available for the virtual machine (Runtime.getRuntime().maxMemory()), even if the cache size setting stored in the database is larger; however the setting stored in the database is kept. Setting the cache size in the database URL or explicitly using <code>SET CACHE_SIZE</code> overrides this value (even if larger than the physical memory). To get the current used maximum cache size, use the query <code>SELECT * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME \= 'info.CACHE_MAX_SIZE'</code> 
features_1609_p=\ An experimental scan-resistant cache algorithm "Two Queue" (2Q) is available. To enable it, append <code>;CACHE_TYPE\=TQ</code> to the database URL. The cache might not actually improve performance. If you plan to use it, please run your own test cases first. 
features_1610_p=\ Also included is an experimental second level soft reference cache. Rows in this cache are only garbage collected on low memory. By default the second level cache is disabled. To enable it, use the prefix <code>SOFT_</code>. Example\: <code>jdbc\:h2\:~/test;CACHE_TYPE\=SOFT_LRU</code>. The cache might not actually improve performance. If you plan to use it, please run your own test cases first. 
features_1611_p=\ To get information about page reads and writes, and the current caching algorithm in use, call <code>SELECT * FROM INFORMATION_SCHEMA.SETTINGS</code>. The number of pages read / written is listed. 
fragments_1000_div=\ &nbsp;&nbsp;<span id \= "goTop" onclick\="window.scrollTo(0,0)" style\="color\: \#fff; position\:fixed; font-size\: 20px; cursor\: pointer;">&\#x25b2;</span> 
fragments_1001_label=Search\:
fragments_1002_label=Highlight keyword(s)
fragments_1003_a=Home
fragments_1004_a=Download
fragments_1005_a=Cheat Sheet
fragments_1006_b=Documentation
fragments_1007_a=Quickstart
fragments_1008_a=Installation
fragments_1009_a=Tutorial
fragments_1010_a=Features
fragments_1011_a=Performance
fragments_1012_a=Advanced
fragments_1013_b=Reference
fragments_1014_a=SQL Grammar
fragments_1015_a=Functions
fragments_1016_a=Data Types
fragments_1017_a=Javadoc
fragments_1018_a=PDF (1 MB)
fragments_1019_b=Support
fragments_1020_a=FAQ
fragments_1021_a=Error Analyzer
fragments_1022_a=Google Group (English)
fragments_1023_a=Google Group (Japanese)
fragments_1024_a=Google Group (Chinese)
fragments_1025_b=Appendix
fragments_1026_a=History &amp; Roadmap
fragments_1027_a=License
fragments_1028_a=Build
fragments_1029_a=Links
fragments_1030_a=JaQu
fragments_1031_a=MVStore
fragments_1032_a=Architecture
fragments_1033_td=&nbsp;
frame_1000_h1=H2 Database Engine
frame_1001_p=\ Welcome to H2, the free SQL database. The main feature of H2 are\: 
frame_1002_li=It is free to use for everybody, source code is included 
frame_1003_li=Written in Java, but also available as native executable 
frame_1004_li=JDBC and (partial) ODBC API 
frame_1005_li=Embedded and client/server modes 
frame_1006_li=Clustering is supported 
frame_1007_li=A web client is included 
frame_1008_h2=No Javascript
frame_1009_p=\ If you are not automatically redirected to the main page, then Javascript is currently disabled or your browser does not support Javascript. Some features (for example the integrated search) require Javascript. 
frame_1010_p=\ Please enable Javascript, or go ahead without it\: <a href\="main.html" style\="font-size\: 16px; font-weight\: bold">H2 Database Engine</a> 
history_1000_h1=History and Roadmap
history_1001_a=\ Change Log
history_1002_a=\ Roadmap
history_1003_a=\ History of this Database Engine
history_1004_a=\ Why Java
history_1005_a=\ Supporters
history_1006_h2=Change Log
history_1007_p=\ The up-to-date change log is available at <a href\="http\://www.h2database.com/html/changelog.html"> http\://www.h2database.com/html/changelog.html </a> 
history_1008_h2=Roadmap
history_1009_p=\ The current roadmap is available at <a href\="http\://www.h2database.com/html/roadmap.html"> http\://www.h2database.com/html/roadmap.html </a> 
history_1010_h2=History of this Database Engine
history_1011_p=\ The development of H2 was started in May 2004, but it was first published on December 14th 2005. The main author of H2, Thomas Mueller, is also the original developer of Hypersonic SQL. In 2001, he joined PointBase Inc. where he wrote PointBase Micro, a commercial Java SQL database. At that point, he had to discontinue Hypersonic SQL. The HSQLDB Group was formed to continued to work on the Hypersonic SQL codebase. The name H2 stands for Hypersonic 2, however H2 does not share code with Hypersonic SQL or HSQLDB. H2 is built from scratch. 
history_1012_h2=Why Java
history_1013_p=\ The main reasons to use a Java database are\: 
history_1014_li=Very simple to integrate in Java applications 
history_1015_li=Support for many different platforms 
history_1016_li=More secure than native applications (no buffer overflows) 
history_1017_li=User defined functions (or triggers) run very fast 
history_1018_li=Unicode support 
history_1019_p=\ Some think Java is too slow for low level operations, but this is no longer true. Garbage collection for example is now faster than manual memory management. 
history_1020_p=\ Developing Java code is faster than developing C or C++ code. When using Java, most time can be spent on improving the algorithms instead of porting the code to different platforms or doing memory management. Features such as Unicode and network libraries are already built-in. In Java, writing secure code is easier because buffer overflows can not occur. Features such as reflection can be used for randomized testing. 
history_1021_p=\ Java is future proof\: a lot of companies support Java. Java is now open source. 
history_1022_p=\ To increase the portability and ease of use, this software depends on very few libraries. Features that are not available in open source Java implementations (such as Swing) are not used, or only used for optional features. 
history_1023_h2=Supporters
history_1024_p=\ Many thanks for those who reported bugs, gave valuable feedback, spread the word, and translated this project. Also many thanks to the donors\: 
history_1025_a=Code 42 Software, Inc., Minneapolis
history_1026_li=Martin Wildam, Austria 
history_1027_a=Code Lutin, France
history_1028_a=NetSuxxess GmbH, Germany
history_1029_a=Poker Copilot, Steve McLeod, Germany
history_1030_a=SkyCash, Poland
history_1031_a=Lumber-mill, Inc., Japan
history_1032_a=StockMarketEye, USA
history_1033_a=Eckenfelder GmbH & Co.KG, Germany
history_1034_li=Anthony Goubard, Netherlands 
history_1035_li=Richard Hickey, USA 
history_1036_li=Alessio Jacopo D'Adamo, Italy 
history_1037_li=Ashwin Jayaprakash, USA 
history_1038_li=Donald Bleyl, USA 
history_1039_li=Frank Berger, Germany 
history_1040_li=Florent Ramiere, France 
history_1041_li=Jun Iyama, Japan 
history_1042_li=Antonio Casqueiro, Portugal 
history_1043_li=Oliver Computing LLC, USA 
history_1044_li=Harpal Grover Consulting Inc., USA 
history_1045_li=Elisabetta Berlini, Italy 
history_1046_li=William Gilbert, USA 
history_1047_li=Antonio Dieguez Rojas, Chile 
history_1048_a=Ontology Works, USA
history_1049_li=Pete Haidinyak, USA 
history_1050_li=William Osmond, USA 
history_1051_li=Joachim Ansorg, Germany 
history_1052_li=Oliver Soerensen, Germany 
history_1053_li=Christos Vasilakis, Greece 
history_1054_li=Fyodor Kupolov, Denmark 
history_1055_li=Jakob Jenkov, Denmark 
history_1056_li=St&eacute;phane Chartrand, Switzerland 
history_1057_li=Glenn Kidd, USA 
history_1058_li=Gustav Trede, Sweden 
history_1059_li=Joonas Pulakka, Finland 
history_1060_li=Bjorn Darri Sigurdsson, Iceland 
history_1061_li=Iyama Jun, Japan 
history_1062_li=Gray Watson, USA 
history_1063_li=Erik Dick, Germany 
history_1064_li=Pengxiang Shao, China 
history_1065_li=Bilingual Marketing Group, USA 
history_1066_li=Philippe Marschall, Switzerland 
history_1067_li=Knut Staring, Norway 
history_1068_li=Theis Borg, Denmark 
history_1069_li=Mark De Mendonca Duske, USA 
history_1070_li=Joel A. Garringer, USA 
history_1071_li=Olivier Chafik, France 
history_1072_li=Rene Schwietzke, Germany 
history_1073_li=Jalpesh Patadia, USA 
history_1074_li=Takanori Kawashima, Japan 
history_1075_li=Terrence JC Huang, China 
history_1076_a=JiaDong Huang, Australia
history_1077_li=Laurent van Roy, Belgium 
history_1078_li=Qian Chen, China 
history_1079_li=Clinton Hyde, USA 
history_1080_li=Kritchai Phromros, Thailand 
installation_1000_h1=Installation
installation_1001_a=\ Requirements
installation_1002_a=\ Supported Platforms
installation_1003_a=\ Installing the Software
installation_1004_a=\ Directory Structure
installation_1005_h2=Requirements
installation_1006_p=\ To run this database, the following software stack is known to work. Other software most likely also works, but is not tested as much. 
installation_1007_h3=Database Engine
installation_1008_li=Windows XP or Vista, Mac OS X, or Linux 
installation_1009_li=Sun Java 6 or newer 
installation_1010_li=Recommended Windows file system\: NTFS (FAT32 only supports files up to 4 GB) 
installation_1011_h3=H2 Console
installation_1012_li=Mozilla Firefox 
installation_1013_h2=Supported Platforms
installation_1014_p=\ As this database is written in Java, it can run on many different platforms. It is tested with Java 6 and 7. Currently, the database is developed and tested on Windows 8 and Mac OS X using Java 6, but it also works in many other operating systems and using other Java runtime environments. All major operating systems (Windows XP, Windows Vista, Windows 7, Mac OS, Ubuntu,...) are supported. 
installation_1015_h2=Installing the Software
installation_1016_p=\ To install the software, run the installer or unzip it to a directory of your choice. 
installation_1017_h2=Directory Structure
installation_1018_p=\ After installing, you should get the following directory structure\: 
installation_1019_th=Directory
installation_1020_th=Contents
installation_1021_td=bin
installation_1022_td=JAR and batch files
installation_1023_td=docs
installation_1024_td=Documentation
installation_1025_td=docs/html
installation_1026_td=HTML pages
installation_1027_td=docs/javadoc
installation_1028_td=Javadoc files
installation_1029_td=ext
installation_1030_td=External dependencies (downloaded when building)
installation_1031_td=service
installation_1032_td=Tools to run the database as a Windows Service
installation_1033_td=src
installation_1034_td=Source files
installation_1035_td=src/docsrc
installation_1036_td=Documentation sources
installation_1037_td=src/installer
installation_1038_td=Installer, shell, and release build script
installation_1039_td=src/main
installation_1040_td=Database engine source code
installation_1041_td=src/test
installation_1042_td=Test source code
installation_1043_td=src/tools
installation_1044_td=Tools and database adapters source code
jaqu_1000_h1=JaQu
jaqu_1001_a=\ What is JaQu
jaqu_1002_a=\ Differences to Other Data Access Tools
jaqu_1003_a=\ Current State
jaqu_1004_a=\ Building the JaQu Library
jaqu_1005_a=\ Requirements
jaqu_1006_a=\ Example Code
jaqu_1007_a=\ Configuration
jaqu_1008_a=\ Natural Syntax
jaqu_1009_a=\ Other Ideas
jaqu_1010_a=\ Similar Projects
jaqu_1011_h2=What is JaQu
jaqu_1012_p=\ Note\: This project is currently in maintenance mode. A friendly fork of JaQu is <a href\="http\://iciql.com">available under the name iciql</a>. 
jaqu_1013_p=\ JaQu stands for Java Query and allows to access databases using pure Java. JaQu provides a fluent interface (or internal DSL). JaQu is something like LINQ for Java (LINQ stands for "language integrated query" and is a Microsoft .NET technology). The following JaQu code\: 
jaqu_1014_p=\ stands for the SQL statement\: 
jaqu_1015_h2=Differences to Other Data Access Tools
jaqu_1016_p=\ Unlike SQL, JaQu can be easily integrated in Java applications. Because JaQu is pure Java, auto-complete in the IDE is supported. Type checking is performed by the compiler. JaQu fully protects against SQL injection. 
jaqu_1017_p=\ JaQu is meant as replacement for JDBC and SQL and not as much as a replacement for tools like Hibernate. With JaQu, you don't write SQL statements as strings. JaQu is much smaller and simpler than other persistence frameworks such as Hibernate, but it also does not provide all the features of those. Unlike iBatis and Hibernate, no XML or annotation based configuration is required; instead the configuration (if required at all) is done in pure Java, within the application. 
jaqu_1018_p=\ JaQu does not require or contain any data caching mechanism. Like JDBC and iBatis, JaQu provides full control over when and what SQL statements are executed (but without having to write SQL statements as strings). 
jaqu_1019_h3=Restrictions
jaqu_1020_p=\ Primitive types (eg. <code>boolean, int, long, double</code>) are not supported. Use <code>java.lang.Boolean, Integer, Long, Double</code> instead. 
jaqu_1021_h3=Why in Java?
jaqu_1022_p=\ Most applications are written in Java. Mixing Java and another language (for example Scala or Groovy) in the same application is complicated\: you would need to split the application and database code, and write adapter / wrapper code. 
jaqu_1023_h2=Current State
jaqu_1024_p=\ Currently, JaQu is only tested with the H2 database. The API may change in future versions. JaQu is not part of the h2 jar file, however the source code is included in H2, under\: 
jaqu_1025_code=src/test/org/h2/test/jaqu/*
jaqu_1026_li=\ (samples and tests) 
jaqu_1027_code=src/tools/org/h2/jaqu/*
jaqu_1028_li=\ (framework) 
jaqu_1029_h2=Building the JaQu Library
jaqu_1030_p=\ To create the JaQu jar file, run\: <code>build jarJaqu</code>. This will create the file <code>bin/h2jaqu.jar</code>. 
jaqu_1031_h2=Requirements
jaqu_1032_p=\ JaQu requires Java 6. Annotations are not need. Currently, JaQu is only tested with the H2 database engine, however in theory it should work with any database that supports the JDBC API. 
jaqu_1033_h2=Example Code
jaqu_1034_h2=Configuration
jaqu_1035_p=\ JaQu does not require any configuration when using the default field to column mapping. To define table indices, or if you want to map a class to a table with a different name, or a field to a column with another name, create a function called <code>define</code> in the data class. Example\: 
jaqu_1036_p=\ The method <code>define()</code> contains the mapping definition. It is called once when the class is used for the first time. Like annotations, the mapping is defined in the class itself. Unlike when using annotations, the compiler can check the syntax even for multi-column objects (multi-column indexes, multi-column primary keys and so on). Because the definition is written in Java, the configuration can be set at runtime, which is not possible using annotations. Unlike XML mapping configuration, the configuration is integrated in the class itself. 
jaqu_1037_h2=Natural Syntax
jaqu_1038_p=The plan is to support more natural (pure Java) syntax in conditions. To do that, the condition class is de-compiled to a SQL condition. A proof of concept decompiler is included (but it doesn't fully work yet; patches are welcome). The planned syntax is\: 
jaqu_1039_h2=Other Ideas
jaqu_1040_p=\ This project has just been started, and nothing is fixed yet. Some ideas are\: 
jaqu_1041_li=Support queries on collections (instead of using a database). 
jaqu_1042_li=Provide API level compatibility with JPA (so that JaQu can be used as an extension of JPA). 
jaqu_1043_li=Internally use a JPA implementation (for example Hibernate) instead of SQL directly. 
jaqu_1044_li=Use PreparedStatements and cache them. 
jaqu_1045_h2=Similar Projects
jaqu_1046_a=iciql (a friendly fork of JaQu)
jaqu_1047_a=Cement Framework
jaqu_1048_a=Dreamsource ORM
jaqu_1049_a=Empire-db
jaqu_1050_a=JEQUEL\: Java Embedded QUEry Language
jaqu_1051_a=Joist
jaqu_1052_a=jOOQ
jaqu_1053_a=JoSQL
jaqu_1054_a=LIQUidFORM
jaqu_1055_a=Quaere (Alias implementation)
jaqu_1056_a=Quaere
jaqu_1057_a=Querydsl
jaqu_1058_a=Squill
license_1000_h1=License
license_1001_a=\ Summary and License FAQ
license_1002_a=\ H2 License - Version 1.0
license_1003_a=\ Eclipse Public License - Version 1.0
license_1004_a=\ Export Control Classification Number (ECCN)
license_1005_h2=Summary and License FAQ
license_1006_p=\ H2 is dual licensed and available under a modified version of the MPL 1.1 (<a href\="http\://www.mozilla.org/MPL">Mozilla Public License</a>) or under the (unmodified) EPL 1.0 (<a href\="http\://opensource.org/licenses/eclipse-1.0.php">Eclipse Public License</a>). The changes to the MPL are 
license_1007_em=underlined</em>. There is a license FAQ for both the MPL and the EPL, most of that is applicable to the H2 license as well. 
license_1008_li=You can use H2 for free. You can integrate it into your applications (including in commercial applications), and you can distribute it. 
license_1009_li=Files containing only your code are not covered by this license (it is 'commercial friendly'). 
license_1010_li=Modifications to the H2 source code must be published. 
license_1011_li=You don't need to provide the source code of H2 if you did not modify anything. 
license_1012_li=If you distribute a binary that includes H2, you need to add a disclaimer of liability - see the example below. 
license_1013_p=\ However, nobody is allowed to rename H2, modify it a little, and sell it as a database engine without telling the customers it is in fact H2. This happened to HSQLDB\: a company called 'bungisoft' copied HSQLDB, renamed it to 'RedBase', and tried to sell it, hiding the fact that it was in fact just HSQLDB. It seems 'bungisoft' does not exist any more, but you can use the <a href\="http\://www.archive.org">Wayback Machine</a> and visit old web pages of <code>http\://www.bungisoft.com</code>. 
license_1014_p=\ About porting the source code to another language (for example C\# or C++)\: converted source code (even if done manually) stays under the same copyright and license as the original code. The copyright of the ported source code does not (automatically) go to the person who ported the code. 
license_1015_p=\ If you distribute a binary that includes H2, you need to add the license and a disclaimer of liability (as you should do for your own code). You should add a disclaimer for each open source libraries you use. For example, add a file <code>3rdparty_license.txt</code> in the directory where the jar files are, and list all open source libraries, each one with its license and disclaimer. For H2, a simple solution is to copy the following text below. You may also include a copy of the complete license. 
license_1016_h2=H2 License - Version 1.0
license_1017_h3=1. Definitions
license_1018_b=1.0.1. "Commercial Use"
license_1019_p=\ means distribution or otherwise making the Covered Code available to a third party. 
license_1020_b=1.1. "Contributor"
license_1021_p=\ means each entity that creates or contributes to the creation of Modifications. 
license_1022_b=1.2. "Contributor Version"
license_1023_p=\ means the combination of the Original Code, prior Modifications used by a Contributor, and the Modifications made by that particular Contributor. 
license_1024_b=1.3. "Covered Code"
license_1025_p=\ means the Original Code or Modifications or the combination of the Original Code and Modifications, in each case including portions thereof. 
license_1026_b=1.4. "Electronic Distribution Mechanism"
license_1027_p=\ means a mechanism generally accepted in the software development community for the electronic transfer of data. 
license_1028_b=1.5. "Executable"
license_1029_p=\ means Covered Code in any form other than Source Code. 
license_1030_b=1.6. "Initial Developer"
license_1031_p=\ means the individual or entity identified as the Initial Developer in the Source Code notice required by <a href\="\#exhibit-a">Exhibit A</a>. 
license_1032_b=1.7. "Larger Work"
license_1033_p=\ means a work which combines Covered Code or portions thereof with code not governed by the terms of this License. 
license_1034_b=1.8. "License"
license_1035_p=\ means this document. 
license_1036_b=1.8.1. "Licensable"
license_1037_p=\ means having the right to grant, to the maximum extent possible, whether at the time of the initial grant or subsequently acquired, any and all of the rights conveyed herein. 
license_1038_b=1.9. "Modifications"
license_1039_p=\ means any addition to or deletion from the substance or structure of either the Original Code or any previous Modifications. When Covered Code is released as a series of files, a Modification is\: 
license_1040_p=1.9.a. Any addition to or deletion from the contents of a file containing Original Code or previous Modifications. 
license_1041_p=1.9.b. Any new file that contains any part of the Original Code or previous Modifications. 
license_1042_b=1.10. "Original Code"
license_1043_p=\ means Source Code of computer software code which is described in the Source Code notice required by <a href\="\#exhibit-a">Exhibit A</a> as Original Code, and which, at the time of its release under this License is not already Covered Code governed by this License. 
license_1044_b=1.10.1. "Patent Claims"
license_1045_p=\ means any patent claim(s), now owned or hereafter acquired, including without limitation, method, process, and apparatus claims, in any patent Licensable by grantor. 
license_1046_b=1.11. "Source Code"
license_1047_p=\ means the preferred form of the Covered Code for making modifications to it, including all modules it contains, plus any associated interface definition files, scripts used to control compilation and installation of an Executable, or source code differential comparisons against either the Original Code or another well known, available Covered Code of the Contributor's choice. The Source Code can be in a compressed or archival form, provided the appropriate decompression or de-archiving software is widely available for no charge. 
license_1048_b=1.12. "You" (or "Your")
license_1049_p=\ means an individual or a legal entity exercising rights under, and complying with all of the terms of, this License or a future version of this License issued under <a href\="\#section-6.1">Section 6.1.</a> For legal entities, "You" includes any entity which controls, is controlled by, or is under common control with You. For purposes of this definition, "control" means (a) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (b) ownership of more than fifty percent (50%) of the outstanding shares or beneficial ownership of such entity. 
license_1050_h3=2. Source Code License
license_1051_h4=2.1. The Initial Developer Grant
license_1052_p=\ The Initial Developer hereby grants You a world-wide, royalty-free, non-exclusive license, subject to third party intellectual property claims\: 
license_1053_p=2.1.a. under intellectual property rights (other than patent or trademark) Licensable by Initial Developer to use, reproduce, modify, display, perform, sublicense and distribute the Original Code (or portions thereof) with or without Modifications, and/or as part of a Larger Work; and 
license_1054_p=2.1.b. under Patents Claims infringed by the making, using or selling of Original Code, to make, have made, use, practice, sell, and offer for sale, and/or otherwise dispose of the Original Code (or portions thereof). 
license_1055_p=2.1.c. the licenses granted in this Section 2.1 (<a href\="\#section-2.1-a">a</a>) and (<a href\="\#section-2.1-b">b</a>) are effective on the date Initial Developer first distributes Original Code under the terms of this License. 
license_1056_p=2.1.d. Notwithstanding Section 2.1 (<a href\="\#section-2.1-b">b</a>) above, no patent license is granted\: 1) for code that You delete from the Original Code; 2) separate from the Original Code; or 3) for infringements caused by\: i) the modification of the Original Code or ii) the combination of the Original Code with other software or devices. 
license_1057_h4=2.2. Contributor Grant
license_1058_p=\ Subject to third party intellectual property claims, each Contributor hereby grants You a world-wide, royalty-free, non-exclusive license 
license_1059_p=2.2.a. under intellectual property rights (other than patent or trademark) Licensable by Contributor, to use, reproduce, modify, display, perform, sublicense and distribute the Modifications created by such Contributor (or portions thereof) either on an unmodified basis, with other Modifications, as Covered Code and/or as part of a Larger Work; and 
license_1060_p=2.2.b. under Patent Claims infringed by the making, using, or selling of Modifications made by that Contributor either alone and/or in combination with its Contributor Version (or portions of such combination), to make, use, sell, offer for sale, have made, and/or otherwise dispose of\: 1) Modifications made by that Contributor (or portions thereof); and 2) the combination of Modifications made by that Contributor with its Contributor Version (or portions of such combination). 
license_1061_p=2.2.c. the licenses granted in Sections 2.2 (<a href\="\#section-2.2-a">a</a>) and 2.2 (<a href\="\#section-2.2-b">b</a>) are effective on the date Contributor first makes Commercial Use of the Covered Code. 
license_1062_p=2.2.c. Notwithstanding Section 2.2 (<a href\="\#section-2.2-b">b</a>) above, no patent license is granted\: 1) for any code that Contributor has deleted from the Contributor Version; 2) separate from the Contributor Version; 3) for infringements caused by\: i) third party modifications of Contributor Version or ii) the combination of Modifications made by that Contributor with other software (except as part of the Contributor Version) or other devices; or 4) under Patent Claims infringed by Covered Code in the absence of Modifications made by that Contributor. 
license_1063_h3=3. Distribution Obligations
license_1064_h4=3.1. Application of License
license_1065_p=\ The Modifications which You create or to which You contribute are governed by the terms of this License, including without limitation Section <a href\="\#section-2.2">2.2</a>. The Source Code version of Covered Code may be distributed only under the terms of this License or a future version of this License released under Section <a href\="\#section-6.1">6.1</a>, and You must include a copy of this License with every copy of the Source Code You distribute. You may not offer or impose any terms on any Source Code version that alters or restricts the applicable version of this License or the recipients' rights hereunder. However, You may include an additional document offering the additional rights described in Section <a href\="\#section-3.5">3.5</a>. 
license_1066_h4=3.2. Availability of Source Code
license_1067_p=\ Any Modification which You create or to which You contribute must be made available in Source Code form under the terms of this License either on the same media as an Executable version or via an accepted Electronic Distribution Mechanism to anyone to whom you made an Executable version available; and if made available via Electronic Distribution Mechanism, must remain available for at least twelve (12) months after the date it initially became available, or at least six (6) months after a subsequent version of that particular Modification has been made available to such recipients. You are responsible for ensuring that the Source Code version remains available even if the Electronic Distribution Mechanism is maintained by a third party. 
license_1068_h4=3.3. Description of Modifications
license_1069_p=\ You must cause all Covered Code to which You contribute to contain a file documenting the changes You made to create that Covered Code and the date of any change. You must include a prominent statement that the Modification is derived, directly or indirectly, from Original Code provided by the Initial Developer and including the name of the Initial Developer in (a) the Source Code, and (b) in any notice in an Executable version or related documentation in which You describe the origin or ownership of the Covered Code. 
license_1070_h4=3.4. Intellectual Property Matters
license_1071_b=3.4.a. Third Party Claims\:
license_1072_p=\ If Contributor has knowledge that a license under a third party's intellectual property rights is required to exercise the rights granted by such Contributor under Sections <a href\="\#section-2.1">2.1</a> or <a href\="\#section-2.2">2.2</a>, Contributor must include a text file with the Source Code distribution titled "LEGAL" which describes the claim and the party making the claim in sufficient detail that a recipient will know whom to contact. If Contributor obtains such knowledge after the Modification is made available as described in Section <a href\="\#section-3.2">3.2</a>, Contributor shall promptly modify the LEGAL file in all copies Contributor makes available thereafter and shall take other steps (such as notifying appropriate mailing lists or newsgroups) reasonably calculated to inform those who received the Covered Code that new knowledge has been obtained. 
license_1073_b=3.4.b. Contributor APIs\:
license_1074_p=\ If Contributor's Modifications include an application programming interface and Contributor has knowledge of patent licenses which are reasonably necessary to implement that API, Contributor must also include this information in the legal file. 
license_1075_b=3.4.c. Representations\:
license_1076_p=\ Contributor represents that, except as disclosed pursuant to Section 3.4 (<a href\="\#section-3.4-a">a</a>) above, Contributor believes that Contributor's Modifications are Contributor's original creation(s) and/or Contributor has sufficient rights to grant the rights conveyed by this License. 
license_1077_h4=3.5. Required Notices
license_1078_p=\ You must duplicate the notice in <a href\="\#exhibit-a">Exhibit A</a> in each file of the Source Code. If it is not possible to put such notice in a particular Source Code file due to its structure, then You must include such notice in a location (such as a relevant directory) where a user would be likely to look for such a notice. If You created one or more Modification(s) You may add your name as a Contributor to the notice described in <a href\="\#exhibit-a">Exhibit A</a>. You must also duplicate this License in any documentation for the Source Code where You describe recipients' rights or ownership rights relating to Covered Code. You may choose to offer, and to charge a fee for, warranty, support, indemnity or liability obligations to one or more recipients of Covered Code. However, You may do so only on Your own behalf, and not on behalf of the Initial Developer or any Contributor. You must make it absolutely clear than any such warranty, support, indemnity or liability obligation is offered by You alone, and You hereby agree to indemnify the Initial Developer and every Contributor for any liability incurred by the Initial Developer or such Contributor as a result of warranty, support, indemnity or liability terms You offer. 
license_1079_h4=3.6. Distribution of Executable Versions
license_1080_p=\ You may distribute Covered Code in Executable form only if the requirements of Sections <a href\="\#section-3.1">3.1</a>, <a href\="\#section-3.2">3.2</a>, <a href\="\#section-3.3">3.3</a>, <a href\="\#section-3.4">3.4</a> and <a href\="\#section-3.5">3.5</a> have been met for that Covered Code, and if You include a notice stating that the Source Code version of the Covered Code is available under the terms of this License, including a description of how and where You have fulfilled the obligations of Section <a href\="\#section-3.2">3.2</a>. The notice must be conspicuously included in any notice in an Executable version, related documentation or collateral in which You describe recipients' rights relating to the Covered Code. You may distribute the Executable version of Covered Code or ownership rights under a license of Your choice, which may contain terms different from this License, provided that You are in compliance with the terms of this License and that the license for the Executable version does not attempt to limit or alter the recipient's rights in the Source Code version from the rights set forth in this License. If You distribute the Executable version under a different license You must make it absolutely clear that any terms which differ from this License are offered by You alone, not by the Initial Developer or any Contributor. You hereby agree to indemnify the Initial Developer and every Contributor for any liability incurred by the Initial Developer or such Contributor as a result of any such terms You offer. 
license_1081_h4=3.7. Larger Works
license_1082_p=\ You may create a Larger Work by combining Covered Code with other code not governed by the terms of this License and distribute the Larger Work as a single product. In such a case, You must make sure the requirements of this License are fulfilled for the Covered Code. 
license_1083_h3=4. Inability to Comply Due to Statute or Regulation.
license_1084_p=\ If it is impossible for You to comply with any of the terms of this License with respect to some or all of the Covered Code due to statute, judicial order, or regulation then You must\: (a) comply with the terms of this License to the maximum extent possible; and (b) describe the limitations and the code they affect. Such description must be included in the <b>legal</b> file described in Section <a href\="\#section-3.4">3.4</a> and must be included with all distributions of the Source Code. Except to the extent prohibited by statute or regulation, such description must be sufficiently detailed for a recipient of ordinary skill to be able to understand it. 
license_1085_h3=5. Application of this License.
license_1086_p=\ This License applies to code to which the Initial Developer has attached the notice in <a href\="\#exhibit-a">Exhibit A</a> and to related Covered Code. 
license_1087_h3=6. Versions of the License.
license_1088_h4=6.1. New Versions
license_1089_p=\ The 
license_1090_em=H2 Group</em> may publish revised and/or new versions of the License from time to time. Each version will be given a distinguishing version number. 
license_1091_h4=6.2. Effect of New Versions
license_1092_p=\ Once Covered Code has been published under a particular version of the License, You may always continue to use it under the terms of that version. You may also choose to use such Covered Code under the terms of any subsequent version of the License published by the 
license_1093_em=H2 Group</em>. No one other than the 
license_1094_em=H2 Group</em> has the right to modify the terms applicable to Covered Code created under this License. 
license_1095_h4=6.3. Derivative Works
license_1096_p=\ If You create or use a modified version of this License (which you may only do in order to apply it to code which is not already Covered Code governed by this License), You must (a) rename Your license so that the phrases 
license_1097_em="H2 Group", "H2"</em> or any confusingly similar phrase do not appear in your license (except to note that your license differs from this License) and (b) otherwise make it clear that Your version of the license contains terms which differ from the 
license_1098_em=H2 License</em>. (Filling in the name of the Initial Developer, Original Code or Contributor in the notice described in <a href\="\#exhibit-a">Exhibit A</a> shall not of themselves be deemed to be modifications of this License.) 
license_1099_h3=7. Disclaimer of Warranty
license_1100_p=\ Covered code is provided under this license on an "as is" basis, without warranty of any kind, either expressed or implied, including, without limitation, warranties that the covered code is free of defects, merchantable, fit for a particular purpose or non-infringing. The entire risk as to the quality and performance of the covered code is with you. Should any covered code prove defective in any respect, you (not the initial developer or any other contributor) assume the cost of any necessary servicing, repair or correction. This disclaimer of warranty constitutes an essential part of this license. No use of any covered code is authorized hereunder except under this disclaimer. 
license_1101_h3=8. Termination
license_1102_p=8.1. This License and the rights granted hereunder will terminate automatically if You fail to comply with terms herein and fail to cure such breach within 30 days of becoming aware of the breach. All sublicenses to the Covered Code which are properly granted shall survive any termination of this License. Provisions which, by their nature, must remain in effect beyond the termination of this License shall survive. 
license_1103_p=8.2. If You initiate litigation by asserting a patent infringement claim (excluding declaratory judgment actions) against Initial Developer or a Contributor (the Initial Developer or Contributor against whom You file such action is referred to as "Participant") alleging that\: 
license_1104_p=8.2.a. such Participant's Contributor Version directly or indirectly infringes any patent, then any and all rights granted by such Participant to You under Sections <a href\="\#section-2.1">2.1</a> and/or <a href\="\#section-2.2">2.2</a> of this License shall, upon 60 days notice from Participant terminate prospectively, unless if within 60 days after receipt of notice You either\: (i) agree in writing to pay Participant a mutually agreeable reasonable royalty for Your past and future use of Modifications made by such Participant, or (ii) withdraw Your litigation claim with respect to the Contributor Version against such Participant. If within 60 days of notice, a reasonable royalty and payment arrangement are not mutually agreed upon in writing by the parties or the litigation claim is not withdrawn, the rights granted by Participant to You under Sections <a href\="\#section-2.1">2.1</a> and/or <a href\="\#section-2.2">2.2</a> automatically terminate at the expiration of the 60 day notice period specified above. 
license_1105_p=8.2.b. any software, hardware, or device, other than such Participant's Contributor Version, directly or indirectly infringes any patent, then any rights granted to You by such Participant under Sections 2.1(<a href\="\#section-2.1-b">b</a>) and 2.2(<a href\="\#section-2.2-b">b</a>) are revoked effective as of the date You first made, used, sold, distributed, or had made, Modifications made by that Participant. 
license_1106_p=8.3. If You assert a patent infringement claim against Participant alleging that such Participant's Contributor Version directly or indirectly infringes any patent where such claim is resolved (such as by license or settlement) prior to the initiation of patent infringement litigation, then the reasonable value of the licenses granted by such Participant under Sections <a href\="\#section-2.1">2.1</a> or <a href\="\#section-2.2">2.2</a> shall be taken into account in determining the amount or value of any payment or license. 
license_1107_p=8.4. In the event of termination under Sections <a href\="\#section-8.1">8.1</a> or <a href\="\#section-8.2">8.2</a> above, all end user license agreements (excluding distributors and resellers) which have been validly granted by You or any distributor hereunder prior to termination shall survive termination. 
license_1108_h3=9. Limitation of Liability
license_1109_p=\ Under no circumstances and under no legal theory, whether tort (including negligence), contract, or otherwise, shall you, the initial developer, any other contributor, or any distributor of covered code, or any supplier of any of such parties, be liable to any person for any indirect, special, incidental, or consequential damages of any character including, without limitation, damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses, even if such party shall have been informed of the possibility of such damages. This limitation of liability shall not apply to liability for death or personal injury resulting from such party's negligence to the extent applicable law prohibits such limitation. Some jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so this exclusion and limitation may not apply to you. 
license_1110_h3=10. United States Government End Users
license_1111_p=\ The Covered Code is a "commercial item", as that term is defined in 48 C.F.R. 2.101 (October 1995), consisting of "commercial computer software" and "commercial computer software documentation", as such terms are used in 48 C.F.R. 12.212 (September 1995). Consistent with 48 C.F.R. 12.212 and 48 C.F.R. 227.7202-1 through 227.7202-4 (June 1995), all U.S. Government End Users acquire Covered Code with only those rights set forth herein. 
license_1112_h3=11. Miscellaneous
license_1113_p=\ This License represents the complete agreement concerning subject matter hereof. If any provision of this License is held to be unenforceable, such provision shall be reformed only to the extent necessary to make it enforceable. This License shall be governed by California law provisions (except to the extent applicable law, if any, provides otherwise), excluding its conflict-of-law provisions. With respect to disputes in which at least one party is a citizen of, or an entity chartered or registered to do business in United States of America, any litigation relating to this License shall be subject to the jurisdiction of the Federal Courts of the Northern District of California, with venue lying in Santa Clara County, California, with the losing party responsible for costs, including without limitation, court costs and reasonable attorneys' fees and expenses. The application of the United Nations Convention on Contracts for the International Sale of Goods is expressly excluded. Any law or regulation which provides that the language of a contract shall be construed against the drafter shall not apply to this License. 
license_1114_h3=12. Responsibility for Claims
license_1115_p=\ As between Initial Developer and the Contributors, each party is responsible for claims and damages arising, directly or indirectly, out of its utilization of rights under this License and You agree to work with Initial Developer and Contributors to distribute such responsibility on an equitable basis. Nothing herein is intended or shall be deemed to constitute any admission of liability. 
license_1116_h3=13. Multiple-Licensed Code
license_1117_p=\ Initial Developer may designate portions of the Covered Code as "Multiple-Licensed". "Multiple-Licensed" means that the Initial Developer permits you to utilize portions of the Covered Code under Your choice of this or the alternative licenses, if any, specified by the Initial Developer in the file described in <a href\="\#exhibit-a">Exhibit A</a>. 
license_1118_h3=Exhibit A
license_1119_h2=Eclipse Public License - Version 1.0
license_1120_p=\ THE ACCOMPANYING PROGRAM IS PROVIDED UNDER THE TERMS OF THIS ECLIPSE PUBLIC LICENSE ("AGREEMENT"). ANY USE, REPRODUCTION OR DISTRIBUTION OF THE PROGRAM CONSTITUTES RECIPIENT'S ACCEPTANCE OF THIS AGREEMENT. 
license_1121_h3=1. DEFINITIONS
license_1122_p=\ "Contribution" means\: 
license_1123_p=\ a) in the case of the initial Contributor, the initial code and documentation distributed under this Agreement, and 
license_1124_p=\ b) in the case of each subsequent Contributor\: 
license_1125_p=\ i) changes to the Program, and 
license_1126_p=\ ii) additions to the Program; 
license_1127_p=\ where such changes and/or additions to the Program originate from and are distributed by that particular Contributor. A Contribution 'originates' from a Contributor if it was added to the Program by such Contributor itself or anyone acting on such Contributor's behalf. Contributions do not include additions to the Program which\: (i) are separate modules of software distributed in conjunction with the Program under their own license agreement, and (ii) are not derivative works of the Program. 
license_1128_p=\ "Contributor" means any person or entity that distributes the Program. 
license_1129_p=\ "Licensed Patents " mean patent claims licensable by a Contributor which are necessarily infringed by the use or sale of its Contribution alone or when combined with the Program. 
license_1130_p=\ "Program" means the Contributions distributed in accordance with this Agreement. 
license_1131_p=\ "Recipient" means anyone who receives the Program under this Agreement, including all Contributors. 
license_1132_h3=2. GRANT OF RIGHTS
license_1133_p=\ a) Subject to the terms of this Agreement, each Contributor hereby grants Recipient a non-exclusive, worldwide, royalty-free copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, distribute and sublicense the Contribution of such Contributor, if any, and such derivative works, in source code and object code form. 
license_1134_p=\ b) Subject to the terms of this Agreement, each Contributor hereby grants Recipient a non-exclusive, worldwide, royalty-free patent license under Licensed Patents to make, use, sell, offer to sell, import and otherwise transfer the Contribution of such Contributor, if any, in source code and object code form. This patent license shall apply to the combination of the Contribution and the Program if, at the time the Contribution is added by the Contributor, such addition of the Contribution causes such combination to be covered by the Licensed Patents. The patent license shall not apply to any other combinations which include the Contribution. No hardware per se is licensed hereunder. 
license_1135_p=\ c) Recipient understands that although each Contributor grants the licenses to its Contributions set forth herein, no assurances are provided by any Contributor that the Program does not infringe the patent or other intellectual property rights of any other entity. Each Contributor disclaims any liability to Recipient for claims brought by any other entity based on infringement of intellectual property rights or otherwise. As a condition to exercising the rights and licenses granted hereunder, each Recipient hereby assumes sole responsibility to secure any other intellectual property rights needed, if any. For example, if a third party patent license is required to allow Recipient to distribute the Program, it is Recipient's responsibility to acquire that license before distributing the Program. 
license_1136_p=\ d) Each Contributor represents that to its knowledge it has sufficient copyright rights in its Contribution, if any, to grant the copyright license set forth in this Agreement. 
license_1137_h3=3. REQUIREMENTS
license_1138_p=\ A Contributor may choose to distribute the Program in object code form under its own license agreement, provided that\: 
license_1139_p=\ a) it complies with the terms and conditions of this Agreement; and 
license_1140_p=\ b) its license agreement\: 
license_1141_p=\ i) effectively disclaims on behalf of all Contributors all warranties and conditions, express and implied, including warranties or conditions of title and non-infringement, and implied warranties or conditions of merchantability and fitness for a particular purpose; 
license_1142_p=\ ii) effectively excludes on behalf of all Contributors all liability for damages, including direct, indirect, special, incidental and consequential damages, such as lost profits; 
license_1143_p=\ iii) states that any provisions which differ from this Agreement are offered by that Contributor alone and not by any other party; and 
license_1144_p=\ iv) states that source code for the Program is available from such Contributor, and informs licensees how to obtain it in a reasonable manner on or through a medium customarily used for software exchange. 
license_1145_p=\ When the Program is made available in source code form\: 
license_1146_p=\ a) it must be made available under this Agreement; and 
license_1147_p=\ b) a copy of this Agreement must be included with each copy of the Program. 
license_1148_p=\ Contributors may not remove or alter any copyright notices contained within the Program. 
license_1149_p=\ Each Contributor must identify itself as the originator of its Contribution, if any, in a manner that reasonably allows subsequent Recipients to identify the originator of the Contribution. 
license_1150_h3=4. COMMERCIAL DISTRIBUTION
license_1151_p=\ Commercial distributors of software may accept certain responsibilities with respect to end users, business partners and the like. While this license is intended to facilitate the commercial use of the Program, the Contributor who includes the Program in a commercial product offering should do so in a manner which does not create potential liability for other Contributors. Therefore, if a Contributor includes the Program in a commercial product offering, such Contributor ("Commercial Contributor") hereby agrees to defend and indemnify every other Contributor ("Indemnified Contributor") against any losses, damages and costs (collectively "Losses") arising from claims, lawsuits and other legal actions brought by a third party against the Indemnified Contributor to the extent caused by the acts or omissions of such Commercial Contributor in connection with its distribution of the Program in a commercial product offering. The obligations in this section do not apply to any claims or Losses relating to any actual or alleged intellectual property infringement. In order to qualify, an Indemnified Contributor must\: a) promptly notify the Commercial Contributor in writing of such claim, and b) allow the Commercial Contributor to control, and cooperate with the Commercial Contributor in, the defense and any related settlement negotiations. The Indemnified Contributor may participate in any such claim at its own expense. 
license_1152_p=\ For example, a Contributor might include the Program in a commercial product offering, Product X. That Contributor is then a Commercial Contributor. If that Commercial Contributor then makes performance claims, or offers warranties related to Product X, those performance claims and warranties are such Commercial Contributor's responsibility alone. Under this section, the Commercial Contributor would have to defend claims against the other Contributors related to those performance claims and warranties, and if a court requires any other Contributor to pay any damages as a result, the Commercial Contributor must pay those damages. 
license_1153_h3=5. NO WARRANTY
license_1154_p=\ EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is solely responsible for determining the appropriateness of using and distributing the Program and assumes all risks associated with its exercise of rights under this Agreement, including but not limited to the risks and costs of program errors, compliance with applicable laws, damage to or loss of data, programs or equipment, and unavailability or interruption of operations. 
license_1155_h3=6. DISCLAIMER OF LIABILITY
license_1156_p=\ EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 
license_1157_h3=7. GENERAL
license_1158_p=\ If any provision of this Agreement is invalid or unenforceable under applicable law, it shall not affect the validity or enforceability of the remainder of the terms of this Agreement, and without further action by the parties hereto, such provision shall be reformed to the minimum extent necessary to make such provision valid and enforceable. 
license_1159_p=\ If Recipient institutes patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Program itself (excluding combinations of the Program with other software or hardware) infringes such Recipient's patent(s), then such Recipient's rights granted under Section 2(b) shall terminate as of the date such litigation is filed. 
license_1160_p=\ All Recipient's rights under this Agreement shall terminate if it fails to comply with any of the material terms or conditions of this Agreement and does not cure such failure in a reasonable period of time after becoming aware of such noncompliance. If all Recipient's rights under this Agreement terminate, Recipient agrees to cease use and distribution of the Program as soon as reasonably practicable. However, Recipient's obligations under this Agreement and any licenses granted by Recipient relating to the Program shall continue and survive. 
license_1161_p=\ Everyone is permitted to copy and distribute copies of this Agreement, but in order to avoid inconsistency the Agreement is copyrighted and may only be modified in the following manner. The Agreement Steward reserves the right to publish new versions (including revisions) of this Agreement from time to time. No one other than the Agreement Steward has the right to modify this Agreement. The Eclipse Foundation is the initial Agreement Steward. The Eclipse Foundation may assign the responsibility to serve as the Agreement Steward to a suitable separate entity. Each new version of the Agreement will be given a distinguishing version number. The Program (including Contributions) may always be distributed subject to the version of the Agreement under which it was received. In addition, after a new version of the Agreement is published, Contributor may elect to distribute the Program (including its Contributions) under the new version. Except as expressly stated in Sections 2(a) and 2(b) above, Recipient receives no rights or licenses to the intellectual property of any Contributor under this Agreement, whether expressly, by implication, estoppel or otherwise. All rights in the Program not expressly granted under this Agreement are reserved. 
license_1162_p=\ This Agreement is governed by the laws of the State of New York and the intellectual property laws of the United States of America. No party to this Agreement will bring a legal action under this Agreement more than one year after the cause of action arose. Each party waives its rights to a jury trial in any resulting litigation. 
license_1163_h2=Export Control Classification Number (ECCN)
license_1164_p=\ As far as we know, the <a href\="http\://www.bis.doc.gov/licensing/exportingbasics.htm">U.S. Export Control Classification Number (ECCN)</a> for this software is <code>5D002</code>. However, for legal reasons, we can make no warranty that this information is correct. For details, see also the <a href\="http\://www.apache.org/licenses/exports/">Apache Software Foundation Export Classifications page</a>. 
links_1000_h1=Links
links_1001_p=\ If you want to add a link, please send it to the support email address or post it to the group. 
links_1002_a=\ Commercial Support
links_1003_a=\ Quotes
links_1004_a=\ Books
links_1005_a=\ Extensions
links_1006_a=\ Blog Articles, Videos
links_1007_a=\ Database Frontends / Tools
links_1008_a=\ Products and Projects
links_1009_h2=Commercial Support
links_1010_a=Commercial support for H2 is available
links_1011_p=\ from Steve McLeod (steve dot mcleod at gmail dot com). Please note he is not one of the main developers of H2. He describes himself as follows\: 
links_1012_li=I'm a long time user of H2, routinely working with H2 databases several gigabytes in size. 
links_1013_li=I'm the creator of popular commercial desktop software that uses H2. 
links_1014_li=I'm a certified Java developer (SCJP). 
links_1015_li=I have a decade and more of IT consulting experience with large and small clients in Australia, the UK, and Germany. 
links_1016_li=I'm based in Germany, and willing to travel within Europe. I can work remotely with teams in the USA and other locations." 
links_1017_h2=Quotes
links_1018_a=\ Quote
links_1019_p=\: "This is by far the easiest and fastest database that I have ever used. Originally the web application that I am working on is using SQL server. But, in less than 15 minutes I had H2 up and working with little recoding of the SQL. Thanks..... " 
links_1020_h2=Books
links_1021_a=\ Seam In Action
links_1022_h2=Extensions
links_1023_a=\ Grails H2 Database Plugin
links_1024_a=\ h2osgi\: OSGi for the H2 Database
links_1025_a=\ H2Sharp\: ADO.NET interface for the H2 database engine
links_1026_a=\ H2 Spatial\: spatial functions to H2 database
links_1027_h2=Blog Articles, Videos
links_1028_a=\ Youtube\: Minecraft 1.7.3 / How to install Bukkit Server with xAuth and H2
links_1029_a=\ Analyzing CSVs with H2 in under 10 minutes (2009-12-07)
links_1030_a=\ Efficient sorting and iteration on large databases (2009-06-15)
links_1031_a=\ Porting Flexive to the H2 Database (2008-12-05)
links_1032_a=\ H2 Database with GlassFish (2008-11-24)
links_1033_a=\ Using H2 Database with Glassfish and Toplink (2008-08-07)
links_1034_a=\ H2 Database - Performance Tracing (2008-04-30)
links_1035_a=\ Testing your JDBC data access layer with DBUnit and H2 (2007-09-18)
links_1036_a=\ Open Source Databases Comparison (2007-09-11)
links_1037_a=\ The Codist\: The Open Source Frameworks I Use (2007-07-23)
links_1038_a=\ The Codist\: SQL Injections\: How Not To Get Stuck (2007-05-08)
links_1039_a=\ One Man Band\: (Helma + H2) \=\= "to easy" (2007-03-11)
links_1040_a=\ David Coldrick's Weblog\: New Version of H2 Database Released (2007-01-06)
links_1041_a=\ The Codist\: Write Your Own Database, Again (2006-11-13)
links_1042_h2=Project Pages
links_1043_a=\ Ohloh
links_1044_a=\ Freshmeat Project Page
links_1045_a=\ Free Open Source Software For Us
links_1046_a=\ Wikipedia
links_1047_a=\ Java Source Net
links_1048_a=\ Linux Package Manager
links_1049_h2=Database Frontends / Tools
links_1050_a=\ Dataflyer
links_1051_p=\ A tool to browse databases and export data. 
links_1052_a=\ DB Solo
links_1053_p=\ SQL query tool. 
links_1054_a=\ DbVisualizer
links_1055_p=\ Database tool. 
links_1056_a=\ Execute Query
links_1057_p=\ Database utility written in Java. 
links_1058_a=\ Flyway
links_1059_p=\ The agile database migration framework for Java. 
links_1060_a=\ [fleXive]
links_1061_p=\ JavaEE 5 open source framework for the development of complex and evolving (web-)applications. 
links_1062_a=\ HenPlus
links_1063_p=\ HenPlus is a SQL shell written in Java. 
links_1064_a=\ JDBC lint
links_1065_p=\ Helps write correct and efficient code when using the JDBC API. 
links_1066_a=\ OpenOffice
links_1067_p=\ Base is OpenOffice.org's database application. It provides access to relational data sources. 
links_1068_a=\ RazorSQL
links_1069_p=\ An SQL query tool, database browser, SQL editor, and database administration tool. 
links_1070_a=\ SQL Developer
links_1071_p=\ Universal Database Frontend. 
links_1072_a=\ SQL Workbench/J
links_1073_p=\ Free DBMS-independent SQL tool. 
links_1074_a=\ SQuirreL SQL Client
links_1075_p=\ Graphical tool to view the structure of a database, browse the data, issue SQL commands etc. 
links_1076_a=\ SQuirreL DB Copy Plugin
links_1077_p=\ Tool to copy data from one database to another. 
links_1078_h2=Products and Projects
links_1079_a=\ AccuProcess
links_1080_p=\ Visual business process modeling and simulation software for business users. 
links_1081_a=\ Adeptia BPM
links_1082_p=\ A Business Process Management (BPM) suite to quickly and easily automate business processes and workflows. 
links_1083_a=\ Adeptia Integration
links_1084_p=\ Process-centric, services-based application integration suite. 
links_1085_a=\ Aejaks
links_1086_p=\ A server-side scripting environment to build AJAX enabled web applications. 
links_1087_a=\ Axiom Stack
links_1088_p=\ A web framework that let's you write dynamic web applications with Zen-like simplicity. 
links_1089_a=\ Apache Cayenne
links_1090_p=\ Open source persistence framework providing object-relational mapping (ORM) and remoting services. 
links_1091_a=\ Apache Jackrabbit
links_1092_p=\ Open source implementation of the Java Content Repository API (JCR). 
links_1093_a=\ Apache OpenJPA
links_1094_p=\ Open source implementation of the Java Persistence API (JPA). 
links_1095_a=\ AppFuse
links_1096_p=\ Helps building web applications. 
links_1097_a=\ BGBlitz
links_1098_p=\ The Swiss army knife of Backgammon. 
links_1099_a=\ Blojsom
links_1100_p=\ Java-based multi-blog, multi-user software package (Mac OS X Weblog Server). 
links_1101_a=\ Bonita
links_1102_p=\ Open source workflow solution for handing long-running, user-oriented processes providing out of the box workflow and business process management features. 
links_1103_a=\ Bookmarks Portlet
links_1104_p=\ JSR 168 compliant bookmarks management portlet application. 
links_1105_a=\ Claros inTouch
links_1106_p=\ Ajax communication suite with mail, addresses, notes, IM, and rss reader. 
links_1107_a=\ CrashPlan PRO Server
links_1108_p=\ Easy and cross platform backup solution for business and service providers. 
links_1109_a=\ DbUnit
links_1110_p=\ A JUnit extension (also usable with Ant) targeted for database-driven projects. 
links_1111_a=\ DiffKit
links_1112_p=\ DiffKit is a tool for comparing two tables of data, field-by-field. DiffKit is like the Unix diff utility, but for tables instead of lines of text. 
links_1113_a=\ Dinamica Framework
links_1114_p=\ Ajax/J2EE framework for RAD development (mainly oriented toward hispanic markets). 
links_1115_a=\ District Health Information Software 2 (DHIS)
links_1116_p=\ The DHIS 2 is a tool for collection, validation, analysis, and presentation of aggregate statistical data, tailored (but not limited) to integrated health information management activities. 
links_1117_a=\ Ebean ORM Persistence Layer
links_1118_p=\ Open source Java Object Relational Mapping tool. 
links_1119_a=\ Eclipse CDO
links_1120_p=\ The CDO (Connected Data Objects) Model Repository is a distributed shared model framework for EMF models, and a fast server-based O/R mapping solution. 
links_1121_a=\ Epictetus
links_1122_p=\ Free cross platform database tool. 
links_1123_a=\ Fabric3
links_1124_p=\ Fabric3 is a project implementing a federated service network based on the Service Component Architecture specification (http\://www.osoa.org). 
links_1125_a=\ FIT4Data
links_1126_p=\ A testing framework for data management applications built on the Java implementation of FIT. 
links_1127_a=\ Flux
links_1128_p=\ Java job scheduler, file transfer, workflow, and BPM. 
links_1129_a=\ GeoServer
links_1130_p=\ GeoServer is a Java-based software server that allows users to view and edit geospatial data. Using open standards set forth by the Open Geospatial Consortium (OGC), GeoServer allows for great flexibility in map creation and data sharing. 
links_1131_a=\ GBIF Integrated Publishing Toolkit (IPT)
links_1132_p=\ The GBIF IPT is an open source, Java based web application that connects and serves three types of biodiversity data\: taxon primary occurrence data, taxon checklists and general resource metadata. 
links_1133_a=\ GNU Gluco Control
links_1134_p=\ Helps you to manage your diabetes. 
links_1135_a=\ Golden T Studios
links_1136_p=\ Fun-to-play games with a simple interface. 
links_1137_a=\ GridGain
links_1138_p=\ GridGain is easy to use Cloud Application Platform that enables development of highly scalable distributed Java and Scala applications that auto-scale on any grid or cloud infrastructure. 
links_1139_a=\ Group Session
links_1140_p=\ Open source web groupware. 
links_1141_a=\ HA-JDBC
links_1142_p=\ High-Availability JDBC\: A JDBC proxy that provides light-weight, transparent, fault tolerant clustering capability to any underlying JDBC driver. 
links_1143_a=\ Harbor
links_1144_p=\ Pojo Application Server. 
links_1145_a=\ Hibernate
links_1146_p=\ Relational persistence for idiomatic Java (O-R mapping tool). 
links_1147_a=\ Hibicius
links_1148_p=\ Online Banking Client for the HBCI protocol. 
links_1149_a=\ ImageMapper
links_1150_p=\ ImageMapper frees users from having to use file browsers to view their images. They get fast access to images and easy cataloguing of them via a user friendly interface. 
links_1151_a=\ JAMWiki
links_1152_p=\ Java-based Wiki engine. 
links_1153_a=\ Jala
links_1154_p=\ Open source collection of JavaScript modules. 
links_1155_a=\ Jaspa
links_1156_p=\ Java Spatial. Jaspa potentially brings around 200 spatial functions. 
links_1157_a=\ Java Simon
links_1158_p=\ Simple Monitoring API. 
links_1159_a=\ JBoss jBPM
links_1160_p=\ A platform for executable process languages ranging from business process management (BPM) over workflow to service orchestration. 
links_1161_a=\ JBoss Jopr
links_1162_p=\ An enterprise management solution for JBoss middleware projects and other application technologies. 
links_1163_a=\ JGeocoder
links_1164_p=\ Free Java geocoder. Geocoding is the process of estimating a latitude and longitude for a given location. 
links_1165_a=\ JGrass
links_1166_p=\ Java Geographic Resources Analysis Support System. Free, multi platform, open source GIS based on the GIS framework of uDig. 
links_1167_a=\ Jena
links_1168_p=\ Java framework for building Semantic Web applications. 
links_1169_a=\ JMatter
links_1170_p=\ Framework for constructing workgroup business applications based on the Naked Objects Architectural Pattern. 
links_1171_a=\ jOOQ (Java Object Oriented Querying)
links_1172_p=\ jOOQ is a fluent API for typesafe SQL query construction and execution 
links_1173_a=\ JotBot
links_1174_p=\ Records your day at user defined intervals. 
links_1175_a=\ JPOX
links_1176_p=\ Java persistent objects. 
links_1177_a=\ Liftweb
links_1178_p=\ A Scala-based, secure, developer friendly web framework. 
links_1179_a=\ LiquiBase
links_1180_p=\ A tool to manage database changes and refactorings. 
links_1181_a=\ Luntbuild
links_1182_p=\ Build automation and management tool. 
links_1183_a=\ localdb
links_1184_p=\ A tool that locates the full file path of the folder containing the database files. 
links_1185_a=\ Magnolia
links_1186_p=\ Microarray Data Management and Export System for PFGRC (Pathogen Functional Genomics Resource Center) Microarrays. 
links_1187_a=\ MiniConnectionPoolManager
links_1188_p=\ A lightweight standalone JDBC connection pool manager. 
links_1189_a=\ Mr. Persister
links_1190_p=\ Simple, small and fast object relational mapping. 
links_1191_a=\ Myna Application Server
links_1192_p=\ Java web app that provides dynamic web content and Java libraries access from JavaScript. 
links_1193_a=\ MyTunesRss
links_1194_p=\ MyTunesRSS lets you listen to your music wherever you are. 
links_1195_a=\ NCGC CurveFit
links_1196_p=\ From\: NIH Chemical Genomics Center, National Institutes of Health, USA. An open source application in the life sciences research field. This application handles chemical structures and biological responses of thousands of compounds with the potential to handle million+ compounds. It utilizes an embedded H2 database to enable flexible query/retrieval of all data including advanced chemical substructure and similarity searching. The application highlights an automated curve fitting and classification algorithm that outperforms commercial packages in the field. Commercial alternatives are typically small desktop software that handle a few dose response curves at a time. A couple of commercial packages that do handle several thousand curves are very expensive tools (&gt;60k USD) that require manual curation of analysis by the user; require a license to Oracle; lack advanced query/retrieval; and the ability to handle chemical structures. 
links_1197_a=\ Nuxeo
links_1198_p=\ Standards-based, open source platform for building ECM applications. 
links_1199_a=\ nWire
links_1200_p=\ Eclipse plug-in which expedites Java development. It's main purpose is to help developers find code quicker and easily understand how it relates to the rest of the application, thus, understand the application structure. 
links_1201_a=\ Ontology Works
links_1202_p=\ This company provides semantic technologies including deductive information repositories (the Ontology Works Knowledge Servers), semantic information fusion and semantic federation of legacy databases, ontology-based domain modeling, and management of the distributed enterprise. 
links_1203_a=\ Ontoprise OntoBroker
links_1204_p=\ SemanticWeb-Middleware. It supports all W3C Semantic Web recommendations\: OWL, RDF, RDFS, SPARQL, and F-Logic. 
links_1205_a=\ Open Anzo
links_1206_p=\ Semantic Application Server. 
links_1207_a=\ OpenTelegard
links_1208_p=\ An OpenSource BBS Software written in JRuby. 
links_1209_a=\ OpenGroove
links_1210_p=\ OpenGroove is a groupware program that allows users to synchronize data. 
links_1211_a=\ OpenSocial Development Environment (OSDE)
links_1212_p=\ Development tool for OpenSocial application. 
links_1213_a=\ Orion
links_1214_p=\ J2EE Application Server. 
links_1215_a=\ P5H2
links_1216_p=\ A library for the <a href\="http\://www.processing.org">Processing</a> programming language and environment. 
links_1217_a=\ Phase-6
links_1218_p=\ A computer based learning software. 
links_1219_a=\ Pickle
links_1220_p=\ Pickle is a Java library containing classes for persistence, concurrency, and logging. 
links_1221_a=\ Piman
links_1222_p=\ Water treatment projects data management. 
links_1223_a=\ PolePosition
links_1224_p=\ Open source database benchmark. 
links_1225_a=\ Poormans
links_1226_p=\ Very basic CMS running as a SWT application and generating static html pages. 
links_1227_a=\ Railo
links_1228_p=\ Railo is an alternative engine for the Cold Fusion Markup Language, that compiles code programmed in CFML into Java bytecode and executes it on a servlet engine. 
links_1229_a=\ Razuna
links_1230_p=\ Open source Digital Asset Management System with integrated Web Content Management. 
links_1231_a=\ RIFE
links_1232_p=\ A full-stack web application framework with tools and APIs to implement most common web features. 
links_1233_a=\ Rutema
links_1234_p=\ Rutema is a test execution and management tool for heterogeneous development environments written in Ruby. 
links_1235_a=\ Sava
links_1236_p=\ Open-source web-based content management system. 
links_1237_a=\ Scriptella
links_1238_p=\ ETL (Extract-Transform-Load) and script execution tool. 
links_1239_a=\ Sesar
links_1240_p=\ Dependency Injection Container with Aspect Oriented Programming. 
links_1241_a=\ SemmleCode
links_1242_p=\ Eclipse plugin to help you improve software quality. 
links_1243_a=\ SeQuaLite
links_1244_p=\ A free, light-weight, java data access framework. 
links_1245_a=\ ShapeLogic
links_1246_p=\ Toolkit for declarative programming, image processing and computer vision. 
links_1247_a=\ Shellbook
links_1248_p=\ Desktop publishing application. 
links_1249_a=\ Signsoft intelliBO
links_1250_p=\ Persistence middleware supporting the JDO specification. 
links_1251_a=\ SimpleORM
links_1252_p=\ Simple Java Object Relational Mapping. 
links_1253_a=\ SymmetricDS
links_1254_p=\ A web-enabled, database independent, data synchronization/replication software. 
links_1255_a=\ SmartFoxServer
links_1256_p=\ Platform for developing multiuser applications and games with Macromedia Flash. 
links_1257_a=\ Social Bookmarks Friend Finder
links_1258_p=\ A GUI application that allows you to find users with similar bookmarks to the user specified (for delicious.com). 
links_1259_a=\ sormula
links_1260_p=\ Simple object relational mapping. 
links_1261_a=\ Springfuse
links_1262_p=\ Code generation For Spring, Spring MVC &amp; Hibernate. 
links_1263_a=\ SQLOrm
links_1264_p=\ Java Object Relation Mapping. 
links_1265_a=\ StelsCSV and StelsXML
links_1266_p=\ StelsCSV is a CSV JDBC type 4 driver that allows to perform SQL queries and other JDBC operations on text files. StelsXML is a XML JDBC type 4 driver that allows to perform SQL queries and other JDBC operations on XML files. Both use H2 as the SQL engine. 
links_1267_a=\ StorYBook
links_1268_p=\ A summary-based tool for novelist and script writers. It helps to keep the overview over the various traces a story has. 
links_1269_a=\ StreamCruncher
links_1270_p=\ Event (stream) processing kernel. 
links_1271_a=\ SUSE Manager, part of Linux Enterprise Server 11
links_1272_p=\ The SUSE Manager <a href\="http\://www.suse.com/blogs/suse-manager-eases-the-buden-of-compliance"> eases the burden of compliance</a> with regulatory requirements and corporate policies. 
links_1273_a=\ Tune Backup
links_1274_p=\ Easy-to-use backup solution for your iTunes library. 
links_1275_a=\ weblica
links_1276_p=\ Desktop CMS. 
links_1277_a=\ Web of Web
links_1278_p=\ Collaborative and realtime interactive media platform for the web. 
links_1279_a=\ Werkzeugkasten
links_1280_p=\ Minimum Java Toolset. 
links_1281_a=\ VPDA
links_1282_p=\ View providers driven applications is a Java based application framework for building applications composed from server components - view providers. 
links_1283_a=\ Volunteer database
links_1284_p=\ A database front end to register volunteers, partnership and donation for a Non Profit organization. 
links_1285_a=\ 974 Application Server
links_1286_p=\ A clusterable application server. 
mainWeb_1000_h1=H2 Database Engine
mainWeb_1001_p=\ Welcome to H2, the Java SQL database. The main features of H2 are\: 
mainWeb_1002_li=Very fast, open source, JDBC API 
mainWeb_1003_li=Embedded and server modes; in-memory databases 
mainWeb_1004_li=Browser based Console application 
mainWeb_1005_li=Small footprint\: around 1.5 MB jar file size 
mainWeb_1006_h2=Download
mainWeb_1007_td=\ Version 1.4.178 (2014-05-02), Beta 
mainWeb_1008_a=Windows Installer (5 MB)
mainWeb_1009_a=All Platforms (zip, 8 MB)
mainWeb_1010_a=All Downloads
mainWeb_1011_td=&nbsp;&nbsp;&nbsp;
mainWeb_1012_h2=Support
mainWeb_1013_a=Stack Overflow (tag H2)
mainWeb_1014_a=Google Group English
mainWeb_1015_p=, <a href\="http\://groups.google.co.jp/group/h2-database-jp">Japanese</a>
mainWeb_1016_p=\ For non-technical issues, use\: 
mainWeb_1017_h2=Features
mainWeb_1018_th=H2
mainWeb_1019_a=Derby
mainWeb_1020_a=HSQLDB
mainWeb_1021_a=MySQL
mainWeb_1022_a=PostgreSQL
mainWeb_1023_td=Pure Java
mainWeb_1024_td=Yes
mainWeb_1025_td=Yes
mainWeb_1026_td=Yes
mainWeb_1027_td=No
mainWeb_1028_td=No
mainWeb_1029_td=Memory Mode
mainWeb_1030_td=Yes
mainWeb_1031_td=Yes
mainWeb_1032_td=Yes
mainWeb_1033_td=No
mainWeb_1034_td=No
mainWeb_1035_td=Encrypted Database
mainWeb_1036_td=Yes
mainWeb_1037_td=Yes
mainWeb_1038_td=Yes
mainWeb_1039_td=No
mainWeb_1040_td=No
mainWeb_1041_td=ODBC Driver
mainWeb_1042_td=Yes
mainWeb_1043_td=No
mainWeb_1044_td=No
mainWeb_1045_td=Yes
mainWeb_1046_td=Yes
mainWeb_1047_td=Fulltext Search
mainWeb_1048_td=Yes
mainWeb_1049_td=No
mainWeb_1050_td=No
mainWeb_1051_td=Yes
mainWeb_1052_td=Yes
mainWeb_1053_td=Multi Version Concurrency
mainWeb_1054_td=Yes
mainWeb_1055_td=No
mainWeb_1056_td=Yes
mainWeb_1057_td=Yes
mainWeb_1058_td=Yes
mainWeb_1059_td=Footprint (jar/dll size)
mainWeb_1060_td=~1 MB
mainWeb_1061_td=~2 MB
mainWeb_1062_td=~1 MB
mainWeb_1063_td=~4 MB
mainWeb_1064_td=~6 MB
mainWeb_1065_p=\ See also the <a href\="features.html\#comparison">detailed comparison</a>. 
mainWeb_1066_h2=News
mainWeb_1067_b=Newsfeeds\:
mainWeb_1068_a=Full text (Atom)
mainWeb_1069_p=\ or <a href\="http\://www.h2database.com/html/newsfeed-rss.xml">Header only (RSS)</a>. 
mainWeb_1070_b=Email Newsletter\:
mainWeb_1071_p=\ Subscribe to <a href\="http\://groups.google.com/group/h2database-news/subscribe"> H2 Database News (Google account required)</a> to get informed about new releases. Your email address is only used in this context. 
mainWeb_1072_td=&nbsp;
mainWeb_1073_h2=Contribute
mainWeb_1074_p=\ You can contribute to the development of H2 by sending feedback and bug reports, or translate the H2 Console application (for details, start the H2 Console and select Options / Translate). To donate money, click on the PayPal button below. You will be listed as a supporter\: 
main_1000_h1=H2 Database Engine
main_1001_p=\ Welcome to H2, the free Java SQL database engine. 
main_1002_a=Quickstart
main_1003_p=\ Get a fast overview. 
main_1004_a=Tutorial
main_1005_p=\ Go through the samples. 
main_1006_a=Features
main_1007_p=\ See what this database can do and how to use these features. 
mvstore_1000_h1=MVStore
mvstore_1001_a=\ Overview
mvstore_1002_a=\ Example Code
mvstore_1003_a=\ Store Builder
mvstore_1004_a=\ R-Tree
mvstore_1005_a=\ Features
mvstore_1006_a=- Maps
mvstore_1007_a=- Versions
mvstore_1008_a=- Transactions
mvstore_1009_a=- In-Memory Performance and Usage
mvstore_1010_a=- Pluggable Data Types
mvstore_1011_a=- BLOB Support
mvstore_1012_a=- R-Tree and Pluggable Map Implementations
mvstore_1013_a=- Concurrent Operations and Caching
mvstore_1014_a=- Log Structured Storage
mvstore_1015_a=- Off-Heap and Pluggable Storage
mvstore_1016_a=- File System Abstraction, File Locking and Online Backup
mvstore_1017_a=- Encrypted Files
mvstore_1018_a=- Tools
mvstore_1019_a=- Exception Handling
mvstore_1020_a=- Storage Engine for H2
mvstore_1021_a=\ File Format
mvstore_1022_a=\ Similar Projects and Differences to Other Storage Engines
mvstore_1023_a=\ Current State
mvstore_1024_a=\ Requirements
mvstore_1025_h2=Overview
mvstore_1026_p=\ The MVStore is work in progress, and is planned to be the next storage subsystem of H2. But it can also be used directly within an application, without using JDBC or SQL. 
mvstore_1027_li=MVStore stands for "multi-version store". 
mvstore_1028_li=Each store contains a number of maps that can be accessed using the <code>java.util.Map</code> interface. 
mvstore_1029_li=Both file-based persistence and in-memory operation are supported. 
mvstore_1030_li=It is intended to be fast, simple to use, and small. 
mvstore_1031_li=Old versions of the data can be read concurrently with all other operations. 
mvstore_1032_li=Transactions are supported (including concurrent transactions and 2-phase commit). 
mvstore_1033_li=The tool is very modular. It supports pluggable data types and serialization, pluggable storage (to a file, to off-heap memory), pluggable map implementations (B-tree, R-tree, concurrent B-tree currently), BLOB storage, and a file system abstraction to support encrypted files and zip files. 
mvstore_1034_h2=Example Code
mvstore_1035_p=\ The following sample code shows how to use the tool\: 
mvstore_1036_h2=Store Builder
mvstore_1037_p=\ The <code>MVStore.Builder</code> provides a fluid interface to build a store if configuration options are needed. Example usage\: 
mvstore_1038_p=\ The list of available options is\: 
mvstore_1039_li=autoCommitBufferSize\: the size of the write buffer. 
mvstore_1040_li=autoCommitDisabled\: to disable auto-commit. 
mvstore_1041_li=backgroundExceptionHandler\: a handler for exceptions that could occur while writing in the background. 
mvstore_1042_li=cacheSize\: the cache size in MB. 
mvstore_1043_li=compress\: compress the data when storing using a fast algorithm (LZF). 
mvstore_1044_li=compressHigh\: compress the data when storing using a slower algorithm (Deflate). 
mvstore_1045_li=encryptionKey\: the key for file encryption. 
mvstore_1046_li=fileName\: the name of the file, for file based stores. 
mvstore_1047_li=fileStore\: the storage implementation to use. 
mvstore_1048_li=pageSplitSize\: the point where pages are split. 
mvstore_1049_li=readOnly\: open the file in read-only mode. 
mvstore_1050_h2=R-Tree
mvstore_1051_p=\ The <code>MVRTreeMap</code> is an R-tree implementation that supports fast spatial queries. It can be used as follows\: 
mvstore_1052_p=\ The default number of dimensions is 2. To use a different number of dimensions, call <code>new MVRTreeMap.Builder&lt;String&gt;().dimensions(3)</code>. The minimum number of dimensions is 1, the maximum is 32. 
mvstore_1053_h2=Features
mvstore_1054_h3=Maps
mvstore_1055_p=\ Each store contains a set of named maps. A map is sorted by key, and supports the common lookup operations, including access to the first and last key, iterate over some or all keys, and so on. 
mvstore_1056_p=\ Also supported, and very uncommon for maps, is fast index lookup\: the entries of the map can be be efficiently accessed like a random-access list (get the entry at the given index), and the index of a key can be calculated efficiently. That also means getting the median of two keys is very fast, and a range of keys can be counted very quickly. The iterator supports fast skipping. This is possible because internally, each map is organized in the form of a counted B+-tree. 
mvstore_1057_p=\ In database terms, a map can be used like a table, where the key of the map is the primary key of the table, and the value is the row. A map can also represent an index, where the key of the map is the key of the index, and the value of the map is the primary key of the table (for non-unique indexes, the key of the map must also contain the primary key). 
mvstore_1058_h3=Versions
mvstore_1059_p=\ A version is a snapshot of all the data of all maps at a given point in time. Creating a snapshot is fast\: only those pages that are changed after a snapshot are copied. This behavior is also called COW (copy on write). Rollback to an old version is supported. Old versions are readable until old data is purged. 
mvstore_1060_p=\ The following sample code show how to create a store, open a map, add some data, and access the current and an old version\: 
mvstore_1061_h3=Transactions
mvstore_1062_p=\ To support multiple concurrent open transactions, a transaction utility is included, the <code>TransactionStore</code>. The tool supports PostgreSQL style "read committed" transaction isolation with savepoints, two-phase commit, and other features typically available in a database. There is no limit on the size of a transaction (the log is written to disk for large or long running transactions). 
mvstore_1063_p=\ Internally, this utility stores the old versions of changed entries in a separate map, similar to a transaction log, except that entries of a closed transaction are removed, and the log is usually not stored for short transactions. For common use cases, the storage overhead of this utility is very small compared to the overhead of a regular transaction log. 
mvstore_1064_h3=In-Memory Performance and Usage
mvstore_1065_p=\ Performance of in-memory operations is comparable with <code>java.util.TreeMap</code>, but usually slower than <code>java.util.HashMap</code>. 
mvstore_1066_p=\ The memory overhead for large maps is slightly better than for the regular map implementations, but there is a higher overhead per map. For maps with less than about 25 entries, the regular map implementations need less memory. 
mvstore_1067_p=\ If no file name is specified, the store operates purely in memory. Except for persisting data, all features are supported in this mode (multi-versioning, index lookup, R-tree and so on). If a file name is specified, all operations occur in memory (with the same performance characteristics) until data is persisted. 
mvstore_1068_p=\ As in all map implementations, keys need to be immutable, that means changing the key object after an entry has been added is not allowed. If a file name is specified, the value may also not be changed after adding an entry, because it might be serialized (which could happen at any time when autocommit is enabled). 
mvstore_1069_h3=Pluggable Data Types
mvstore_1070_p=\ Serialization is pluggable. The default serialization currently supports many common data types, and uses Java serialization for other objects. The following classes are currently directly supported\: <code>Boolean, Byte, Short, Character, Integer, Long, Float, Double, BigInteger, BigDecimal, String, UUID, Date</code> and arrays (both primitive arrays and object arrays). For serialized objects, the size estimate is adjusted using an exponential moving average. 
mvstore_1071_p=\ Parameterized data types are supported (for example one could build a string data type that limits the length). 
mvstore_1072_p=\ The storage engine itself does not have any length limits, so that keys, values, pages, and chunks can be very big (as big as fits in memory). Also, there is no inherent limit to the number of maps and chunks. Due to using a log structured storage, there is no special case handling for large keys or pages. 
mvstore_1073_h3=BLOB Support
mvstore_1074_p=\ There is a mechanism that stores large binary objects by splitting them into smaller blocks. This allows to store objects that don't fit in memory. Streaming as well as random access reads on such objects are supported. This tool is written on top of the store, using only the map interface. 
mvstore_1075_h3=R-Tree and Pluggable Map Implementations
mvstore_1076_p=\ The map implementation is pluggable. In addition to the default <code>MVMap</code> (multi-version map), there is a map that supports concurrent write operations, and a multi-version R-tree map implementation for spatial operations. 
mvstore_1077_h3=Concurrent Operations and Caching
mvstore_1078_p=\ The default map implementation supports concurrent reads on old versions of the data. All such read operations can occur in parallel. Concurrent reads from the page cache, as well as concurrent reads from the file system are supported. Writing changes to the file can occur concurrently to modifying the data, as writing operates on a snapshot. 
mvstore_1079_p=\ Caching is done on the page level. The page cache is a concurrent LIRS cache, which should be resistant against scan operations. 
mvstore_1080_p=\ The default map implementation does not support concurrent modification operations on a map (the same as <code>HashMap</code> and <code>TreeMap</code>). Similar to those classes, the map tries to detect concurrent modifications. 
mvstore_1081_p=\ With the <code>MVMapConcurrent</code> implementation, read operations even on the newest version can happen concurrently with all other operations, without risk of corruption. This comes with slightly reduced speed in single threaded mode, the same as with other <code>ConcurrentHashMap</code> implementations. Write operations first read the relevant pages from disk to memory (this can happen concurrently), and only then modify the data. The in-memory parts of write operations are synchronized. 
mvstore_1082_p=\ For fully scalable concurrent write operations to a map (in-memory and to disk), the map could be split into multiple maps in different stores ('sharding'). The plan is to add such a mechanism later when needed. 
mvstore_1083_h3=Log Structured Storage
mvstore_1084_p=\ Internally, changes are buffered in memory, and once enough changes have accumulated, they are written in one continuous disk write operation. Compared to traditional database storage engines, this should improve write performance for file systems and storage systems that do not efficiently support small random writes, such as Btrfs, as well as SSDs. (According to a test, write throughput of a common SSD increases with write block size, until a block size of 2 MB, and then does not further increase.) By default, changes are automatically written when more than a number of pages are modified, and once every second in a background thread, even if only little data was changed. Changes can also be written explicitly by calling <code>commit()</code>. 
mvstore_1085_p=\ When storing, all changed pages are serialized, optionally compressed using the LZF algorithm, and written sequentially to a free area of the file. Each such change set is called a chunk. All parent pages of the changed B-trees are stored in this chunk as well, so that each chunk also contains the root of each changed map (which is the entry point for reading this version of the data). There is no separate index\: all data is stored as a list of pages. Per store, there is one additional map that contains the metadata (the list of maps, where the root page of each map is stored, and the list of chunks). 
mvstore_1086_p=\ There are usually two write operations per chunk\: one to store the chunk data (the pages), and one to update the file header (so it points to the latest chunk). If the chunk is appended at the end of the file, the file header is only written at the end of the chunk. There is no transaction log, no undo log, and there are no in-place updates (however, unused chunks are overwritten by default). 
mvstore_1087_p=\ Old data is kept for at least 45 seconds (configurable), so that there are no explicit sync operations required to guarantee data consistency. An application can also sync explicitly when needed. To reuse disk space, the chunks with the lowest amount of live data are compacted (the live data is stored again in the next chunk). To improve data locality and disk space usage, the plan is to automatically defragment and compact data. 
mvstore_1088_p=\ Compared to traditional storage engines (that use a transaction log, undo log, and main storage area), the log structured storage is simpler, more flexible, and typically needs less disk operations per change, as data is only written once instead of twice or 3 times, and because the B-tree pages are always full (they are stored next to each other) and can be easily compressed. But temporarily, disk space usage might actually be a bit higher than for a regular database, as disk space is not immediately re-used (there are no in-place updates). 
mvstore_1089_h3=Off-Heap and Pluggable Storage
mvstore_1090_p=\ Storage is pluggable. Unless pure in-memory operation is used, the default storage is to a single file. 
mvstore_1091_p=\ An off-heap storage implementation is available. This storage keeps the data in the off-heap memory, meaning outside of the regular garbage collected heap. This allows to use very large in-memory stores without having to increase the JVM heap, which would increase Java garbage collection pauses a lot. Memory is allocated using <code>ByteBuffer.allocateDirect</code>. One chunk is allocated at a time (each chunk is usually a few MB large), so that allocation cost is low. To use the off-heap storage, call\: 
mvstore_1092_h3=File System Abstraction, File Locking and Online Backup
mvstore_1093_p=\ The file system is pluggable. The same file system abstraction is used as H2 uses. The file can be encrypted using a encrypting file system wrapper. Other file system implementations support reading from a compressed zip or jar file. The file system abstraction closely matches the Java 7 file system API. 
mvstore_1094_p=\ Each store may only be opened once within a JVM. When opening a store, the file is locked in exclusive mode, so that the file can only be changed from within one process. Files can be opened in read-only mode, in which case a shared lock is used. 
mvstore_1095_p=\ The persisted data can be backed up at any time, even during write operations (online backup). To do that, automatic disk space reuse needs to be first disabled, so that new data is always appended at the end of the file. Then, the file can be copied. The file handle is available to the application. It is recommended to use the utility class <code>FileChannelInputStream</code> to do this. For encrypted databases, both the encrypted (raw) file content, as well as the clear text content, can be backed up. 
mvstore_1096_h3=Encrypted Files
mvstore_1097_p=\ File encryption ensures the data can only be read with the correct password. Data can be encrypted as follows\: 
mvstore_1098_p=\ The following algorithms and settings are used\: 
mvstore_1099_li=The password char array is cleared after use, to reduce the risk that the password is stolen even if the attacker has access to the main memory. 
mvstore_1100_li=The password is hashed according to the PBKDF2 standard, using the SHA-256 hash algorithm. 
mvstore_1101_li=The length of the salt is 64 bits, so that an attacker can not use a pre-calculated password hash table (rainbow table). It is generated using a cryptographically secure random number generator. 
mvstore_1102_li=To speed up opening an encrypted stores on Android, the number of PBKDF2 iterations is 10. The higher the value, the better the protection against brute-force password cracking attacks, but the slower is opening a file. 
mvstore_1103_li=The file itself is encrypted using the standardized disk encryption mode XTS-AES. Only little more than one AES-128 round per block is needed. 
mvstore_1104_h3=Tools
mvstore_1105_p=\ There is a tool, the <code>MVStoreTool</code>, to dump the contents of a file. 
mvstore_1106_h3=Exception Handling
mvstore_1107_p=\ This tool does not throw checked exceptions. Instead, unchecked exceptions are thrown if needed. The error message always contains the version of the tool. The following exceptions can occur\: 
mvstore_1108_code=IllegalStateException
mvstore_1109_li=\ if a map was already closed or an IO exception occurred, for example if the file was locked, is already closed, could not be opened or closed, if reading or writing failed, if the file is corrupt, or if there is an internal error in the tool. For such exceptions, an error code is added so that the application can distinguish between different error cases. 
mvstore_1110_code=IllegalArgumentException
mvstore_1111_li=\ if a method was called with an illegal argument. 
mvstore_1112_code=UnsupportedOperationException
mvstore_1113_li=\ if a method was called that is not supported, for example trying to modify a read-only map. 
mvstore_1114_code=ConcurrentModificationException
mvstore_1115_li=\ if a map is modified concurrently. 
mvstore_1116_h3=Storage Engine for H2
mvstore_1117_p=\ For H2 version 1.4 and newer, the MVStore is the default storage engine (supporting SQL, JDBC, transactions, MVCC, and so on). For older versions, append <code>;MV_STORE\=TRUE</code> to the database URL. Even though it can be used with the default table level locking, by default the MVCC mode is enabled when using the MVStore. 
mvstore_1118_h2=File Format
mvstore_1119_p=\ The data is stored in one file. The file contains two file headers (for safety), and a number of chunks. The file headers are one block each; a block is 4096 bytes. Each chunk is at least one block, but typically 200 blocks or more. Data is stored in the chunks in the form of a <a href\="https\://en.wikipedia.org/wiki/Log-structured_file_system">log structured storage</a>. There is one chunk for every version. 
mvstore_1120_p=\ Each chunk contains a number of B-tree pages. As an example, the following code\: 
mvstore_1121_p=\ will result in the following two chunks (excluding metadata)\: 
mvstore_1122_b=Chunk 1\:
mvstore_1123_p=\ - Page 1\: (root) node with 2 entries pointing to page 2 and 3
mvstore_1124_p=\ - Page 2\: leaf with 140 entries (keys 0 - 139)
mvstore_1125_p=\ - Page 3\: leaf with 260 entries (keys 140 - 399)
mvstore_1126_b=Chunk 2\:
mvstore_1127_p=\ - Page 4\: (root) node with 2 entries pointing to page 3 and 5
mvstore_1128_p=\ - Page 5\: leaf with 140 entries (keys 0 - 139)
mvstore_1129_p=\ That means each chunk contains the changes of one version\: the new version of the changed pages and the parent pages, recursively, up to the root page. Pages in subsequent chunks refer to pages in earlier chunks. 
mvstore_1130_h3=File Header
mvstore_1131_p=\ There are two file headers, which normally contain the exact same data. But once in a while, the file headers are updated, and writing could partially fail, which could corrupt a header. That's why there is a second header. Only the file headers are updated in this way (called "in-place update"). The headers contain the following data\: 
mvstore_1132_p=\ The data is stored in the form of a key-value pair. Each value is stored as a hexadecimal number. The entries are\: 
mvstore_1133_li=H\: The entry "H\:2" stands for the the H2 database. 
mvstore_1134_li=block\: The block number where one of the newest chunks starts (but not necessarily the newest). 
mvstore_1135_li=blockSize\: The block size of the file; currently always hex 1000, which is decimal 4096, to match the <a href\="https\://en.wikipedia.org/wiki/Disk_sector">disk sector</a> length of modern hard disks. 
mvstore_1136_li=chunk\: The chunk id, which is normally the same value as the version; however, the chunk id might roll over to 0, while the version doesn't. 
mvstore_1137_li=created\: The number of milliseconds since 1970 when the file was created. 
mvstore_1138_li=format\: The file format number. Currently 1. 
mvstore_1139_li=version\: The version number of the chunk. 
mvstore_1140_li=fletcher\: The <a href\="https\://en.wikipedia.org/wiki/Fletcher's_checksum"> Fletcher-32 checksum</a> of the header. 
mvstore_1141_p=\ When opening the file, both headers are read and the checksum is verified. If both headers are valid, the one with the newer version is used. The chunk with the latest version is then detected (details about this see below), and the rest of the metadata is read from there. If the chunk id, block and version are not stored in the file header, then the latest chunk lookup starts with the last chunk in the file. 
mvstore_1142_h3=Chunk Format
mvstore_1143_p=\ There is one chunk per version. Each chunk consists of a header, the pages that were modified in this version, and a footer. The pages contain the actual data of the maps. The pages inside a chunk are stored right after the header, next to each other (unaligned). The size of a chunk is a multiple of the block size. The footer is stored in the last 128 bytes of the chunk. 
mvstore_1144_p=\ The footer allows to verify that the chunk is completely written (a chunk is written as one write operation), and allows to find the start position of the very last chunk in the file. The chunk header and footer contain the following data\: 
mvstore_1145_p=\ The fields of the chunk header and footer are\: 
mvstore_1146_li=chunk\: The chunk id. 
mvstore_1147_li=block\: The first block of the chunk (multiply by the block size to get the position in the file). 
mvstore_1148_li=len\: The size of the chunk in number of blocks. 
mvstore_1149_li=map\: The id of the newest map; incremented when a new map is created. 
mvstore_1150_li=max\: The sum of all maximum page sizes (see page format). 
mvstore_1151_li=next\: The predicted start block of the next chunk. 
mvstore_1152_li=pages\: The number of pages in the chunk. 
mvstore_1153_li=root\: The position of the metadata root page (see page format). 
mvstore_1154_li=time\: The time the chunk was written, in milliseconds after the file was created. 
mvstore_1155_li=version\: The version this chunk represents. 
mvstore_1156_li=fletcher\: The checksum of the footer. 
mvstore_1157_p=\ Chunks are never updated in-place. Each chunk contains the pages that were changed in that version (there is one chunk per version, see above), plus all the parent nodes of those pages, recursively, up to the root page. If an entry in a map is changed, removed, or added, then the respective page is copied, modified, and stored in the next chunk, and the number of live pages in the old chunk is decremented. This mechanism is called copy-on-write, and is similar to how the <a href\="https\://en.wikipedia.org/wiki/Btrfs">Btrfs</a> file system works. Chunks without live pages are marked as free, so the space can be re-used by more recent chunks. Because not all chunks are of the same size, there can be a number of free blocks in front of a chunk for some time (until a small chunk is written or the chunks are compacted). There is a <a href\="http\://stackoverflow.com/questions/13650134/after-how-many-seconds-are-file-system-write-buffers-typically-flushed"> delay of 45 seconds</a> (by default) before a free chunk is overwritten, to ensure new versions are persisted first. 
mvstore_1158_p=\ How the newest chunk is located when opening a store\: The file header contains the position of a recent chunk, but not always the newest one. This is to reduce the number of file header updates. After opening the file, the file headers, and the chunk footer of the very last chunk (at the end of the file) are read. From those candidates, the header of the most recent chunk is read. If it contains a "next" pointer (see above), those chunk's header and footer are read as well. If it turned out to be a newer valid chunk, this is repeated, until the newest chunk was found. Before writing a chunk, the position of the next chunk is predicted based on the assumption that the next chunk will be of the same size as the current one. When the next chunk is written, and the previous prediction turned out to be incorrect, the file header is updated as well. In any case, the file header is updated if the next chain gets longer than 20 hops. 
mvstore_1159_h3=Page Format
mvstore_1160_p=\ Each map is a <a href\="https\://en.wikipedia.org/wiki/B-tree">B-tree</a>, and the map data is stored in (B-tree-) pages. There are leaf pages that contain the key-value pairs of the map, and internal nodes, which only contain keys and pointers to leaf pages. The root of a tree is either a leaf or an internal node. Unlike file header and chunk header and footer, the page data is not human readable. Instead, it is stored as byte arrays, with long (8 bytes), int (4 bytes), short (2 bytes), and <a href\="https\://en.wikipedia.org/wiki/Variable-length_quantity">variable size int and long</a> (1 to 5 / 10 bytes). The page format is\: 
mvstore_1161_li=length (int)\: Length of the page in bytes. 
mvstore_1162_li=checksum (short)\: Checksum (chunk id xor offset within the chunk xor page length). 
mvstore_1163_li=mapId (variable size int)\: The id of the map this page belongs to. 
mvstore_1164_li=len (variable size int)\: The number of keys in the page. 
mvstore_1165_li=type (byte)\: The page type (0 for leaf page, 1 for internal node; plus 2 if the keys and values are compressed with the LZF algorithm, or plus 6 if the keys and values are compressed with the Deflate algorithm). 
mvstore_1166_li=children (array of long; internal nodes only)\: The position of the children. 
mvstore_1167_li=childCounts (array of variable size long; internal nodes only)\: The total number of entries for the given child page. 
mvstore_1168_li=keys (byte array)\: All keys, stored depending on the data type. 
mvstore_1169_li=values (byte array; leaf pages only)\: All values, stored depending on the data type. 
mvstore_1170_p=\ Even though this is not required by the file format, pages are stored in the following order\: For each map, the root page is stored first, then the internal nodes (if there are any), and then the leaf pages. This should speed up reads for media where sequential reads are faster than random access reads. The metadata map is stored at the end of a chunk. 
mvstore_1171_p=\ Pointers to pages are stored as a long, using a special format\: 26 bits for the chunk id, 32 bits for the offset within the chunk, 5 bits for the length code, 1 bit for the page type (leaf or internal node). The page type is encoded so that when clearing or removing a map, leaf pages don't have to be read (internal nodes do have to be read in order to know where all the pages are; but in a typical B-tree the vast majority of the pages are leaf pages). The absolute file position is not included so that chunks can be moved within the file without having to change page pointers; only the chunk metadata needs to be changed. The length code is a number from 0 to 31, where 0 means the maximum length of the page is 32 bytes, 1 means 48 bytes, 2\: 64, 3\: 96, 4\: 128, 5\: 192, and so on until 31 which means longer than 1 MB. That way, reading a page only requires one read operation (except for very large pages). The sum of the maximum length of all pages is stored in the chunk metadata (field "max"), and when a page is marked as removed, the live maximum length is adjusted. This allows to estimate the amount of free space within a block, in addition to the number of free pages. 
mvstore_1172_p=\ The total number of entries in child pages are kept to allow efficient range counting, lookup by index, and skip operations. The pages form a <a href\="http\://www.chiark.greenend.org.uk/~sgtatham/algorithms/cbtree.html">counted B-tree</a>. 
mvstore_1173_p=\ Data compression\: The data after the page type are optionally compressed using the LZF algorithm. 
mvstore_1174_h3=Metadata Map
mvstore_1175_p=\ In addition to the user maps, there is one metadata map that contains names and positions of user maps, and chunk metadata. The very last page of a chunk contains the root page of that metadata map. The exact position of this root page is stored in the chunk header. This page (directly or indirectly) points to the root pages of all other maps. The metadata map of a store with a map named "data", and one chunk, contains the following entries\: 
mvstore_1176_li=chunk.1\: The metadata of chunk 1. This is the same data as the chunk header, plus the number of live pages, and the maximum live length. 
mvstore_1177_li=map.1\: The metadata of map 1. The entries are\: name, createVersion, and type. 
mvstore_1178_li=name.data\: The map id of the map named "data". The value is "1". 
mvstore_1179_li=root.1\: The root position of map 1. 
mvstore_1180_li=setting.storeVersion\: The store version (a user defined value). 
mvstore_1181_h2=Similar Projects and Differences to Other Storage Engines
mvstore_1182_p=\ Unlike similar storage engines like LevelDB and Kyoto Cabinet, the MVStore is written in Java and can easily be embedded in a Java and Android application. 
mvstore_1183_p=\ The MVStore is somewhat similar to the Berkeley DB Java Edition because it is also written in Java, and is also a log structured storage, but the H2 license is more liberal. 
mvstore_1184_p=\ Like SQLite 3, the MVStore keeps all data in one file. Unlike SQLite 3, the MVStore uses is a log structured storage. The plan is to make the MVStore both easier to use as well as faster than SQLite 3. In a recent (very simple) test, the MVStore was about twice as fast as SQLite 3 on Android. 
mvstore_1185_p=\ The API of the MVStore is similar to MapDB (previously known as JDBM) from Jan Kotek, and some code is shared between MVStore and MapDB. However, unlike MapDB, the MVStore uses is a log structured storage. The MVStore does not have a record size limit. 
mvstore_1186_h2=Current State
mvstore_1187_p=\ The code is still experimental at this stage. The API as well as the behavior may partially change. Features may be added and removed (even though the main features will stay). 
mvstore_1188_h2=Requirements
mvstore_1189_p=\ The MVStore is included in the latest H2 jar file. 
mvstore_1190_p=\ There are no special requirements to use it. The MVStore should run on any JVM as well as on Android. 
mvstore_1191_p=\ To build just the MVStore (without the database engine), run\: 
mvstore_1192_p=\ This will create the file <code>bin/h2mvstore-1.4.178.jar</code> (about 130 KB). 
performance_1000_h1=Performance
performance_1001_a=\ Performance Comparison
performance_1002_a=\ PolePosition Benchmark
performance_1003_a=\ Database Performance Tuning
performance_1004_a=\ Using the Built-In Profiler
performance_1005_a=\ Application Profiling
performance_1006_a=\ Database Profiling
performance_1007_a=\ Statement Execution Plans
performance_1008_a=\ How Data is Stored and How Indexes Work
performance_1009_a=\ Fast Database Import
performance_1010_h2=Performance Comparison
performance_1011_p=\ In many cases H2 is faster than other (open source and not open source) database engines. Please note this is mostly a single connection benchmark run on one computer, with many very simple operations running against the database. This benchmark does not include very complex queries. The embedded mode of H2 is faster than the client-server mode because the per-statement overhead is greatly reduced. 
performance_1012_h3=Embedded
performance_1013_th=Test Case
performance_1014_th=Unit
performance_1015_th=H2
performance_1016_th=HSQLDB
performance_1017_th=Derby
performance_1018_td=Simple\: Init
performance_1019_td=ms
performance_1020_td=1019
performance_1021_td=1907
performance_1022_td=8280
performance_1023_td=Simple\: Query (random)
performance_1024_td=ms
performance_1025_td=1304
performance_1026_td=873
performance_1027_td=1912
performance_1028_td=Simple\: Query (sequential)
performance_1029_td=ms
performance_1030_td=835
performance_1031_td=1839
performance_1032_td=5415
performance_1033_td=Simple\: Update (sequential)
performance_1034_td=ms
performance_1035_td=961
performance_1036_td=2333
performance_1037_td=21759
performance_1038_td=Simple\: Delete (sequential)
performance_1039_td=ms
performance_1040_td=950
performance_1041_td=1922
performance_1042_td=32016
performance_1043_td=Simple\: Memory Usage
performance_1044_td=MB
performance_1045_td=21
performance_1046_td=10
performance_1047_td=8
performance_1048_td=BenchA\: Init
performance_1049_td=ms
performance_1050_td=919
performance_1051_td=2133
performance_1052_td=7528
performance_1053_td=BenchA\: Transactions
performance_1054_td=ms
performance_1055_td=1219
performance_1056_td=2297
performance_1057_td=8541
performance_1058_td=BenchA\: Memory Usage
performance_1059_td=MB
performance_1060_td=12
performance_1061_td=15
performance_1062_td=7
performance_1063_td=BenchB\: Init
performance_1064_td=ms
performance_1065_td=905
performance_1066_td=1993
performance_1067_td=8049
performance_1068_td=BenchB\: Transactions
performance_1069_td=ms
performance_1070_td=1091
performance_1071_td=583
performance_1072_td=1165
performance_1073_td=BenchB\: Memory Usage
performance_1074_td=MB
performance_1075_td=17
performance_1076_td=11
performance_1077_td=8
performance_1078_td=BenchC\: Init
performance_1079_td=ms
performance_1080_td=2491
performance_1081_td=4003
performance_1082_td=8064
performance_1083_td=BenchC\: Transactions
performance_1084_td=ms
performance_1085_td=1979
performance_1086_td=803
performance_1087_td=2840
performance_1088_td=BenchC\: Memory Usage
performance_1089_td=MB
performance_1090_td=19
performance_1091_td=22
performance_1092_td=9
performance_1093_td=Executed statements
performance_1094_td=\#
performance_1095_td=1930995
performance_1096_td=1930995
performance_1097_td=1930995
performance_1098_td=Total time
performance_1099_td=ms
performance_1100_td=13673
performance_1101_td=20686
performance_1102_td=105569
performance_1103_td=Statements per second
performance_1104_td=\#
performance_1105_td=141226
performance_1106_td=93347
performance_1107_td=18291
performance_1108_h3=Client-Server
performance_1109_th=Test Case
performance_1110_th=Unit
performance_1111_th=H2 (Server)
performance_1112_th=HSQLDB
performance_1113_th=Derby
performance_1114_th=PostgreSQL
performance_1115_th=MySQL
performance_1116_td=Simple\: Init
performance_1117_td=ms
performance_1118_td=16338
performance_1119_td=17198
performance_1120_td=27860
performance_1121_td=30156
performance_1122_td=29409
performance_1123_td=Simple\: Query (random)
performance_1124_td=ms
performance_1125_td=3399
performance_1126_td=2582
performance_1127_td=6190
performance_1128_td=3315
performance_1129_td=3342
performance_1130_td=Simple\: Query (sequential)
performance_1131_td=ms
performance_1132_td=21841
performance_1133_td=18699
performance_1134_td=42347
performance_1135_td=30774
performance_1136_td=32611
performance_1137_td=Simple\: Update (sequential)
performance_1138_td=ms
performance_1139_td=6913
performance_1140_td=7745
performance_1141_td=28576
performance_1142_td=32698
performance_1143_td=11350
performance_1144_td=Simple\: Delete (sequential)
performance_1145_td=ms
performance_1146_td=8051
performance_1147_td=9751
performance_1148_td=42202
performance_1149_td=44480
performance_1150_td=16555
performance_1151_td=Simple\: Memory Usage
performance_1152_td=MB
performance_1153_td=22
performance_1154_td=11
performance_1155_td=9
performance_1156_td=0
performance_1157_td=1
performance_1158_td=BenchA\: Init
performance_1159_td=ms
performance_1160_td=12996
performance_1161_td=14720
performance_1162_td=24722
performance_1163_td=26375
performance_1164_td=26060
performance_1165_td=BenchA\: Transactions
performance_1166_td=ms
performance_1167_td=10134
performance_1168_td=10250
performance_1169_td=18452
performance_1170_td=21453
performance_1171_td=15877
performance_1172_td=BenchA\: Memory Usage
performance_1173_td=MB
performance_1174_td=13
performance_1175_td=15
performance_1176_td=9
performance_1177_td=0
performance_1178_td=1
performance_1179_td=BenchB\: Init
performance_1180_td=ms
performance_1181_td=15264
performance_1182_td=16889
performance_1183_td=28546
performance_1184_td=31610
performance_1185_td=29747
performance_1186_td=BenchB\: Transactions
performance_1187_td=ms
performance_1188_td=3017
performance_1189_td=3376
performance_1190_td=1842
performance_1191_td=2771
performance_1192_td=1433
performance_1193_td=BenchB\: Memory Usage
performance_1194_td=MB
performance_1195_td=17
performance_1196_td=12
performance_1197_td=11
performance_1198_td=1
performance_1199_td=1
performance_1200_td=BenchC\: Init
performance_1201_td=ms
performance_1202_td=14020
performance_1203_td=10407
performance_1204_td=17655
performance_1205_td=19520
performance_1206_td=17532
performance_1207_td=BenchC\: Transactions
performance_1208_td=ms
performance_1209_td=5076
performance_1210_td=3160
performance_1211_td=6411
performance_1212_td=6063
performance_1213_td=4530
performance_1214_td=BenchC\: Memory Usage
performance_1215_td=MB
performance_1216_td=19
performance_1217_td=21
performance_1218_td=11
performance_1219_td=1
performance_1220_td=1
performance_1221_td=Executed statements
performance_1222_td=\#
performance_1223_td=1930995
performance_1224_td=1930995
performance_1225_td=1930995
performance_1226_td=1930995
performance_1227_td=1930995
performance_1228_td=Total time
performance_1229_td=ms
performance_1230_td=117049
performance_1231_td=114777
performance_1232_td=244803
performance_1233_td=249215
performance_1234_td=188446
performance_1235_td=Statements per second
performance_1236_td=\#
performance_1237_td=16497
performance_1238_td=16823
performance_1239_td=7887
performance_1240_td=7748
performance_1241_td=10246
performance_1242_h3=Benchmark Results and Comments
performance_1243_h4=H2
performance_1244_p=\ Version 1.4.177 (2014-04-12) was used for the test. For most operations, the performance of H2 is about the same as for HSQLDB. One situation where H2 is slow is large result sets, because they are buffered to disk if more than a certain number of records are returned. The advantage of buffering is\: there is no limit on the result set size. 
performance_1245_h4=HSQLDB
performance_1246_p=\ Version 2.3.2 was used for the test. Cached tables are used in this test (<code>hsqldb.default_table_type\=cached</code>), and the write delay is 1 second (<code>SET WRITE_DELAY 1</code>). 
performance_1247_h4=Derby
performance_1248_p=\ Version 10.10.1.1 was used for the test. Derby is clearly the slowest embedded database in this test. This seems to be a structural problem, because all operations are really slow. It will be hard for the developers of Derby to improve the performance to a reasonable level. A few problems have been identified\: leaving autocommit on is a problem for Derby. If it is switched off during the whole test, the results are about 20% better for Derby. Derby calls <code>FileChannel.force(false)</code>, but only twice per log file (not on each commit). Disabling this call improves performance for Derby by about 2%. Unlike H2, Derby does not call <code>FileDescriptor.sync()</code> on each checkpoint. Derby supports a testing mode (system property <code>derby.system.durability\=test</code>) where durability is disabled. According to the documentation, this setting should be used for testing only, as the database may not recover after a crash. Enabling this setting improves performance by a factor of 2.6 (embedded mode) or 1.4 (server mode). Even if enabled, Derby is still less than half as fast as H2 in default mode. 
performance_1249_h4=PostgreSQL
performance_1250_p=\ Version 9.1.5 was used for the test. The following options where changed in <code>postgresql.conf\: fsync \= off, commit_delay \= 1000</code>. PostgreSQL is run in server mode. The memory usage number is incorrect, because only the memory usage of the JDBC driver is measured. 
performance_1251_h4=MySQL
performance_1252_p=\ Version 5.1.65-log was used for the test. MySQL was run with the InnoDB backend. The setting <code>innodb_flush_log_at_trx_commit</code> (found in the <code>my.ini / my.cnf</code> file) was set to 0. Otherwise (and by default), MySQL is slow (around 140 statements per second in this test) because it tries to flush the data to disk for each commit. For small transactions (when autocommit is on) this is really slow. But many use cases use small or relatively small transactions. Too bad this setting is not listed in the configuration wizard, and it always overwritten when using the wizard. You need to change this setting manually in the file <code>my.ini / my.cnf</code>, and then restart the service. The memory usage number is incorrect, because only the memory usage of the JDBC driver is measured. 
performance_1253_h4=Firebird
performance_1254_p=\ Firebird 1.5 (default installation) was tested, but the results are not published currently. It is possible to run the performance test with the Firebird database, and any information on how to configure Firebird for higher performance are welcome. 
performance_1255_h4=Why Oracle / MS SQL Server / DB2 are Not Listed
performance_1256_p=\ The license of these databases does not allow to publish benchmark results. This doesn't mean that they are fast. They are in fact quite slow, and need a lot of memory. But you will need to test this yourself. SQLite was not tested because the JDBC driver doesn't support transactions. 
performance_1257_h3=About this Benchmark
performance_1258_h4=How to Run
performance_1259_p=\ This test was as follows\: 
performance_1260_h4=Separate Process per Database
performance_1261_p=\ For each database, a new process is started, to ensure the previous test does not impact the current test. 
performance_1262_h4=Number of Connections
performance_1263_p=\ This is mostly a single-connection benchmark. BenchB uses multiple connections; the other tests use one connection. 
performance_1264_h4=Real-World Tests
performance_1265_p=\ Good benchmarks emulate real-world use cases. This benchmark includes 4 test cases\: BenchSimple uses one table and many small updates / deletes. BenchA is similar to the TPC-A test, but single connection / single threaded (see also\: www.tpc.org). BenchB is similar to the TPC-B test, using multiple connections (one thread per connection). BenchC is similar to the TPC-C test, but single connection / single threaded. 
performance_1266_h4=Comparing Embedded with Server Databases
performance_1267_p=\ This is mainly a benchmark for embedded databases (where the application runs in the same virtual machine as the database engine). However MySQL and PostgreSQL are not Java databases and cannot be embedded into a Java application. For the Java databases, both embedded and server modes are tested. 
performance_1268_h4=Test Platform
performance_1269_p=\ This test is run on Mac OS X 10.6. No virus scanner was used, and disk indexing was disabled. The JVM used is Sun JDK 1.6. 
performance_1270_h4=Multiple Runs
performance_1271_p=\ When a Java benchmark is run first, the code is not fully compiled and therefore runs slower than when running multiple times. A benchmark should always run the same test multiple times and ignore the first run(s). This benchmark runs three times, but only the last run is measured. 
performance_1272_h4=Memory Usage
performance_1273_p=\ It is not enough to measure the time taken, the memory usage is important as well. Performance can be improved by using a bigger cache, but the amount of memory is limited. HSQLDB tables are kept fully in memory by default; this benchmark uses 'disk based' tables for all databases. Unfortunately, it is not so easy to calculate the memory usage of PostgreSQL and MySQL, because they run in a different process than the test. This benchmark currently does not print memory usage of those databases. 
performance_1274_h4=Delayed Operations
performance_1275_p=\ Some databases delay some operations (for example flushing the buffers) until after the benchmark is run. This benchmark waits between each database tested, and each database runs in a different process (sequentially). 
performance_1276_h4=Transaction Commit / Durability
performance_1277_p=\ Durability means transaction committed to the database will not be lost. Some databases (for example MySQL) try to enforce this by default by calling <code>fsync()</code> to flush the buffers, but most hard drives don't actually flush all data. Calling the method slows down transaction commit a lot, but doesn't always make data durable. When comparing the results, it is important to think about the effect. Many database suggest to 'batch' operations when possible. This benchmark switches off autocommit when loading the data, and calls commit after each 1000 inserts. However many applications need 'short' transactions at runtime (a commit after each update). This benchmark commits after each update / delete in the simple benchmark, and after each business transaction in the other benchmarks. For databases that support delayed commits, a delay of one second is used. 
performance_1278_h4=Using Prepared Statements
performance_1279_p=\ Wherever possible, the test cases use prepared statements. 
performance_1280_h4=Currently Not Tested\: Startup Time
performance_1281_p=\ The startup time of a database engine is important as well for embedded use. This time is not measured currently. Also, not tested is the time used to create a database and open an existing database. Here, one (wrapper) connection is opened at the start, and for each step a new connection is opened and then closed. 
performance_1282_h2=PolePosition Benchmark
performance_1283_p=\ The PolePosition is an open source benchmark. The algorithms are all quite simple. It was developed / sponsored by db4o. This test was not run for a longer time, so please be aware that the results below are for older database versions (H2 version 1.1, HSQLDB 1.8, Java 1.4). 
performance_1284_th=Test Case
performance_1285_th=Unit
performance_1286_th=H2
performance_1287_th=HSQLDB
performance_1288_th=MySQL
performance_1289_td=Melbourne write
performance_1290_td=ms
performance_1291_td=369
performance_1292_td=249
performance_1293_td=2022
performance_1294_td=Melbourne read
performance_1295_td=ms
performance_1296_td=47
performance_1297_td=49
performance_1298_td=93
performance_1299_td=Melbourne read_hot
performance_1300_td=ms
performance_1301_td=24
performance_1302_td=43
performance_1303_td=95
performance_1304_td=Melbourne delete
performance_1305_td=ms
performance_1306_td=147
performance_1307_td=133
performance_1308_td=176
performance_1309_td=Sepang write
performance_1310_td=ms
performance_1311_td=965
performance_1312_td=1201
performance_1313_td=3213
performance_1314_td=Sepang read
performance_1315_td=ms
performance_1316_td=765
performance_1317_td=948
performance_1318_td=3455
performance_1319_td=Sepang read_hot
performance_1320_td=ms
performance_1321_td=789
performance_1322_td=859
performance_1323_td=3563
performance_1324_td=Sepang delete
performance_1325_td=ms
performance_1326_td=1384
performance_1327_td=1596
performance_1328_td=6214
performance_1329_td=Bahrain write
performance_1330_td=ms
performance_1331_td=1186
performance_1332_td=1387
performance_1333_td=6904
performance_1334_td=Bahrain query_indexed_string
performance_1335_td=ms
performance_1336_td=336
performance_1337_td=170
performance_1338_td=693
performance_1339_td=Bahrain query_string
performance_1340_td=ms
performance_1341_td=18064
performance_1342_td=39703
performance_1343_td=41243
performance_1344_td=Bahrain query_indexed_int
performance_1345_td=ms
performance_1346_td=104
performance_1347_td=134
performance_1348_td=678
performance_1349_td=Bahrain update
performance_1350_td=ms
performance_1351_td=191
performance_1352_td=87
performance_1353_td=159
performance_1354_td=Bahrain delete
performance_1355_td=ms
performance_1356_td=1215
performance_1357_td=729
performance_1358_td=6812
performance_1359_td=Imola retrieve
performance_1360_td=ms
performance_1361_td=198
performance_1362_td=194
performance_1363_td=4036
performance_1364_td=Barcelona write
performance_1365_td=ms
performance_1366_td=413
performance_1367_td=832
performance_1368_td=3191
performance_1369_td=Barcelona read
performance_1370_td=ms
performance_1371_td=119
performance_1372_td=160
performance_1373_td=1177
performance_1374_td=Barcelona query
performance_1375_td=ms
performance_1376_td=20
performance_1377_td=5169
performance_1378_td=101
performance_1379_td=Barcelona delete
performance_1380_td=ms
performance_1381_td=388
performance_1382_td=319
performance_1383_td=3287
performance_1384_td=Total
performance_1385_td=ms
performance_1386_td=26724
performance_1387_td=53962
performance_1388_td=87112
performance_1389_p=\ There are a few problems with the PolePosition test\: 
performance_1390_li=\ HSQLDB uses in-memory tables by default while H2 uses persistent tables. The HSQLDB version included in PolePosition does not support changing this, so you need to replace <code>poleposition-0.20/lib/hsqldb.jar</code> with a newer version (for example <code>hsqldb-1.8.0.7.jar</code>), and then use the setting <code>hsqldb.connecturl\=jdbc\:hsqldb\:file\:data/hsqldb/dbbench2;hsqldb.default_table_type\=cached;sql.enforce_size\=true</code> in the file <code>Jdbc.properties</code>. 
performance_1391_li=HSQLDB keeps the database open between tests, while H2 closes the database (losing all the cache). To change that, use the database URL <code>jdbc\:h2\:file\:data/h2/dbbench;DB_CLOSE_DELAY\=-1</code> 
performance_1392_li=The amount of cache memory is quite important, specially for the PolePosition test. Unfortunately, the PolePosition test does not take this into account. 
performance_1393_h2=Database Performance Tuning
performance_1394_h3=Keep Connections Open or Use a Connection Pool
performance_1395_p=\ If your application opens and closes connections a lot (for example, for each request), you should consider using a <a href\="tutorial.html\#connection_pool">connection pool</a>. Opening a connection using <code>DriverManager.getConnection</code> is specially slow if the database is closed. By default the database is closed if the last connection is closed. 
performance_1396_p=\ If you open and close connections a lot but don't want to use a connection pool, consider keeping a 'sentinel' connection open for as long as the application runs, or use delayed database closing. See also <a href\="features.html\#closing_a_database">Closing a database</a>. 
performance_1397_h3=Use a Modern JVM
performance_1398_p=\ Newer JVMs are faster. Upgrading to the latest version of your JVM can provide a "free" boost to performance. Switching from the default Client JVM to the Server JVM using the <code>-server</code> command-line option improves performance at the cost of a slight increase in start-up time. 
performance_1399_h3=Virus Scanners
performance_1400_p=\ Some virus scanners scan files every time they are accessed. It is very important for performance that database files are not scanned for viruses. The database engine never interprets the data stored in the files as programs, that means even if somebody would store a virus in a database file, this would be harmless (when the virus does not run, it cannot spread). Some virus scanners allow to exclude files by suffix. Ensure files ending with <code>.db</code> are not scanned. 
performance_1401_h3=Using the Trace Options
performance_1402_p=\ If the performance hot spots are in the database engine, in many cases the performance can be optimized by creating additional indexes, or changing the schema. Sometimes the application does not directly generate the SQL statements, for example if an O/R mapping tool is used. To view the SQL statements and JDBC API calls, you can use the trace options. For more information, see <a href\="features.html\#trace_options">Using the Trace Options</a>. 
performance_1403_h3=Index Usage
performance_1404_p=\ This database uses indexes to improve the performance of <code>SELECT, UPDATE, DELETE</code>. If a column is used in the <code>WHERE</code> clause of a query, and if an index exists on this column, then the index can be used. Multi-column indexes are used if all or the first columns of the index are used. Both equality lookup and range scans are supported. Indexes are used to order result sets, but only if the condition uses the same index or no index at all. The results are sorted in memory if required. Indexes are created automatically for primary key and unique constraints. Indexes are also created for foreign key constraints, if required. For other columns, indexes need to be created manually using the <code>CREATE INDEX</code> statement. 
performance_1405_h3=How Data is Stored Internally
performance_1406_p=\ For persistent databases, if a table is created with a single column primary key of type <code>BIGINT, INT, SMALLINT, TINYINT</code>, then the data of the table is organized in this way. This is sometimes also called a "clustered index" or "index organized table". 
performance_1407_p=\ H2 internally stores table data and indexes in the form of b-trees. Each b-tree stores entries as a list of unique keys (one or more columns) and data (zero or more columns). The table data is always organized in the form of a "data b-tree" with a single column key of type <code>long</code>. If a single column primary key of type <code>BIGINT, INT, SMALLINT, TINYINT</code> is specified when creating the table (or just after creating the table, but before inserting any rows), then this column is used as the key of the data b-tree. If no primary key has been specified, if the primary key column is of another data type, or if the primary key contains more than one column, then a hidden auto-increment column of type <code>BIGINT</code> is added to the table, which is used as the key for the data b-tree. All other columns of the table are stored within the data area of this data b-tree (except for large <code>BLOB, CLOB</code> columns, which are stored externally). 
performance_1408_p=\ For each additional index, one new "index b-tree" is created. The key of this b-tree consists of the indexed columns, plus the key of the data b-tree. If a primary key is created after the table has been created, or if the primary key contains multiple column, or if the primary key is not of the data types listed above, then the primary key is stored in a new index b-tree. 
performance_1409_h3=Optimizer
performance_1410_p=\ This database uses a cost based optimizer. For simple and queries and queries with medium complexity (less than 7 tables in the join), the expected cost (running time) of all possible plans is calculated, and the plan with the lowest cost is used. For more complex queries, the algorithm first tries all possible combinations for the first few tables, and the remaining tables added using a greedy algorithm (this works well for most joins). Afterwards a genetic algorithm is used to test at most 2000 distinct plans. Only left-deep plans are evaluated. 
performance_1411_h3=Expression Optimization
performance_1412_p=\ After the statement is parsed, all expressions are simplified automatically if possible. Operations are evaluated only once if all parameters are constant. Functions are also optimized, but only if the function is constant (always returns the same result for the same parameter values). If the <code>WHERE</code> clause is always false, then the table is not accessed at all. 
performance_1413_h3=COUNT(*) Optimization
performance_1414_p=\ If the query only counts all rows of a table, then the data is not accessed. However, this is only possible if no <code>WHERE</code> clause is used, that means it only works for queries of the form <code>SELECT COUNT(*) FROM table</code>. 
performance_1415_h3=Updating Optimizer Statistics / Column Selectivity
performance_1416_p=\ When executing a query, at most one index per join can be used. If the same table is joined multiple times, for each join only one index is used (the same index could be used for both joins, or each join could use a different index). Example\: for the query <code>SELECT * FROM TEST T1, TEST T2 WHERE T1.NAME\='A' AND T2.ID\=T1.ID</code>, two index can be used, in this case the index on NAME for T1 and the index on ID for T2. 
performance_1417_p=\ If a table has multiple indexes, sometimes more than one index could be used. Example\: if there is a table <code>TEST(ID, NAME, FIRSTNAME)</code> and an index on each column, then two indexes could be used for the query <code>SELECT * FROM TEST WHERE NAME\='A' AND FIRSTNAME\='B'</code>, the index on NAME or the index on FIRSTNAME. It is not possible to use both indexes at the same time. Which index is used depends on the selectivity of the column. The selectivity describes the 'uniqueness' of values in a column. A selectivity of 100 means each value appears only once, and a selectivity of 1 means the same value appears in many or most rows. For the query above, the index on NAME should be used if the table contains more distinct names than first names. 
performance_1418_p=\ The SQL statement <code>ANALYZE</code> can be used to automatically estimate the selectivity of the columns in the tables. This command should be run from time to time to improve the query plans generated by the optimizer. 
performance_1419_h3=In-Memory (Hash) Indexes
performance_1420_p=\ Using in-memory indexes, specially in-memory hash indexes, can speed up queries and data manipulation. 
performance_1421_p=In-memory indexes are automatically used for in-memory databases, but can also be created for persistent databases using <code>CREATE MEMORY TABLE</code>. In many cases, the rows itself will also be kept in-memory. Please note this may cause memory problems for large tables. 
performance_1422_p=\ In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID \= ?</code>) but not range scan (<code>WHERE ID &lt; ?</code>). To use hash indexes, use HASH as in\: <code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>. 
performance_1423_h3=Use Prepared Statements
performance_1424_p=\ If possible, use prepared statements with parameters. 
performance_1425_h3=Prepared Statements and IN(...)
performance_1426_p=\ Avoid generating SQL statements with a variable size IN(...) list. Instead, use a prepared statement with arrays as in the following example\: 
performance_1427_h3=Optimization Examples
performance_1428_p=\ See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database. 
performance_1429_h3=Cache Size and Type
performance_1430_p=\ By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href\="features.html\#cache_settings">Cache Settings</a>. 
performance_1431_h3=Data Types
performance_1432_p=\ Each data type has different storage and performance characteristics\: 
performance_1433_li=The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types. 
performance_1434_li=Text types are slower to read, write, and compare than numeric types and generally require more storage. 
performance_1435_li=See <a href\="advanced.html\#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance. 
performance_1436_li=Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types. 
performance_1437_code=SMALLINT/TINYINT/BOOLEAN
performance_1438_li=\ are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes. 
performance_1439_h3=Sorted Insert Optimization
performance_1440_p=\ To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement\: 
performance_1441_h2=Using the Built-In Profiler
performance_1442_p=\ A very simple Java profiler is built-in. To use it, use the following template\: 
performance_1443_h2=Application Profiling
performance_1444_h3=Analyze First
performance_1445_p=\ Before trying to optimize performance, it is important to understand where the problem is (what part of the application is slow). Blind optimization or optimization based on guesses should be avoided, because usually it is not an efficient strategy. There are various ways to analyze an application. Sometimes two implementations can be compared using <code>System.currentTimeMillis()</code>. But this does not work for complex applications with many modules, and for memory problems. 
performance_1446_p=\ A simple way to profile an application is to use the built-in profiling tool of java. Example\: 
performance_1447_p=\ Unfortunately, it is only possible to profile the application from start to end. Another solution is to create a number of full thread dumps. To do that, first run <code>jps -l</code> to get the process id, and then run <code>jstack &lt;pid&gt;</code> or <code>kill -QUIT &lt;pid&gt;</code> (Linux) or press Ctrl+C (Windows). 
performance_1448_p=\ A simple profiling tool is included in H2. To use it, the application needs to be changed slightly. Example\: 
performance_1449_p=\ The profiler is built into the H2 Console tool, to analyze databases that open slowly. To use it, run the H2 Console, and then click on 'Test Connection'. Afterwards, click on "Test successful" and you get the most common stack traces, which helps to find out why it took so long to connect. You will only get the stack traces if opening the database took more than a few seconds. 
performance_1450_h2=Database Profiling
performance_1451_p=\ The <code>ConvertTraceFile</code> tool generates SQL statement statistics at the end of the SQL script file. The format used is similar to the profiling data generated when using <code>java -Xrunhprof</code>. For this to work, the trace level needs to be 2 or higher (<code>TRACE_LEVEL_FILE\=2</code>). The easiest way to set the trace level is to append the setting to the database URL, for example\: <code>jdbc\:h2\:~/test;TRACE_LEVEL_FILE\=2</code> or <code>jdbc\:h2\:tcp\://localhost/~/test;TRACE_LEVEL_FILE\=2</code>. As an example, execute the the following script using the H2 Console\: 
performance_1452_p=\ After running the test case, convert the <code>.trace.db</code> file using the <code>ConvertTraceFile</code> tool. The trace file is located in the same directory as the database file. 
performance_1453_p=\ The generated file <code>test.sql</code> will contain the SQL statements as well as the following profiling data (results vary)\: 
performance_1454_h2=Statement Execution Plans
performance_1455_p=\ The SQL statement <code>EXPLAIN</code> displays the indexes and optimizations the database uses for a statement. The following statements support <code>EXPLAIN</code>\: <code>SELECT, UPDATE, DELETE, MERGE, INSERT</code>. The following query shows that the database uses the primary key index to search for rows\: 
performance_1456_p=\ For joins, the tables in the execution plan are sorted in the order they are processed. The following query shows the database first processes the table <code>INVOICE</code> (using the primary key). For each row, it will additionally check that the value of the column <code>AMOUNT</code> is larger than zero, and for those rows the database will search in the table <code>CUSTOMER</code> (using the primary key). The query plan contains some redundancy so it is a valid statement. 
performance_1457_h3=Displaying the Scan Count
performance_1458_code=EXPLAIN ANALYZE
performance_1459_p=\ additionally shows the scanned rows per table and pages read from disk per table or index. This will actually execute the query, unlike <code>EXPLAIN</code> which only prepares it. The following query scanned 1000 rows, and to do that had to read 85 pages from the data area of the table. Running the query twice will not list the pages read from disk, because they are now in the cache. The <code>tableScan</code> means this query doesn't use an index. 
performance_1460_p=\ The cache will prevent the pages are read twice. H2 reads all columns of the row unless only the columns in the index are read. Except for large CLOB and BLOB, which are not store in the table. 
performance_1461_h3=Special Optimizations
performance_1462_p=\ For certain queries, the database doesn't need to read all rows, or doesn't need to sort the result even if <code>ORDER BY</code> is used. 
performance_1463_p=\ For queries of the form <code>SELECT COUNT(*), MIN(ID), MAX(ID) FROM TEST</code>, the query plan includes the line <code>/* direct lookup */</code> if the data can be read from an index. 
performance_1464_p=\ For queries of the form <code>SELECT DISTINCT CUSTOMER_ID FROM INVOICE</code>, the query plan includes the line <code>/* distinct */</code> if there is an non-unique or multi-column index on this column, and if this column has a low selectivity. 
performance_1465_p=\ For queries of the form <code>SELECT * FROM TEST ORDER BY ID</code>, the query plan includes the line <code>/* index sorted */</code> to indicate there is no separate sorting required. 
performance_1466_p=\ For queries of the form <code>SELECT * FROM TEST GROUP BY ID ORDER BY ID</code>, the query plan includes the line <code>/* group sorted */</code> to indicate there is no separate sorting required. 
performance_1467_h2=How Data is Stored and How Indexes Work
performance_1468_p=\ Internally, each row in a table is identified by a unique number, the row id. The rows of a table are stored with the row id as the key. The row id is a number of type long. If a table has a single column primary key of type <code>INT</code> or <code>BIGINT</code>, then the value of this column is the row id, otherwise the database generates the row id automatically. There is a (non-standard) way to access the row id\: using the <code>_ROWID_</code> pseudo-column\: 
performance_1469_p=\ The data is stored in the database as follows\: 
performance_1470_th=_ROWID_
performance_1471_th=FIRST_NAME
performance_1472_th=NAME
performance_1473_th=CITY
performance_1474_th=PHONE
performance_1475_td=1
performance_1476_td=John
performance_1477_td=Miller
performance_1478_td=Berne
performance_1479_td=123 456 789
performance_1480_td=2
performance_1481_td=Philip
performance_1482_td=Jones
performance_1483_td=Berne
performance_1484_td=123 012 345
performance_1485_p=\ Access by row id is fast because the data is sorted by this key. Please note the row id is not available until after the row was added (that means, it can not be used in computed columns or constraints). If the query condition does not contain the row id (and if no other index can be used), then all rows of the table are scanned. A table scan iterates over all rows in the table, in the order of the row id. To find out what strategy the database uses to retrieve the data, use <code>EXPLAIN SELECT</code>\: 
performance_1486_h3=Indexes
performance_1487_p=\ An index internally is basically just a table that contains the indexed column(s), plus the row id\: 
performance_1488_p=\ In the index, the data is sorted by the indexed columns. So this index contains the following data\: 
performance_1489_th=CITY
performance_1490_th=NAME
performance_1491_th=FIRST_NAME
performance_1492_th=_ROWID_
performance_1493_td=Berne
performance_1494_td=Jones
performance_1495_td=Philip
performance_1496_td=2
performance_1497_td=Berne
performance_1498_td=Miller
performance_1499_td=John
performance_1500_td=1
performance_1501_p=\ When the database uses an index to query the data, it searches the index for the given data, and (if required) reads the remaining columns in the main data table (retrieved using the row id). An index on city, name, and first name (multi-column index) allows to quickly search for rows when the city, name, and first name are known. If only the city and name, or only the city is known, then this index is also used (so creating an additional index on just the city is not needed). This index is also used when reading all rows, sorted by the indexed columns. However, if only the first name is known, then this index is not used\: 
performance_1502_p=\ If your application often queries the table for a phone number, then it makes sense to create an additional index on it\: 
performance_1503_p=\ This index contains the phone number, and the row id\: 
performance_1504_th=PHONE
performance_1505_th=_ROWID_
performance_1506_td=123 012 345
performance_1507_td=2
performance_1508_td=123 456 789
performance_1509_td=1
performance_1510_h3=Using Multiple Indexes
performance_1511_p=\ Within a query, only one index per logical table is used. Using the condition <code>PHONE \= '123 567 789' OR CITY \= 'Berne'</code> would use a table scan instead of first using the index on the phone number and then the index on the city. It makes sense to write two queries and combine then using <code>UNION</code>. In this case, each individual query uses a different index\: 
performance_1512_h2=Fast Database Import
performance_1513_p=\ To speed up large imports, consider using the following options temporarily\: 
performance_1514_code=SET LOG 0
performance_1515_li=\ (disabling the transaction log) 
performance_1516_code=SET CACHE_SIZE
performance_1517_li=\ (a large cache is faster) 
performance_1518_code=SET LOCK_MODE 0
performance_1519_li=\ (disable locking) 
performance_1520_code=SET UNDO_LOG 0
performance_1521_li=\ (disable the session undo log) 
performance_1522_p=\ These options can be set in the database URL\: <code>jdbc\:h2\:~/test;LOG\=0;CACHE_SIZE\=65536;LOCK_MODE\=0;UNDO_LOG\=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use. 
performance_1523_p=\ If you have to import a lot of rows, use a PreparedStatement or use CSV import. Please note that <code>CREATE TABLE(...) ... AS SELECT ...</code> is faster than <code>CREATE TABLE(...); INSERT INTO ... SELECT ...</code>. 
quickstart_1000_h1=Quickstart
quickstart_1001_a=\ Embedding H2 in an Application
quickstart_1002_a=\ The H2 Console Application
quickstart_1003_h2=Embedding H2 in an Application
quickstart_1004_p=\ This database can be used in embedded mode, or in server mode. To use it in embedded mode, you need to\: 
quickstart_1005_li=Add the <code>h2*.jar</code> to the classpath (H2 does not have any dependencies) 
quickstart_1006_li=Use the JDBC driver class\: <code>org.h2.Driver</code> 
quickstart_1007_li=The database URL <code>jdbc\:h2\:~/test</code> opens the database <code>test</code> in your user home directory 
quickstart_1008_li=A new database is automatically created 
quickstart_1009_h2=The H2 Console Application
quickstart_1010_p=\ The Console lets you access a SQL database using a browser interface. 
quickstart_1011_p=\ If you don't have Windows XP, or if something does not work as expected, please see the detailed description in the <a href\="tutorial.html">Tutorial</a>. 
quickstart_1012_h3=Step-by-Step
quickstart_1013_h4=Installation
quickstart_1014_p=\ Install the software using the Windows Installer (if you did not yet do that). 
quickstart_1015_h4=Start the Console
quickstart_1016_p=\ Click [Start], [All Programs], [H2], and [H2 Console (Command Line)]\:
quickstart_1017_p=\ A new console window appears\:
quickstart_1018_p=\ Also, a new browser page should open with the URL <a href\="http\://localhost\:8082" class\="notranslate">http\://localhost\:8082</a>. You may get a security warning from the firewall. If you don't want other computers in the network to access the database on your machine, you can let the firewall block these connections. Only local connections are required at this time. 
quickstart_1019_h4=Login
quickstart_1020_p=\ Select [Generic H2] and click [Connect]\:
quickstart_1021_p=\ You are now logged in. 
quickstart_1022_h4=Sample
quickstart_1023_p=\ Click on the [Sample SQL Script]\:
quickstart_1024_p=\ The SQL commands appear in the command area.
quickstart_1025_h4=Execute
quickstart_1026_p=\ Click [Run]
quickstart_1027_p=\ On the left side, a new entry TEST is added below the database icon. The operations and results of the statements are shown below the script.
quickstart_1028_h4=Disconnect
quickstart_1029_p=\ Click on [Disconnect]\:
quickstart_1030_p=\ to close the connection. 
quickstart_1031_h4=End
quickstart_1032_p=\ Close the console window. For more information, see the <a href\="tutorial.html">Tutorial</a>. 
roadmap_1000_h1=Roadmap
roadmap_1001_p=\ New (feature) requests will usually be added at the very end of the list. The priority is increased for important and popular requests. Of course, patches are always welcome, but are not always applied as is. See also <a href\="build.html\#providing_patches">Providing Patches</a>. 
roadmap_1002_h2=Version 1.5.x\: Planned Changes
roadmap_1003_li=Replace file password hash with file encryption key; validate encryption key when connecting. 
roadmap_1004_li=Remove "set binary collation" feature. 
roadmap_1005_li=Remove the encryption algorithm XTEA. 
roadmap_1006_h2=Version 1.4.x\: Planned Changes
roadmap_1007_li=Change license to MPL 2.0. 
roadmap_1008_li=Automatic migration from 1.3 databases to 1.4. 
roadmap_1009_li=Option to disable the file name suffix somehow (issue 447). 
roadmap_1010_h2=Priority 1
roadmap_1011_li=Bugfixes. 
roadmap_1012_li=More tests with MULTI_THREADED\=1 (and MULTI_THREADED with MVCC)\: Online backup (using the 'backup' statement). 
roadmap_1013_li=Server side cursors. 
roadmap_1014_h2=Priority 2
roadmap_1015_li=Support hints for the optimizer (which index to use, enforce the join order). 
roadmap_1016_li=Full outer joins. 
roadmap_1017_li=Access rights\: remember the owner of an object. Create, alter and drop privileges. COMMENT\: allow owner of object to change it. Issue 208\: Access rights for schemas. 
roadmap_1018_li=Test multi-threaded in-memory db access. 
roadmap_1019_li=MySQL, MS SQL Server compatibility\: support case sensitive (mixed case) identifiers without quotes. 
roadmap_1020_li=Support GRANT SELECT, UPDATE ON [schemaName.] *. 
roadmap_1021_li=Migrate database tool (also from other database engines). For Oracle, maybe use DBMS_METADATA.GET_DDL / GET_DEPENDENT_DDL. 
roadmap_1022_li=Clustering\: support mixed clustering mode (one embedded, others in server mode). 
roadmap_1023_li=Clustering\: reads should be randomly distributed (optional) or to a designated database on RAM (parameter\: READ_FROM\=3). 
roadmap_1024_li=Window functions\: RANK() and DENSE_RANK(), partition using OVER(). select *, count(*) over() as fullCount from ... limit 4; 
roadmap_1025_li=PostgreSQL catalog\: use BEFORE SELECT triggers instead of views over metadata tables. 
roadmap_1026_li=Compatibility\: automatically load functions from a script depending on the mode - see FunctionsMySQL.java, issue 211. 
roadmap_1027_li=Test very large databases and LOBs (up to 256 GB). 
roadmap_1028_li=Store all temp files in the temp directory. 
roadmap_1029_li=Don't use temp files, specially not deleteOnExit (bug 4513817\: File.deleteOnExit consumes memory). Also to allow opening client / server (remote) connections when using LOBs. 
roadmap_1030_li=Make DDL (Data Definition) operations transactional. 
roadmap_1031_li=Deferred integrity checking (DEFERRABLE INITIALLY DEFERRED). 
roadmap_1032_li=Groovy Stored Procedures\: http\://groovy.codehaus.org/GSQL 
roadmap_1033_li=Add a migration guide (list differences between databases). 
roadmap_1034_li=Optimization\: automatic index creation suggestion using the trace file? 
roadmap_1035_li=Fulltext search Lucene\: analyzer configuration, mergeFactor. 
roadmap_1036_li=Compression performance\: don't allocate buffers, compress / expand in to out buffer. 
roadmap_1037_li=Rebuild index functionality to shrink index size and improve performance. 
roadmap_1038_li=Console\: add accesskey to most important commands (A, AREA, BUTTON, INPUT, LABEL, LEGEND, TEXTAREA). 
roadmap_1039_li=Test performance again with SQL Server, Oracle, DB2. 
roadmap_1040_li=Test with Spatial DB in a box / JTS\: http\://www.opengeospatial.org/standards/sfs - OpenGIS Implementation Specification. 
roadmap_1041_li=Write more tests and documentation for MVCC (Multi Version Concurrency Control). 
roadmap_1042_li=Find a tool to view large text file (larger than 100 MB), with find, page up and down (like less), truncate before / after. 
roadmap_1043_li=Implement, test, document XAConnection and so on. 
roadmap_1044_li=Pluggable data type (for streaming, hashing, compression, validation, conversion, encryption). 
roadmap_1045_li=CHECK\: find out what makes CHECK\=TRUE slow, move to CHECK2. 
roadmap_1046_li=Drop with invalidate views (so that source code is not lost). Check what other databases do exactly. 
roadmap_1047_li=Index usage for (ID, NAME)\=(1, 'Hi'); document. 
roadmap_1048_li=Set a connection read only (Connection.setReadOnly) or using a connection parameter. 
roadmap_1049_li=Access rights\: finer grained access control (grant access for specific functions). 
roadmap_1050_li=ROW_NUMBER() OVER([PARTITION BY columnName][ORDER BY columnName]). 
roadmap_1051_li=Version check\: docs / web console (using Javascript), and maybe in the library (using TCP/IP). 
roadmap_1052_li=Web server classloader\: override findResource / getResourceFrom. 
roadmap_1053_li=Cost for embedded temporary view is calculated wrong, if result is constant. 
roadmap_1054_li=Count index range query (count(*) where id between 10 and 20). 
roadmap_1055_li=Performance\: update in-place. 
roadmap_1056_li=Clustering\: when a database is back alive, automatically synchronize with the master (requires readable transaction log). 
roadmap_1057_li=Database file name suffix\: a way to use no or a different suffix (for example using a slash). 
roadmap_1058_li=Eclipse plugin. 
roadmap_1059_li=Asynchronous queries to support publish/subscribe\: SELECT ... FOR READ WAIT [maxMillisToWait]. See also MS SQL Server "Query Notification". 
roadmap_1060_li=Fulltext search (native)\: reader / tokenizer / filter. 
roadmap_1061_li=Linked schema using CSV files\: one schema for a directory of files; support indexes for CSV files. 
roadmap_1062_li=iReport to support H2. 
roadmap_1063_li=Include SMTP (mail) client (alert on cluster failure, low disk space,...). 
roadmap_1064_li=Option for SCRIPT to only process one or a set of schemas or tables, and append to a file. 
roadmap_1065_li=JSON parser and functions. 
roadmap_1066_li=Copy database\: tool with config GUI and batch mode, extensible (example\: compare). 
roadmap_1067_li=Document, implement tool for long running transactions using user-defined compensation statements. 
roadmap_1068_li=Support SET TABLE DUAL READONLY. 
roadmap_1069_li=GCJ\: what is the state now? 
roadmap_1070_li=Events for\: database Startup, Connections, Login attempts, Disconnections, Prepare (after parsing), Web Server. See http\://docs.openlinksw.com/virtuoso/fn_dbev_startup.html 
roadmap_1071_li=Optimization\: simpler log compression. 
roadmap_1072_li=Support standard INFORMATION_SCHEMA tables, as defined in http\://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt - specially KEY_COLUMN_USAGE\: http\://dev.mysql.com/doc/refman/5.0/en/information-schema.html, http\://www.xcdsql.org/Misc/INFORMATION_SCHEMA%20With%20Rolenames.gif 
roadmap_1073_li=Compatibility\: in MySQL, HSQLDB, /0.0 is NULL; in PostgreSQL, Derby\: division by zero. HSQLDB\: 0.0e1 / 0.0e1 is NaN. 
roadmap_1074_li=Functional tables should accept parameters from other tables (see FunctionMultiReturn) SELECT * FROM TEST T, P2C(T.A, T.R). 
roadmap_1075_li=Custom class loader to reload functions on demand. 
roadmap_1076_li=Test http\://mysql-je.sourceforge.net/ 
roadmap_1077_li=H2 Console\: the webclient could support more features like phpMyAdmin. 
roadmap_1078_li=Support Oracle functions\: TO_DATE, TO_NUMBER. 
roadmap_1079_li=Work on the Java to C converter. 
roadmap_1080_li=The HELP information schema can be directly exposed in the Console. 
roadmap_1081_li=Maybe use the 0x1234 notation for binary fields, see MS SQL Server. 
roadmap_1082_li=Support Oracle CONNECT BY in some way\: http\://www.adp-gmbh.ch/ora/sql/connect_by.html http\://philip.greenspun.com/sql/trees.html 
roadmap_1083_li=SQL Server 2005, Oracle\: support COUNT(*) OVER(). See http\://www.orafusion.com/art_anlytc.htm 
roadmap_1084_li=SQL 2003\: http\://www.wiscorp.com/sql_2003_standard.zip 
roadmap_1085_li=Version column (number/sequence and timestamp based). 
roadmap_1086_li=Optimize getGeneratedKey\: send last identity after each execute (server). 
roadmap_1087_li=Test and document UPDATE TEST SET (ID, NAME) \= (SELECT ID*10, NAME || '\!' FROM TEST T WHERE T.ID\=TEST.ID). 
roadmap_1088_li=Max memory rows / max undo log size\: use block count / row size not row count. 
roadmap_1089_li=Implement point-in-time recovery. 
roadmap_1090_li=Support PL/SQL (programming language / control flow statements). 
roadmap_1091_li=LIKE\: improved version for larger texts (currently using naive search). 
roadmap_1092_li=Throw an exception when the application calls getInt on a Long (optional). 
roadmap_1093_li=Default date format for input and output (local date constants). 
roadmap_1094_li=Document ROWNUM usage for reports\: SELECT ROWNUM, * FROM (subquery). 
roadmap_1095_li=File system that writes to two file systems (replication, replicating file system). 
roadmap_1096_li=Standalone tool to get relevant system properties and add it to the trace output. 
roadmap_1097_li=Support 'call proc(1\=value)' (PostgreSQL, Oracle). 
roadmap_1098_li=Console\: improve editing data (Tab, Shift-Tab, Enter, Up, Down, Shift+Del?). 
roadmap_1099_li=Console\: autocomplete Ctrl+Space inserts template. 
roadmap_1100_li=Option to encrypt .trace.db file. 
roadmap_1101_li=Auto-Update feature for database, .jar file. 
roadmap_1102_li=ResultSet SimpleResultSet.readFromURL(String url)\: id varchar, state varchar, released timestamp. 
roadmap_1103_li=Partial indexing (see PostgreSQL). 
roadmap_1104_li=Add GUI to build a custom version (embedded, fulltext,...) using build flags. 
roadmap_1105_li=http\://rubyforge.org/projects/hypersonic/ 
roadmap_1106_li=Add a sample application that runs the H2 unit test and writes the result to a file (so it can be included in the user app). 
roadmap_1107_li=Table order\: ALTER TABLE TEST ORDER BY NAME DESC (MySQL compatibility). 
roadmap_1108_li=Backup tool should work with other databases as well. 
roadmap_1109_li=Console\: -ifExists doesn't work for the console. Add a flag to disable other dbs. 
roadmap_1110_li=Check if 'FSUTIL behavior set disablelastaccess 1' improves the performance (fsutil behavior query disablelastaccess). 
roadmap_1111_li=Java static code analysis\: http\://pmd.sourceforge.net/ 
roadmap_1112_li=Java static code analysis\: http\://www.eclipse.org/tptp/ 
roadmap_1113_li=Compatibility for CREATE SCHEMA AUTHORIZATION. 
roadmap_1114_li=Implement Clob / Blob truncate and the remaining functionality. 
roadmap_1115_li=Add multiple columns at the same time with ALTER TABLE .. ADD .. ADD ... 
roadmap_1116_li=File locking\: writing a system property to detect concurrent access from the same VM (different classloaders). 
roadmap_1117_li=Pure SQL triggers (example\: update parent table if the child table is changed). 
roadmap_1118_li=Add H2 to Gem (Ruby install system). 
roadmap_1119_li=Support linked JCR tables. 
roadmap_1120_li=Native fulltext search\: min word length; store word positions. 
roadmap_1121_li=Add an option to the SCRIPT command to generate only portable / standard SQL. 
roadmap_1122_li=Updatable views\: create 'instead of' triggers automatically if possible (simple cases first). 
roadmap_1123_li=Improve create index performance. 
roadmap_1124_li=Compact databases without having to close the database (vacuum). 
roadmap_1125_li=Implement more JDBC 4.0 features. 
roadmap_1126_li=Support TRANSFORM / PIVOT as in MS Access. 
roadmap_1127_li=SELECT * FROM (VALUES (...), (...), ....) AS alias(f1, ...). 
roadmap_1128_li=Support updatable views with join on primary keys (to extend a table). 
roadmap_1129_li=Public interface for functions (not public static). 
roadmap_1130_li=Support reading the transaction log. 
roadmap_1131_li=Feature matrix as in <a href\="http\://www.inetsoftware.de/products/jdbc/mssql/features/default.asp">i-net software</a>. 
roadmap_1132_li=Updatable result set on table without primary key or unique index. 
roadmap_1133_li=Compatibility with Derby and PostgreSQL\: VALUES(1), (2); SELECT * FROM (VALUES (1), (2)) AS myTable(c1). Issue 221. 
roadmap_1134_li=Allow execution time prepare for SELECT * FROM CSVREAD(?, 'columnNameString') 
roadmap_1135_li=Support data type INTERVAL 
roadmap_1136_li=Support nested transactions (possibly using savepoints internally). 
roadmap_1137_li=Add a benchmark for bigger databases, and one for many users. 
roadmap_1138_li=Compression in the result set over TCP/IP. 
roadmap_1139_li=Support curtimestamp (like curtime, curdate). 
roadmap_1140_li=Support ANALYZE {TABLE|INDEX} tableName COMPUTE|ESTIMATE|DELETE STATISTICS ptnOption options. 
roadmap_1141_li=Release locks (shared or exclusive) on demand 
roadmap_1142_li=Support OUTER UNION 
roadmap_1143_li=Support parameterized views (similar to CSVREAD, but using just SQL for the definition) 
roadmap_1144_li=A way (JDBC driver) to map an URL (jdbc\:h2map\:c1) to a connection object 
roadmap_1145_li=Support dynamic linked schema (automatically adding/updating/removing tables) 
roadmap_1146_li=Clustering\: adding a node should be very fast and without interrupting clients (very short lock) 
roadmap_1147_li=Compatibility\: \# is the start of a single line comment (MySQL) but date quote (Access). Mode specific 
roadmap_1148_li=Run benchmarks with Android, Java 7, java -server 
roadmap_1149_li=Optimizations\: faster hash function for strings. 
roadmap_1150_li=DatabaseEventListener\: callback for all operations (including expected time, RUNSCRIPT) and cancel functionality 
roadmap_1151_li=Benchmark\: add a graph to show how databases scale (performance/database size) 
roadmap_1152_li=Implement a SQLData interface to map your data over to a custom object 
roadmap_1153_li=In the MySQL and PostgreSQL mode, use lower case identifiers by default (DatabaseMetaData.storesLowerCaseIdentifiers \= true) 
roadmap_1154_li=Support multiple directories (on different hard drives) for the same database 
roadmap_1155_li=Server protocol\: use challenge response authentication, but client sends hash(user+password) encrypted with response 
roadmap_1156_li=Support EXEC[UTE] (doesn't return a result set, compatible to MS SQL Server) 
roadmap_1157_li=Support native XML data type - see http\://en.wikipedia.org/wiki/SQL/XML 
roadmap_1158_li=Support triggers with a string property or option\: SpringTrigger, OSGITrigger 
roadmap_1159_li=MySQL compatibility\: update test1 t1, test2 t2 set t1.id \= t2.id where t1.id \= t2.id; 
roadmap_1160_li=Ability to resize the cache array when resizing the cache 
roadmap_1161_li=Time based cache writing (one second after writing the log) 
roadmap_1162_li=Check state of H2 driver for DDLUtils\: https\://issues.apache.org/jira/browse/DDLUTILS-185 
roadmap_1163_li=Index usage for REGEXP LIKE. 
roadmap_1164_li=Compatibility\: add a role DBA (like ADMIN). 
roadmap_1165_li=Better support multiple processors for in-memory databases. 
roadmap_1166_li=Support N'text' 
roadmap_1167_li=Support compatibility for jdbc\:hsqldb\:res\: 
roadmap_1168_li=HSQLDB compatibility\: automatically convert to the next 'higher' data type. Example\: cast(2000000000 as int) + cast(2000000000 as int); (HSQLDB\: long; PostgreSQL\: integer out of range) 
roadmap_1169_li=Provide an Java SQL builder with standard and H2 syntax 
roadmap_1170_li=Trace\: write OS, file system, JVM,... when opening the database 
roadmap_1171_li=Support indexes for views (probably requires materialized views) 
roadmap_1172_li=Document SET SEARCH_PATH, BEGIN, EXECUTE, parameters 
roadmap_1173_li=Server\: use one listener (detect if the request comes from an PG or TCP client) 
roadmap_1174_li=Optimize SELECT MIN(ID), MAX(ID), COUNT(*) FROM TEST WHERE ID BETWEEN 100 AND 200 
roadmap_1175_li=Sequence\: PostgreSQL compatibility (rename, create) http\://www.postgresql.org/docs/8.2/static/sql-altersequence.html 
roadmap_1176_li=DISTINCT\: support large result sets by sorting on all columns (additionally) and then removing duplicates. 
roadmap_1177_li=Support a special trigger on all tables to allow building a transaction log reader. 
roadmap_1178_li=File system with a background writer thread; test if this is faster 
roadmap_1179_li=Better document the source code (high level documentation). 
roadmap_1180_li=Support select * from dual a left join dual b on b.x\=(select max(x) from dual) 
roadmap_1181_li=Optimization\: don't lock when the database is read-only 
roadmap_1182_li=Issue 146\: Support merge join. 
roadmap_1183_li=Integrate spatial functions from http\://geosysin.iict.ch/irstv-trac/wiki/H2spatial/Download 
roadmap_1184_li=Cluster\: hot deploy (adding a node at runtime). 
roadmap_1185_li=Support DatabaseMetaData.insertsAreDetected\: updatable result sets should detect inserts. 
roadmap_1186_li=Oracle\: support DECODE method (convert to CASE WHEN). 
roadmap_1187_li=Native search\: support "phrase search", wildcard search (* and ?), case-insensitive search, boolean operators, and grouping 
roadmap_1188_li=Improve documentation of access rights. 
roadmap_1189_li=Support opening a database that is in the classpath, maybe using a new file system. Workaround\: detect jar file using getClass().getProtectionDomain().getCodeSource().getLocation(). 
roadmap_1190_li=Support ENUM data type (see MySQL, PostgreSQL, MS SQL Server, maybe others). 
roadmap_1191_li=Remember the user defined data type (domain) of a column. 
roadmap_1192_li=MVCC\: support multi-threaded kernel with multi-version concurrency. 
roadmap_1193_li=Auto-server\: add option to define the port range or list. 
roadmap_1194_li=Support Jackcess (MS Access databases) 
roadmap_1195_li=Built-in methods to write large objects (BLOB and CLOB)\: FILE_WRITE('test.txt', 'Hello World') 
roadmap_1196_li=Improve time to open large databases (see mail 'init time for distributed setup') 
roadmap_1197_li=Move Maven 2 repository from hsql.sf.net to h2database.sf.net 
roadmap_1198_li=Java 1.5 tool\: JdbcUtils.closeSilently(s1, s2,...) 
roadmap_1199_li=Optimize A\=? OR B\=? to UNION if the cost is lower. 
roadmap_1200_li=Javadoc\: document design patterns used 
roadmap_1201_li=Support custom collators, for example for natural sort (for text that contains numbers). 
roadmap_1202_li=Write an article about SQLInjection (h2/src/docsrc/html/images/SQLInjection.txt) 
roadmap_1203_li=Convert SQL-injection-2.txt to html document, include SQLInjection.java sample 
roadmap_1204_li=Support OUT parameters in user-defined procedures. 
roadmap_1205_li=Web site design\: http\://www.igniterealtime.org/projects/openfire/index.jsp 
roadmap_1206_li=HSQLDB compatibility\: Openfire server uses\: CREATE SCHEMA PUBLIC AUTHORIZATION DBA; CREATE USER SA PASSWORD ""; GRANT DBA TO SA; SET SCHEMA PUBLIC 
roadmap_1207_li=Translation\: use ?? in help.csv 
roadmap_1208_li=Translated .pdf 
roadmap_1209_li=Recovery tool\: bad blocks should be converted to INSERT INTO SYSTEM_ERRORS(...), and things should go into the .trace.db file 
roadmap_1210_li=Issue 357\: support getGeneratedKeys to return multiple rows when used with batch updates. This is supported by MySQL, but not Derby. Both PostgreSQL and HSQLDB don't support getGeneratedKeys. Also support it when using INSERT ... SELECT. 
roadmap_1211_li=RECOVER\=2 to backup the database, run recovery, open the database 
roadmap_1212_li=Recovery should work with encrypted databases 
roadmap_1213_li=Corruption\: new error code, add help 
roadmap_1214_li=Space reuse\: after init, scan all storages and free those that don't belong to a live database object 
roadmap_1215_li=Access rights\: add missing features (users should be 'owner' of objects; missing rights for sequences; dropping objects) 
roadmap_1216_li=Support NOCACHE table option (Oracle). 
roadmap_1217_li=Support table partitioning. 
roadmap_1218_li=Add regular javadocs (using the default doclet, but another css) to the homepage. 
roadmap_1219_li=The database should be kept open for a longer time when using the server mode. 
roadmap_1220_li=Javadocs\: for each tool, add a copy &amp; paste sample in the class level. 
roadmap_1221_li=Javadocs\: add @author tags. 
roadmap_1222_li=Fluent API for tools\: Server.createTcpServer().setPort(9081).setPassword(password).start(); 
roadmap_1223_li=MySQL compatibility\: real SQL statement for DESCRIBE TEST 
roadmap_1224_li=Use a default delay of 1 second before closing a database. 
roadmap_1225_li=Write (log) to system table before adding to internal data structures. 
roadmap_1226_li=Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup). 
roadmap_1227_li=Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object) (with test case). 
roadmap_1228_li=MVCC should not be memory bound (uncommitted data is kept in memory in the delta index; maybe using a regular b-tree index solves the problem). 
roadmap_1229_li=Oracle compatibility\: support NLS_DATE_FORMAT. 
roadmap_1230_li=Support for Thread.interrupt to cancel running statements. 
roadmap_1231_li=Cluster\: add feature to make sure cluster nodes can not get out of sync (for example by stopping one process). 
roadmap_1232_li=H2 Console\: support CLOB/BLOB download using a link. 
roadmap_1233_li=Support flashback queries as in Oracle. 
roadmap_1234_li=Import / Export of fixed with text files. 
roadmap_1235_li=HSQLDB compatibility\: automatic data type for SUM if value is the value is too big (by default use the same type as the data). 
roadmap_1236_li=Improve the optimizer to select the right index for special cases\: where id between 2 and 4 and booleanColumn 
roadmap_1237_li=Linked tables\: make hidden columns available (Oracle\: rowid and ora_rowscn columns). 
roadmap_1238_li=H2 Console\: in-place autocomplete. 
roadmap_1239_li=Support large databases\: split database files to multiple directories / disks (similar to tablespaces). 
roadmap_1240_li=H2 Console\: support configuration option for fixed width (monospace) font. 
roadmap_1241_li=Native fulltext search\: support analyzers (specially for Chinese, Japanese). 
roadmap_1242_li=Automatically compact databases from time to time (as a background process). 
roadmap_1243_li=Test Eclipse DTP. 
roadmap_1244_li=H2 Console\: autocomplete\: keep the previous setting 
roadmap_1245_li=executeBatch\: option to stop at the first failed statement. 
roadmap_1246_li=Implement OLAP features as described here\: http\://www.devx.com/getHelpOn/10MinuteSolution/16573/0/page/5 
roadmap_1247_li=Support Oracle ROWID (unique identifier for each row). 
roadmap_1248_li=MySQL compatibility\: alter table add index i(c), add constraint c foreign key(c) references t(c); 
roadmap_1249_li=Server mode\: improve performance for batch updates. 
roadmap_1250_li=Applets\: support read-only databases in a zip file (accessed as a resource). 
roadmap_1251_li=Long running queries / errors / trace system table. 
roadmap_1252_li=H2 Console should support JaQu directly. 
roadmap_1253_li=Better document FTL_SEARCH, FTL_SEARCH_DATA. 
roadmap_1254_li=Sequences\: CURRVAL should be session specific. Compatibility with PostgreSQL. 
roadmap_1255_li=Index creation using deterministic functions. 
roadmap_1256_li=ANALYZE\: for unique indexes that allow null, count the number of null. 
roadmap_1257_li=MySQL compatibility\: multi-table delete\: DELETE .. FROM .. [,...] USING - See http\://dev.mysql.com/doc/refman/5.0/en/delete.html 
roadmap_1258_li=AUTO_SERVER\: support changing IP addresses (disable a network while the database is open). 
roadmap_1259_li=Avoid using java.util.Calendar internally because it's slow, complicated, and buggy. 
roadmap_1260_li=Support TRUNCATE .. CASCADE like PostgreSQL. 
roadmap_1261_li=Fulltext search\: lazy result generation using SimpleRowSource. 
roadmap_1262_li=Fulltext search\: support alternative syntax\: WHERE FTL_CONTAINS(name, 'hello'). 
roadmap_1263_li=MySQL compatibility\: support REPLACE, see http\://dev.mysql.com/doc/refman/6.0/en/replace.html and issue 73. 
roadmap_1264_li=MySQL compatibility\: support INSERT INTO table SET column1 \= value1, column2 \= value2 
roadmap_1265_li=Docs\: add a one line description for each functions and SQL statements at the top (in the link section). 
roadmap_1266_li=Javadoc search\: weight for titles should be higher ('random' should list Functions as the best match). 
roadmap_1267_li=Replace information_schema tables with regular tables that are automatically re-built when needed. Use indexes. 
roadmap_1268_li=Issue 50\: Oracle compatibility\: support calling 0-parameters functions without parenthesis. Make constants obsolete. 
roadmap_1269_li=MySQL, HSQLDB compatibility\: support where 'a'\=1 (not supported by Derby, PostgreSQL) 
roadmap_1270_li=Support a data type "timestamp with timezone" using java.util.Calendar. 
roadmap_1271_li=Finer granularity for SLF4J trace - See http\://code.google.com/p/h2database/issues/detail?id\=62 
roadmap_1272_li=Add database creation date and time to the database. 
roadmap_1273_li=Support ASSERTION. 
roadmap_1274_li=MySQL compatibility\: support comparing 1\='a' 
roadmap_1275_li=Support PostgreSQL lock modes\: http\://www.postgresql.org/docs/8.3/static/explicit-locking.html 
roadmap_1276_li=PostgreSQL compatibility\: test DbVisualizer and Squirrel SQL using a new PostgreSQL JDBC driver. 
roadmap_1277_li=RunScript should be able to read from system in (or quite mode for Shell). 
roadmap_1278_li=Natural join\: support select x from dual natural join dual. 
roadmap_1279_li=Support using system properties in database URLs (may be a security problem). 
roadmap_1280_li=Natural join\: somehow support this\: select a.x, b.x, x from dual a natural join dual b 
roadmap_1281_li=Use the Java service provider mechanism to register file systems and function libraries. 
roadmap_1282_li=MySQL compatibility\: for auto_increment columns, convert 0 to next value (as when inserting NULL). 
roadmap_1283_li=Optimization for multi-column IN\: use an index if possible. Example\: (A, B) IN((1, 2), (2, 3)). 
roadmap_1284_li=Optimization for EXISTS\: convert to inner join or IN(..) if possible. 
roadmap_1285_li=Functions\: support hashcode(value); cryptographic and fast 
roadmap_1286_li=Serialized file lock\: support long running queries. 
roadmap_1287_li=Network\: use 127.0.0.1 if other addresses don't work. 
roadmap_1288_li=Pluggable network protocol (currently Socket/ServerSocket over TCP/IP) - see also TransportServer with master slave replication. 
roadmap_1289_li=Support reading JCR data\: one table per node type; query table; cache option 
roadmap_1290_li=OSGi\: create a sample application, test, document. 
roadmap_1291_li=help.csv\: use complete examples for functions; run as test case. 
roadmap_1292_li=Functions to calculate the memory and disk space usage of a table, a row, or a value. 
roadmap_1293_li=Re-implement PooledConnection; use a lightweight connection object. 
roadmap_1294_li=Doclet\: convert tests in javadocs to a java class. 
roadmap_1295_li=Doclet\: format fields like methods, but support sorting by name and value. 
roadmap_1296_li=Doclet\: shrink the html files. 
roadmap_1297_li=MySQL compatibility\: support SET NAMES 'latin1' - See also http\://code.google.com/p/h2database/issues/detail?id\=56 
roadmap_1298_li=Allow to scan index backwards starting with a value (to better support ORDER BY DESC). 
roadmap_1299_li=Java Service Wrapper\: try http\://yajsw.sourceforge.net/ 
roadmap_1300_li=Batch parameter for INSERT, UPDATE, and DELETE, and commit after each batch. See also MySQL DELETE. 
roadmap_1301_li=MySQL compatibility\: support ALTER TABLE .. MODIFY COLUMN. 
roadmap_1302_li=Use a lazy and auto-close input stream (open resource when reading, close on eof). 
roadmap_1303_li=PostgreSQL compatibility\: generate_series. 
roadmap_1304_li=Connection pool\: 'reset session' command (delete temp tables, rollback, auto-commit true). 
roadmap_1305_li=Improve SQL documentation, see http\://www.w3schools.com/sql/ 
roadmap_1306_li=MySQL compatibility\: DatabaseMetaData.stores*() methods should return the same values. Test with SquirrelSQL. 
roadmap_1307_li=MS SQL Server compatibility\: support DATEPART syntax. 
roadmap_1308_li=Sybase/DB2/Oracle compatibility\: support out parameters in stored procedures - See http\://code.google.com/p/h2database/issues/detail?id\=83 
roadmap_1309_li=Support INTERVAL data type (see Oracle and others). 
roadmap_1310_li=Combine Server and Console tool (only keep Server). 
roadmap_1311_li=Store the Lucene index in the database itself. 
roadmap_1312_li=Support standard MERGE statement\: http\://en.wikipedia.org/wiki/Merge_%28SQL%29 
roadmap_1313_li=Oracle compatibility\: support DECODE(x, ...). 
roadmap_1314_li=MVCC\: compare concurrent update behavior with PostgreSQL and Oracle. 
roadmap_1315_li=HSQLDB compatibility\: CREATE FUNCTION (maybe using a Function interface). 
roadmap_1316_li=HSQLDB compatibility\: support CALL "java.lang.Math.sqrt"(2.0) 
roadmap_1317_li=Support comma as the decimal separator in the CSV tool. 
roadmap_1318_li=Compatibility\: Java functions with SQLJ Part1 http\://www.acm.org/sigmod/record/issues/9912/standards.pdf.gz 
roadmap_1319_li=Compatibility\: Java functions with SQL/PSM (Persistent Stored Modules) - need to find the documentation. 
roadmap_1320_li=CACHE_SIZE\: automatically use a fraction of Runtime.maxMemory - maybe automatically the second level cache. 
roadmap_1321_li=Support date/time/timestamp as documented in http\://en.wikipedia.org/wiki/ISO_8601 
roadmap_1322_li=PostgreSQL compatibility\: when in PG mode, treat BYTEA data like PG. 
roadmap_1323_li=Support \=ANY(array) as in PostgreSQL. See also http\://www.postgresql.org/docs/8.0/interactive/arrays.html 
roadmap_1324_li=IBM DB2 compatibility\: support PREVIOUS VALUE FOR sequence. 
roadmap_1325_li=Compatibility\: use different LIKE ESCAPE characters depending on the mode (disable for Derby, HSQLDB, DB2, Oracle, MSSQLServer). 
roadmap_1326_li=Oracle compatibility\: support CREATE SYNONYM table FOR schema.table. 
roadmap_1327_li=FTP\: document the server, including -ftpTask option to execute / kill remote processes 
roadmap_1328_li=FTP\: problems with multithreading? 
roadmap_1329_li=FTP\: implement SFTP / FTPS 
roadmap_1330_li=FTP\: access to a database (.csv for a table, a directory for a schema, a file for a lob, a script.sql file). 
roadmap_1331_li=More secure default configuration if remote access is enabled. 
roadmap_1332_li=Improve database file locking (maybe use native file locking). The current approach seems to be problematic if the file system is on a remote share (see Google Group 'Lock file modification time is in the future'). 
roadmap_1333_li=Document internal features such as BELONGS_TO_TABLE, NULL_TO_DEFAULT, SEQUENCE. 
roadmap_1334_li=Issue 107\: Prefer using the ORDER BY index if LIMIT is used. 
roadmap_1335_li=An index on (id, name) should be used for a query\: select * from t where s\=? order by i 
roadmap_1336_li=Support reading sequences using DatabaseMetaData.getTables(null, null, null, new String[]{"SEQUENCE"}). See PostgreSQL. 
roadmap_1337_li=Add option to enable TCP_NODELAY using Socket.setTcpNoDelay(true). 
roadmap_1338_li=Maybe disallow \= within database names (jdbc\:h2\:mem\:MODE\=DB2 means database name MODE\=DB2). 
roadmap_1339_li=Fast alter table add column. 
roadmap_1340_li=Improve concurrency for in-memory database operations. 
roadmap_1341_li=Issue 122\: Support for connection aliases for remote tcp connections. 
roadmap_1342_li=Fast scrambling (strong encryption doesn't help if the password is included in the application). 
roadmap_1343_li=H2 Console\: support -webPassword to require a password to access preferences or shutdown. 
roadmap_1344_li=Issue 126\: The index name should be "IDX_" plus the constraint name unless there is a conflict, in which case append a number. 
roadmap_1345_li=Issue 127\: Support activation/deactivation of triggers 
roadmap_1346_li=Issue 130\: Custom log event listeners 
roadmap_1347_li=Issue 131\: IBM DB2 compatibility\: sysibm.sysdummy1 
roadmap_1348_li=Issue 132\: Use Java enum trigger type. 
roadmap_1349_li=Issue 134\: IBM DB2 compatibility\: session global variables. 
roadmap_1350_li=Cluster\: support load balance with values for each server / auto detect. 
roadmap_1351_li=FTL_SET_OPTION(keyString, valueString) with key stopWords at first. 
roadmap_1352_li=Pluggable access control mechanism. 
roadmap_1353_li=Fulltext search (Lucene)\: support streaming CLOB data. 
roadmap_1354_li=Document/example how to create and read an encrypted script file. 
roadmap_1355_li=Check state of https\://issues.apache.org/jira/browse/OPENJPA-1367 (H2 does support cross joins). 
roadmap_1356_li=Fulltext search (Lucene)\: only prefix column names with _ if they already start with _. Instead of DATA / QUERY / modified use _DATA, _QUERY, _MODIFIED if possible. 
roadmap_1357_li=Support a way to create or read compressed encrypted script files using an API. 
roadmap_1358_li=Scripting language support (Javascript). 
roadmap_1359_li=The network client should better detect if the server is not an H2 server and fail early. 
roadmap_1360_li=H2 Console\: support CLOB/BLOB upload. 
roadmap_1361_li=Database file lock\: detect hibernate / standby / very slow threads (compare system time). 
roadmap_1362_li=Automatic detection of redundant indexes. 
roadmap_1363_li=Maybe reject join without "on" (except natural join). 
roadmap_1364_li=Implement GiST (Generalized Search Tree for Secondary Storage). 
roadmap_1365_li=Function to read a number of bytes/characters from an BLOB or CLOB. 
roadmap_1366_li=Issue 156\: Support SELECT ? UNION SELECT ?. 
roadmap_1367_li=Automatic mixed mode\: support a port range list (to avoid firewall problems). 
roadmap_1368_li=Support the pseudo column rowid, oid, _rowid_. 
roadmap_1369_li=H2 Console / large result sets\: stream early instead of keeping a whole result in-memory 
roadmap_1370_li=Support TRUNCATE for linked tables. 
roadmap_1371_li=UNION\: evaluate INTERSECT before UNION (like most other database except Oracle). 
roadmap_1372_li=Delay creating the information schema, and share metadata columns. 
roadmap_1373_li=TCP Server\: use a nonce (number used once) to protect unencrypted channels against replay attacks. 
roadmap_1374_li=Simplify running scripts and recovery\: CREATE FORCE USER (overwrites an existing user). 
roadmap_1375_li=Support CREATE DATABASE LINK (a custom JDBC driver is already supported). 
roadmap_1376_li=Support large GROUP BY operations. Issue 216. 
roadmap_1377_li=Issue 163\: Allow to create foreign keys on metadata types. 
roadmap_1378_li=Logback\: write a native DBAppender. 
roadmap_1379_li=Cache size\: don't use more cache than what is available. 
roadmap_1380_li=Allow to defragment at runtime (similar to SHUTDOWN DEFRAG) in a background thread. 
roadmap_1381_li=Tree index\: Instead of an AVL tree, use a general balanced trees or a scapegoat tree. 
roadmap_1382_li=User defined functions\: allow to store the bytecode (of just the class, or the jar file of the extension) in the database. 
roadmap_1383_li=Compatibility\: ResultSet.getObject() on a CLOB (TEXT) should return String for PostgreSQL and MySQL. 
roadmap_1384_li=Optimizer\: WHERE X\=? AND Y IN(?), it always uses the index on Y. Should be cost based. 
roadmap_1385_li=Common Table Expression (CTE) / recursive queries\: support parameters. Issue 314. 
roadmap_1386_li=Oracle compatibility\: support INSERT ALL. 
roadmap_1387_li=Issue 178\: Optimizer\: index usage when both ascending and descending indexes are available. 
roadmap_1388_li=Issue 179\: Related subqueries in HAVING clause. 
roadmap_1389_li=IBM DB2 compatibility\: NOT NULL WITH DEFAULT. Similar to MySQL Mode.convertInsertNullToZero. 
roadmap_1390_li=Creating primary key\: always create a constraint. 
roadmap_1391_li=Maybe use a different page layout\: keep the data at the head of the page, and ignore the tail (don't store / read it). This may increase write / read performance depending on the file system. 
roadmap_1392_li=Indexes of temporary tables are currently kept in-memory. Is this how it should be? 
roadmap_1393_li=The Shell tool should support the same built-in commands as the H2 Console. 
roadmap_1394_li=Maybe use PhantomReference instead of finalize. 
roadmap_1395_li=Database file name suffix\: should only have one dot by default. Example\: .h2db 
roadmap_1396_li=Issue 196\: Function based indexes 
roadmap_1397_li=ALTER TABLE ... ADD COLUMN IF NOT EXISTS columnName. 
roadmap_1398_li=Fix the disk space leak (killing the process at the exact right moment will increase the disk space usage; this space is not re-used). See TestDiskSpaceLeak.java 
roadmap_1399_li=ROWNUM\: Oracle compatibility when used within a subquery. Issue 198. 
roadmap_1400_li=Allow to access the database over HTTP (possibly using port 80) and a servlet in a REST way. 
roadmap_1401_li=ODBC\: encrypted databases are not supported because the ;CIPHER\= can not be set. 
roadmap_1402_li=Support CLOB and BLOB update, specially conn.createBlob().setBinaryStream(1); 
roadmap_1403_li=Optimizer\: index usage when both ascending and descending indexes are available. Issue 178. 
roadmap_1404_li=Issue 306\: Support schema specific domains. 
roadmap_1405_li=Triggers\: support user defined execution order. Oracle\: CREATE OR REPLACE TRIGGER TEST_2 BEFORE INSERT ON TEST FOR EACH ROW FOLLOWS TEST_1. SQL specifies that multiple triggers should be fired in time-of-creation order. PostgreSQL uses name order, which was judged to be more convenient. Derby\: triggers are fired in the order in which they were created. 
roadmap_1406_li=PostgreSQL compatibility\: combine "users" and "roles". See\: http\://www.postgresql.org/docs/8.1/interactive/user-manag.html 
roadmap_1407_li=Improve documentation of system properties\: only list the property names, default values, and description. 
roadmap_1408_li=Support running totals / cumulative sum using SUM(..) OVER(..). 
roadmap_1409_li=Improve object memory size calculation. Use constants for known VMs, or use reflection to call java.lang.instrument.Instrumentation.getObjectSize(Object objectToSize) 
roadmap_1410_li=Triggers\: NOT NULL checks should be done after running triggers (Oracle behavior, maybe others). 
roadmap_1411_li=Common Table Expression (CTE) / recursive queries\: support INSERT INTO ... SELECT ... Issue 219. 
roadmap_1412_li=Common Table Expression (CTE) / recursive queries\: support non-recursive queries. Issue 217. 
roadmap_1413_li=Common Table Expression (CTE) / recursive queries\: avoid endless loop. Issue 218. 
roadmap_1414_li=Common Table Expression (CTE) / recursive queries\: support multiple named queries. Issue 220. 
roadmap_1415_li=Common Table Expression (CTE) / recursive queries\: identifier scope may be incorrect. Issue 222. 
roadmap_1416_li=Log long running transactions (similar to long running statements). 
roadmap_1417_li=Parameter data type is data type of other operand. Issue 205. 
roadmap_1418_li=Some combinations of nested join with right outer join are not supported. 
roadmap_1419_li=DatabaseEventListener.openConnection(id) and closeConnection(id). 
roadmap_1420_li=Listener or authentication module for new connections, or a way to restrict the number of different connections to a tcp server, or to prevent to login with the same username and password from different IPs. Possibly using the DatabaseEventListener API, or a new API. 
roadmap_1421_li=Compatibility for data type CHAR (Derby, HSQLDB). Issue 212. 
roadmap_1422_li=Compatibility with MySQL TIMESTAMPDIFF. Issue 209. 
roadmap_1423_li=Optimizer\: use a histogram of the data, specially for non-normal distributions. 
roadmap_1424_li=Trigger\: allow declaring as source code (like functions). 
roadmap_1425_li=User defined aggregate\: allow declaring as source code (like functions). 
roadmap_1426_li=The error "table not found" is sometimes caused by using the wrong database. Add "(this database is empty)" to the exception message if applicable. 
roadmap_1427_li=MySQL + PostgreSQL compatibility\: support string literal escape with \\n. 
roadmap_1428_li=PostgreSQL compatibility\: support string literal escape with double \\\\. 
roadmap_1429_li=Document the TCP server "management_db". Maybe include the IP address of the client. 
roadmap_1430_li=Use javax.tools.JavaCompilerTool instead of com.sun.tools.javac.Main 
roadmap_1431_li=If a database object was not found in the current schema, but one with the same name existed in another schema, included that in the error message. 
roadmap_1432_li=Optimization to use an index for OR when using multiple keys\: where (key1 \= ? and key2 \= ?) OR (key1 \= ? and key2 \= ?) 
roadmap_1433_li=Issue 302\: Support optimizing queries with both inner and outer joins, as in\: select * from test a inner join test b on a.id\=b.id inner join o on o.id\=a.id where b.x\=1 (the optimizer should swap a and b here). See also TestNestedJoins, tag "swapInnerJoinTables". 
roadmap_1434_li=JaQu should support a DataSource and a way to create a Db object using a Connection (for multi-threaded usage with a connection pool). 
roadmap_1435_li=Move table to a different schema (rename table to a different schema), possibly using ALTER TABLE ... SET SCHEMA ...; 
roadmap_1436_li=nioMapped file system\: automatically fall back to regular (non mapped) IO if there is a problem (out of memory exception for example). 
roadmap_1437_li=Column as parameter of function table. Issue 228. 
roadmap_1438_li=Connection pool\: detect ;AUTOCOMMIT\=FALSE in the database URL, and if set, disable autocommit for all connections. 
roadmap_1439_li=Compatibility with MS Access\: support "&amp;" to concatenate text. 
roadmap_1440_li=The BACKUP statement should not synchronize on the database, and therefore should not block other users. 
roadmap_1441_li=Document the database file format. 
roadmap_1442_li=Support reading LOBs. 
roadmap_1443_li=Require appending DANGEROUS\=TRUE when using certain dangerous settings such as LOG\=0, LOG\=1, LOCK_MODE\=0, disabling FILE_LOCK,... 
roadmap_1444_li=Support UDT (user defined types) similar to how Apache Derby supports it\: check constraint, allow to use it in Java functions as parameters (return values already seem to work). 
roadmap_1445_li=Encrypted file system (use cipher text stealing so file length doesn't need to decrypt; 4 KB header per file, optional compatibility with current encrypted database files). 
roadmap_1446_li=Issue 229\: SELECT with simple OR tests uses tableScan when it could use indexes. 
roadmap_1447_li=GROUP BY queries should use a temporary table if there are too many rows. 
roadmap_1448_li=BLOB\: support random access when reading. 
roadmap_1449_li=CLOB\: support random access when reading (this is harder than for BLOB as data is stored in UTF-8 form). 
roadmap_1450_li=Compatibility\: support SELECT INTO (as an alias for CREATE TABLE ... AS SELECT ...). 
roadmap_1451_li=Compatibility with MySQL\: support SELECT INTO OUTFILE (cannot be an existing file) as an alias for CSVWRITE(...). 
roadmap_1452_li=Compatibility with MySQL\: support non-strict mode (sql_mode \= "") any data that is too large for the column will just be truncated or set to the default value. 
roadmap_1453_li=The full condition should be sent to the linked table, not just the indexed condition. Example\: TestLinkedTableFullCondition 
roadmap_1454_li=Compatibility with IBM DB2\: CREATE PROCEDURE. 
roadmap_1455_li=Compatibility with IBM DB2\: SQL cursors. 
roadmap_1456_li=Single-column primary key values are always stored explicitly. This is not required. 
roadmap_1457_li=Compatibility with MySQL\: support CREATE TABLE TEST(NAME VARCHAR(255) CHARACTER SET UTF8). 
roadmap_1458_li=CALL is incompatible with other databases because it returns a result set, so that CallableStatement.execute() returns true. 
roadmap_1459_li=Optimization for large lists for column IN(1, 2, 3, 4,...) - currently an list is used, could potentially use a hash set (maybe only for a part of the values - the ones that can be evaluated). 
roadmap_1460_li=Compatibility for ARRAY data type (Oracle\: VARRAY(n) of VARCHAR(m); HSQLDB\: VARCHAR(n) ARRAY; Postgres\: VARCHAR(n)[]). 
roadmap_1461_li=PostgreSQL compatible array literal syntax\: ARRAY[['a', 'b'], ['c', 'd']] 
roadmap_1462_li=PostgreSQL compatibility\: UPDATE with FROM. 
roadmap_1463_li=Issue 297\: Oracle compatibility for "at time zone". 
roadmap_1464_li=IBM DB2 compatibility\: IDENTITY_VAL_LOCAL(). 
roadmap_1465_li=Support SQL/XML. 
roadmap_1466_li=Support concurrent opening of databases. 
roadmap_1467_li=Improved error message and diagnostics in case of network configuration problems. 
roadmap_1468_li=TRUNCATE should reset the identity columns as in MySQL and MS SQL Server (and possibly other databases). 
roadmap_1469_li=Adding a primary key should make the columns 'not null' unless if there is a row with null (compatibility with MySQL, PostgreSQL, HSQLDB; not Derby). 
roadmap_1470_li=ARRAY data type\: support Integer[] and so on in Java functions (currently only Object[] is supported). 
roadmap_1471_li=MySQL compatibility\: LOCK TABLES a READ, b READ - see also http\://dev.mysql.com/doc/refman/5.0/en/lock-tables.html 
roadmap_1472_li=The HTML to PDF converter should use http\://code.google.com/p/wkhtmltopdf/ 
roadmap_1473_li=Issue 303\: automatically convert "X NOT IN(SELECT...)" to "NOT EXISTS(...)". 
roadmap_1474_li=MySQL compatibility\: update test1 t1, test2 t2 set t1.name\=t2.name where t1.id\=t2.id. 
roadmap_1475_li=Issue 283\: Improve performance of H2 on Android. 
roadmap_1476_li=Support INSERT INTO / UPDATE / MERGE ... RETURNING to retrieve the generated key(s). 
roadmap_1477_li=Column compression option - see http\://groups.google.com/group/h2-database/browse_thread/thread/3e223504e52671fa/243da82244343f5d 
roadmap_1478_li=PostgreSQL compatibility\: ALTER TABLE ADD combined with adding a foreign key constraint, as in ALTER TABLE FOO ADD COLUMN PARENT BIGINT REFERENCES FOO(ID). 
roadmap_1479_li=MS SQL Server compatibility\: support @@ROWCOUNT. 
roadmap_1480_li=PostgreSQL compatibility\: LOG(x) is LOG10(x) and not LN(x). 
roadmap_1481_li=Issue 311\: Serialized lock mode\: executeQuery of write operations fails. 
roadmap_1482_li=PostgreSQL compatibility\: support PgAdmin III (specially the function current_setting). 
roadmap_1483_li=MySQL compatibility\: support TIMESTAMPADD. 
roadmap_1484_li=Support SELECT ... FOR UPDATE with joins (supported by PostgreSQL, MySQL, and HSQLDB; but not Derby). 
roadmap_1485_li=Support SELECT ... FOR UPDATE OF [field-list] (supported by PostgreSQL, MySQL, and HSQLDB; but not Derby). 
roadmap_1486_li=Support SELECT ... FOR UPDATE OF [table-list] (supported by PostgreSQL, HSQLDB, Sybase). 
roadmap_1487_li=TRANSACTION_ID() for in-memory databases. 
roadmap_1488_li=TRANSACTION_ID() should be long (same as HSQLDB and PostgreSQL). 
roadmap_1489_li=Support [INNER | OUTER] JOIN USING(column [,...]). 
roadmap_1490_li=Support NATURAL [ { LEFT | RIGHT } [ OUTER ] | INNER ] JOIN (Derby, Oracle) 
roadmap_1491_li=GROUP BY columnNumber (similar to ORDER BY columnNumber) (MySQL, PostgreSQL, SQLite; not by HSQLDB and Derby). 
roadmap_1492_li=Sybase / MS SQL Server compatibility\: CONVERT(..) parameters are swapped. 
roadmap_1493_li=Index conditions\: WHERE AGE>1 should not scan through all rows with AGE\=1. 
roadmap_1494_li=PHP support\: H2 should support PDO, or test with PostgreSQL PDO. 
roadmap_1495_li=Outer joins\: if no column of the outer join table is referenced, the outer join table could be removed from the query. 
roadmap_1496_li=Cluster\: allow using auto-increment and identity columns by ensuring executed in lock-step. 
roadmap_1497_li=MySQL compatibility\: index names only need to be unique for the given table. 
roadmap_1498_li=Issue 352\: constraints\: distinguish between 'no action' and 'restrict'. Currently, only restrict is supported, and 'no action' is internally mapped to 'restrict'. The database meta data returns 'restrict' in all cases. 
roadmap_1499_li=Oracle compatibility\: support MEDIAN aggregate function. 
roadmap_1500_li=Issue 348\: Oracle compatibility\: division should return a decimal result. 
roadmap_1501_li=Read rows on demand\: instead of reading the whole row, only read up to that column that is requested. Keep an pointer to the data area and the column id that is already read. 
roadmap_1502_li=Long running transactions\: log session id when detected. 
roadmap_1503_li=Optimization\: "select id from test" should use the index on id even without "order by". 
roadmap_1504_li=Issue 362\: LIMIT support for UPDATE statements (MySQL compatibility). 
roadmap_1505_li=Sybase SQL Anywhere compatibility\: SELECT TOP ... START AT ... 
roadmap_1506_li=Use Java 6 SQLException subclasses. 
roadmap_1507_li=Issue 390\: RUNSCRIPT FROM '...' CONTINUE_ON_ERROR 
roadmap_1508_li=Use Java 6 exceptions\: SQLDataException, SQLSyntaxErrorException, SQLTimeoutException,.. 
roadmap_1509_h2=Not Planned
roadmap_1510_li=HSQLDB (did) support this\: select id i from test where i&lt;0 (other databases don't). Supporting it may break compatibility. 
roadmap_1511_li=String.intern (so that Strings can be compared with \=\=) will not be used because some VMs have problems when used extensively. 
roadmap_1512_li=In prepared statements, identifier names (table names and so on) can not be parameterized. Adding such a feature would complicate the source code without providing reasonable speedup, and would slow down regular prepared statements. 
sourceError_1000_h1=Error Analyzer
sourceError_1001_a=Home
sourceError_1002_a=Input
sourceError_1003_h2=&nbsp; <a href\="javascript\:select('details')" id \= "detailsTab">Details</a>&nbsp; <a href\="javascript\:select('source')" id \= "sourceTab">Source Code</a> 
sourceError_1004_p=Paste the error message and stack trace below and click on 'Details' or 'Source Code'\: 
sourceError_1005_b=Error Code\: 
sourceError_1006_b=Product Version\: 
sourceError_1007_b=Message\: 
sourceError_1008_b=More Information\:
sourceError_1009_b=Stack Trace\: 
sourceError_1010_b=Source File\: 
sourceError_1011_p=\ Inline 
tutorial_1000_h1=Tutorial
tutorial_1001_a=\ Starting and Using the H2 Console
tutorial_1002_a=\ Special H2 Console Syntax
tutorial_1003_a=\ Settings of the H2 Console
tutorial_1004_a=\ Connecting to a Database using JDBC
tutorial_1005_a=\ Creating New Databases
tutorial_1006_a=\ Using the Server
tutorial_1007_a=\ Using Hibernate
tutorial_1008_a=\ Using TopLink and Glassfish
tutorial_1009_a=\ Using EclipseLink
tutorial_1010_a=\ Using Apache ActiveMQ
tutorial_1011_a=\ Using H2 within NetBeans
tutorial_1012_a=\ Using H2 with jOOQ
tutorial_1013_a=\ Using Databases in Web Applications
tutorial_1014_a=\ Android
tutorial_1015_a=\ CSV (Comma Separated Values) Support
tutorial_1016_a=\ Upgrade, Backup, and Restore
tutorial_1017_a=\ Command Line Tools
tutorial_1018_a=\ The Shell Tool
tutorial_1019_a=\ Using OpenOffice Base
tutorial_1020_a=\ Java Web Start / JNLP
tutorial_1021_a=\ Using a Connection Pool
tutorial_1022_a=\ Fulltext Search
tutorial_1023_a=\ User-Defined Variables
tutorial_1024_a=\ Date and Time
tutorial_1025_a=\ Using Spring
tutorial_1026_a=\ OSGi
tutorial_1027_a=\ Java Management Extension (JMX)
tutorial_1028_h2=Starting and Using the H2 Console
tutorial_1029_p=\ The H2 Console application lets you access a database using a browser. This can be a H2 database, or another database that supports the JDBC API. 
tutorial_1030_p=\ This is a client/server application, so both a server and a client (a browser) are required to run it. 
tutorial_1031_p=\ Depending on your platform and environment, there are multiple ways to start the H2 Console\: 
tutorial_1032_th=OS
tutorial_1033_th=Start
tutorial_1034_td=Windows
tutorial_1035_td=\ Click [Start], [All Programs], [H2], and [H2 Console (Command Line)]
tutorial_1036_td=\ An icon will be added to the system tray\: 
tutorial_1037_td=\ If you don't get the window and the system tray icon, then maybe Java is not installed correctly (in this case, try another way to start the application). A browser window should open and point to the login page at <code>http\://localhost\:8082</code>. 
tutorial_1038_td=Windows
tutorial_1039_td=\ Open a file browser, navigate to <code>h2/bin</code>, and double click on <code>h2.bat</code>.
tutorial_1040_td=\ A console window appears. If there is a problem, you will see an error message in this window. A browser window will open and point to the login page (URL\: <code>http\://localhost\:8082</code>). 
tutorial_1041_td=Any
tutorial_1042_td=\ Double click on the <code>h2*.jar</code> file. This only works if the <code>.jar</code> suffix is associated with Java. 
tutorial_1043_td=Any
tutorial_1044_td=\ Open a console window, navigate to the directory <code>h2/bin</code>, and type\: 
tutorial_1045_h3=Firewall
tutorial_1046_p=\ If you start the server, you may get a security warning from the firewall (if you have installed one). If you don't want other computers in the network to access the application on your machine, you can let the firewall block those connections. The connection from the local machine will still work. Only if you want other computers to access the database on this computer, you need allow remote connections in the firewall. 
tutorial_1047_p=\ It has been reported that when using Kaspersky 7.0 with firewall, the H2 Console is very slow when connecting over the IP address. A workaround is to connect using 'localhost'. 
tutorial_1048_p=\ A small firewall is already built into the server\: other computers may not connect to the server by default. To change this, go to 'Preferences' and select 'Allow connections from other computers'. 
tutorial_1049_h3=Testing Java
tutorial_1050_p=\ To find out which version of Java is installed, open a command prompt and type\: 
tutorial_1051_p=\ If you get an error message, you may need to add the Java binary directory to the path environment variable. 
tutorial_1052_h3=Error Message 'Port may be in use'
tutorial_1053_p=\ You can only start one instance of the H2 Console, otherwise you will get the following error message\: "The Web server could not be started. Possible cause\: another server is already running...". It is possible to start multiple console applications on the same computer (using different ports), but this is usually not required as the console supports multiple concurrent connections. 
tutorial_1054_h3=Using another Port
tutorial_1055_p=\ If the default port of the H2 Console is already in use by another application, then a different port needs to be configured. The settings are stored in a properties file. For details, see <a href\="\#console_settings">Settings of the H2 Console</a>. The relevant entry is <code>webPort</code>. 
tutorial_1056_p=\ If no port is specified for the TCP and PG servers, each service will try to listen on its default port. If the default port is already in use, a random port is used. 
tutorial_1057_h3=Connecting to the Server using a Browser
tutorial_1058_p=\ If the server started successfully, you can connect to it using a web browser. Javascript needs to be enabled. If you started the server on the same computer as the browser, open the URL <code>http\://localhost\:8082</code>. If you want to connect to the application from another computer, you need to provide the IP address of the server, for example\: <code>http\://192.168.0.2\:8082</code>. If you enabled SSL on the server side, the URL needs to start with <code>https\://</code>. 
tutorial_1059_h3=Multiple Concurrent Sessions
tutorial_1060_p=\ Multiple concurrent browser sessions are supported. As that the database objects reside on the server, the amount of concurrent work is limited by the memory available to the server application. 
tutorial_1061_h3=Login
tutorial_1062_p=\ At the login page, you need to provide connection information to connect to a database. Set the JDBC driver class of your database, the JDBC URL, user name, and password. If you are done, click [Connect]. 
tutorial_1063_p=\ You can save and reuse previously saved settings. The settings are stored in a properties file (see <a href\="\#console_settings">Settings of the H2 Console</a>). 
tutorial_1064_h3=Error Messages
tutorial_1065_p=\ Error messages in are shown in red. You can show/hide the stack trace of the exception by clicking on the message. 
tutorial_1066_h3=Adding Database Drivers
tutorial_1067_p=\ To register additional JDBC drivers (MySQL, PostgreSQL, HSQLDB,...), add the jar file names to the environment variables <code>H2DRIVERS</code> or <code>CLASSPATH</code>. Example (Windows)\: to add the HSQLDB JDBC driver <code>C\:\\Programs\\hsqldb\\lib\\hsqldb.jar</code>, set the environment variable <code>H2DRIVERS</code> to <code>C\:\\Programs\\hsqldb\\lib\\hsqldb.jar</code>. 
tutorial_1068_p=\ Multiple drivers can be set; entries need to be separated by <code>;</code> (Windows) or <code>\:</code> (other operating systems). Spaces in the path names are supported. The settings must not be quoted. 
tutorial_1069_h3=Using the H2 Console
tutorial_1070_p=\ The H2 Console application has three main panels\: the toolbar on top, the tree on the left, and the query/result panel on the right. The database objects (for example, tables) are listed on the left. Type a SQL command in the query panel and click [Run]. The result appears just below the command. 
tutorial_1071_h3=Inserting Table Names or Column Names
tutorial_1072_p=\ To insert table and column names into the script, click on the item in the tree. If you click on a table while the query is empty, then <code>SELECT * FROM ...</code> is added. While typing a query, the table that was used is expanded in the tree. For example if you type <code>SELECT * FROM TEST T WHERE T.</code> then the table TEST is expanded. 
tutorial_1073_h3=Disconnecting and Stopping the Application
tutorial_1074_p=\ To log out of the database, click [Disconnect] in the toolbar panel. However, the server is still running and ready to accept new sessions. 
tutorial_1075_p=\ To stop the server, right click on the system tray icon and select [Exit]. If you don't have the system tray icon, navigate to [Preferences] and click [Shutdown], press [Ctrl]+[C] in the console where the server was started (Windows), or close the console window. 
tutorial_1076_h2=Special H2 Console Syntax
tutorial_1077_p=\ The H2 Console supports a few built-in commands. Those are interpreted within the H2 Console, so they work with any database. Built-in commands need to be at the beginning of a statement (before any remarks), otherwise they are not parsed correctly. If in doubt, add <code>;</code> before the command. 
tutorial_1078_th=Command(s)
tutorial_1079_th=Description
tutorial_1080_td=\ @autocommit_true;
tutorial_1081_td=\ @autocommit_false; 
tutorial_1082_td=\ Enable or disable autocommit. 
tutorial_1083_td=\ @cancel; 
tutorial_1084_td=\ Cancel the currently running statement. 
tutorial_1085_td=\ @columns null null TEST;
tutorial_1086_td=\ @index_info&nbsp;null&nbsp;null&nbsp;TEST;
tutorial_1087_td=\ @tables;
tutorial_1088_td=\ @tables null null TEST;
tutorial_1089_td=\ Call the corresponding <code>DatabaseMetaData.get</code> method. Patterns are case sensitive (usually identifiers are uppercase). For information about the parameters, see the Javadoc documentation. Missing parameters at the end of the line are set to null. The complete list of metadata commands is\: <code> @attributes, @best_row_identifier, @catalogs, @columns, @column_privileges, @cross_references, @exported_keys, @imported_keys, @index_info, @primary_keys, @procedures, @procedure_columns, @schemas, @super_tables, @super_types, @tables, @table_privileges, @table_types, @type_info, @udts, @version_columns </code> 
tutorial_1090_td=\ @edit select * from test; 
tutorial_1091_td=\ Use an updatable result set. 
tutorial_1092_td=\ @generated&nbsp;insert&nbsp;into&nbsp;test()&nbsp;values(); 
tutorial_1093_td=\ Show the result of <code>Statement.getGeneratedKeys()</code>. 
tutorial_1094_td=\ @history; 
tutorial_1095_td=\ List the command history. 
tutorial_1096_td=\ @info; 
tutorial_1097_td=\ Display the result of various <code>Connection</code> and <code>DatabaseMetaData</code> methods. 
tutorial_1098_td=\ @list select * from test; 
tutorial_1099_td=\ Show the result set in list format (each column on its own line, with row numbers). 
tutorial_1100_td=\ @loop 1000 select ?, ?/*rnd*/;
tutorial_1101_td=\ @loop 1000 @statement select ?; 
tutorial_1102_td=\ Run the statement this many times. Parameters (<code>?</code>) are set using a loop from 0 up to x - 1. Random values are used for each <code>?/*rnd*/</code>. A Statement object is used instead of a PreparedStatement if <code>@statement</code> is used. Result sets are read until <code>ResultSet.next()</code> returns <code>false</code>. Timing information is printed. 
tutorial_1103_td=\ @maxrows&nbsp;20; 
tutorial_1104_td=\ Set the maximum number of rows to display. 
tutorial_1105_td=\ @memory; 
tutorial_1106_td=\ Show the used and free memory. This will call <code>System.gc()</code>. 
tutorial_1107_td=\ @meta&nbsp;select&nbsp;1; 
tutorial_1108_td=\ List the <code>ResultSetMetaData</code> after running the query. 
tutorial_1109_td=\ @parameter_meta&nbsp;select&nbsp;?; 
tutorial_1110_td=\ Show the result of the <code>PreparedStatement.getParameterMetaData()</code> calls. The statement is not executed. 
tutorial_1111_td=\ @prof_start;
tutorial_1112_td=\ call&nbsp;hash('SHA256',&nbsp;'',&nbsp;1000000);
tutorial_1113_td=\ @prof_stop; 
tutorial_1114_td=\ Start/stop the built-in profiling tool. The top 3 stack traces of the statement(s) between start and stop are listed (if there are 3). 
tutorial_1115_td=\ @prof_start;
tutorial_1116_td=\ @sleep 10;
tutorial_1117_td=\ @prof_stop; 
tutorial_1118_td=\ Sleep for a number of seconds. Used to profile a long running query or operation that is running in another session (but in the same process). 
tutorial_1119_td=\ @transaction_isolation;
tutorial_1120_td=\ @transaction_isolation&nbsp;2; 
tutorial_1121_td=\ Display (without parameters) or change (with parameters 1, 2, 4, 8) the transaction isolation level. 
tutorial_1122_h2=Settings of the H2 Console
tutorial_1123_p=\ The settings of the H2 Console are stored in a configuration file called <code>.h2.server.properties</code> in you user home directory. For Windows installations, the user home directory is usually <code>C\:\\Documents and Settings\\[username]</code> or <code>C\:\\Users\\[username]</code>. The configuration file contains the settings of the application and is automatically created when the H2 Console is first started. Supported settings are\: 
tutorial_1124_code=webAllowOthers
tutorial_1125_li=\: allow other computers to connect. 
tutorial_1126_code=webPort
tutorial_1127_li=\: the port of the H2 Console 
tutorial_1128_code=webSSL
tutorial_1129_li=\: use encrypted (HTTPS) connections. 
tutorial_1130_p=\ In addition to those settings, the properties of the last recently used connection are listed in the form <code>&lt;number&gt;\=&lt;name&gt;|&lt;driver&gt;|&lt;url&gt;|&lt;user&gt;</code> using the escape character <code>\\</code>. Example\: <code>1\=Generic H2 (Embedded)|org.h2.Driver|jdbc\\\:h2\\\:~/test|sa</code> 
tutorial_1131_h2=Connecting to a Database using JDBC
tutorial_1132_p=\ To connect to a database, a Java application first needs to load the database driver, and then get a connection. A simple way to do that is using the following code\: 
tutorial_1133_p=\ This code first loads the driver (<code>Class.forName(...)</code>) and then opens a connection (using <code>DriverManager.getConnection()</code>). The driver name is <code>"org.h2.Driver"</code>. The database URL always needs to start with <code>jdbc\:h2\:</code> to be recognized by this database. The second parameter in the <code>getConnection()</code> call is the user name (<code>sa</code> for System Administrator in this example). The third parameter is the password. In this database, user names are not case sensitive, but passwords are. 
tutorial_1134_h2=Creating New Databases
tutorial_1135_p=\ By default, if the database specified in the URL does not yet exist, a new (empty) database is created automatically. The user that created the database automatically becomes the administrator of this database. 
tutorial_1136_p=\ Auto-creating new database can be disabled, see <a href\="features.html\#database_only_if_exists">Opening a Database Only if it Already Exists</a>. 
tutorial_1137_h2=Using the Server
tutorial_1138_p=\ H2 currently supports three server\: a web server (for the H2 Console), a TCP server (for client/server connections) and an PG server (for PostgreSQL clients). Please note that only the web server supports browser connections. The servers can be started in different ways, one is using the <code>Server</code> tool. Starting the server doesn't open a database - databases are opened as soon as a client connects. 
tutorial_1139_h3=Starting the Server Tool from Command Line
tutorial_1140_p=\ To start the <code>Server</code> tool from the command line with the default settings, run\: 
tutorial_1141_p=\ This will start the tool with the default options. To get the list of options and default values, run\: 
tutorial_1142_p=\ There are options available to use other ports, and start or not start parts. 
tutorial_1143_h3=Connecting to the TCP Server
tutorial_1144_p=\ To remotely connect to a database using the TCP server, use the following driver and database URL\: 
tutorial_1145_li=JDBC driver class\: <code>org.h2.Driver</code> 
tutorial_1146_li=Database URL\: <code>jdbc\:h2\:tcp\://localhost/~/test</code> 
tutorial_1147_p=\ For details about the database URL, see also in Features. Please note that you can't connection with a web browser to this URL. You can only connect using a H2 client (over JDBC). 
tutorial_1148_h3=Starting the TCP Server within an Application
tutorial_1149_p=\ Servers can also be started and stopped from within an application. Sample code\: 
tutorial_1150_h3=Stopping a TCP Server from Another Process
tutorial_1151_p=\ The TCP server can be stopped from another process. To stop the server from the command line, run\: 
tutorial_1152_p=\ To stop the server from a user application, use the following code\: 
tutorial_1153_p=\ This function will only stop the TCP server. If other server were started in the same process, they will continue to run. To avoid recovery when the databases are opened the next time, all connections to the databases should be closed before calling this method. To stop a remote server, remote connections must be enabled on the server. Shutting down a TCP server can be protected using the option <code>-tcpPassword</code> (the same password must be used to start and stop the TCP server). 
tutorial_1154_h2=Using Hibernate
tutorial_1155_p=\ This database supports Hibernate version 3.1 and newer. You can use the HSQLDB Dialect, or the native H2 Dialect. Unfortunately the H2 Dialect included in some old versions of Hibernate was buggy. A <a href\="http\://opensource.atlassian.com/projects/hibernate/browse/HHH-3401">patch for Hibernate</a> has been submitted and is now applied. You can rename it to <code>H2Dialect.java</code> and include this as a patch in your application, or upgrade to a version of Hibernate where this is fixed. 
tutorial_1156_p=\ When using Hibernate, try to use the <code>H2Dialect</code> if possible. When using the <code>H2Dialect</code>, compatibility modes such as <code>MODE\=MySQL</code> are not supported. When using such a compatibility mode, use the Hibernate dialect for the corresponding database instead of the <code>H2Dialect</code>; but please note H2 does not support all features of all databases. 
tutorial_1157_h2=Using TopLink and Glassfish
tutorial_1158_p=\ To use H2 with Glassfish (or Sun AS), set the Datasource Classname to <code>org.h2.jdbcx.JdbcDataSource</code>. You can set this in the GUI at Application Server - Resources - JDBC - Connection Pools, or by editing the file <code>sun-resources.xml</code>\: at element <code>jdbc-connection-pool</code>, set the attribute <code>datasource-classname</code> to <code>org.h2.jdbcx.JdbcDataSource</code>. 
tutorial_1159_p=\ The H2 database is compatible with HSQLDB and PostgreSQL. To take advantage of H2 specific features, use the <code>H2Platform</code>. The source code of this platform is included in H2 at <code>src/tools/oracle/toplink/essentials/platform/database/DatabasePlatform.java.txt</code>. You will need to copy this file to your application, and rename it to .java. To enable it, change the following setting in persistence.xml\: 
tutorial_1160_p=\ In old versions of Glassfish, the property name is <code>toplink.platform.class.name</code>. 
tutorial_1161_p=\ To use H2 within Glassfish, copy the h2*.jar to the directory <code>glassfish/glassfish/lib</code>. 
tutorial_1162_h2=Using EclipseLink
tutorial_1163_p=\ To use H2 in EclipseLink, use the platform class <code>org.eclipse.persistence.platform.database.H2Platform</code>. If this platform is not available in your version of EclipseLink, you can use the OraclePlatform instead in many case. See also <a href\="http\://wiki.eclipse.org/EclipseLink/Development/Incubator/Extensions/H2Platform">H2Platform</a>. 
tutorial_1164_h2=Using Apache ActiveMQ
tutorial_1165_p=\ When using H2 as the backend database for Apache ActiveMQ, please use the <code>TransactDatabaseLocker</code> instead of the default locking mechanism. Otherwise the database file will grow without bounds. The problem is that the default locking mechanism uses an uncommitted <code>UPDATE</code> transaction, which keeps the transaction log from shrinking (causes the database file to grow). Instead of using an <code>UPDATE</code> statement, the <code>TransactDatabaseLocker</code> uses <code>SELECT ... FOR UPDATE</code> which is not problematic. To use it, change the ApacheMQ configuration element <code>&lt;jdbcPersistenceAdapter&gt;</code> element, property <code>databaseLocker\="org.apache.activemq.store.jdbc.adapter.TransactDatabaseLocker"</code>. However, using the MVCC mode will again result in the same problem. Therefore, please do not use the MVCC mode in this case. Another (more dangerous) solution is to set <code>useDatabaseLock</code> to false. 
tutorial_1166_h2=Using H2 within NetBeans
tutorial_1167_p=\ The project <a href\="http\://kenai.com/projects/nbh2">H2 Database Engine Support For NetBeans</a> allows you to start and stop the H2 server from within the IDE. 
tutorial_1168_p=\ There is a known issue when using the Netbeans SQL Execution Window\: before executing a query, another query in the form <code>SELECT COUNT(*) FROM &lt;query&gt;</code> is run. This is a problem for queries that modify state, such as <code>SELECT SEQ.NEXTVAL</code>. In this case, two sequence values are allocated instead of just one. 
tutorial_1169_h2=Using H2 with jOOQ
tutorial_1170_p=\ jOOQ adds a thin layer on top of JDBC, allowing for type-safe SQL construction, including advanced SQL, stored procedures and advanced data types. jOOQ takes your database schema as a base for code generation. If this is your example schema\: 
tutorial_1171_p=\ then run the jOOQ code generator on the command line using this command\: 
tutorial_1172_p=\ ...where <code>codegen.xml</code> is on the classpath and contains this information 
tutorial_1173_p=\ Using the generated source, you can query the database as follows\: 
tutorial_1174_p=\ See more details on <a href\="http\://www.jooq.org">jOOQ Homepage</a> and in the <a href\="http\://www.jooq.org/tutorial.php">jOOQ Tutorial</a> 
tutorial_1175_h2=Using Databases in Web Applications
tutorial_1176_p=\ There are multiple ways to access a database from within web applications. Here are some examples if you use Tomcat or JBoss. 
tutorial_1177_h3=Embedded Mode
tutorial_1178_p=\ The (currently) simplest solution is to use the database in the embedded mode, that means open a connection in your application when it starts (a good solution is using a Servlet Listener, see below), or when a session starts. A database can be accessed from multiple sessions and applications at the same time, as long as they run in the same process. Most Servlet Containers (for example Tomcat) are just using one process, so this is not a problem (unless you run Tomcat in clustered mode). Tomcat uses multiple threads and multiple classloaders. If multiple applications access the same database at the same time, you need to put the database jar in the <code>shared/lib</code> or <code>server/lib</code> directory. It is a good idea to open the database when the web application starts, and close it when the web application stops. If using multiple applications, only one (any) of them needs to do that. In the application, an idea is to use one connection per Session, or even one connection per request (action). Those connections should be closed after use if possible (but it's not that bad if they don't get closed). 
tutorial_1179_h3=Server Mode
tutorial_1180_p=\ The server mode is similar, but it allows you to run the server in another process. 
tutorial_1181_h3=Using a Servlet Listener to Start and Stop a Database
tutorial_1182_p=\ Add the h2*.jar file to your web application, and add the following snippet to your web.xml file (between the <code>context-param</code> and the <code>filter</code> section)\: 
tutorial_1183_p=\ For details on how to access the database, see the file <code>DbStarter.java</code>. By default this tool opens an embedded connection using the database URL <code>jdbc\:h2\:~/test</code>, user name <code>sa</code>, and password <code>sa</code>. If you want to use this connection within your servlet, you can access as follows\: 
tutorial_1184_code=DbStarter
tutorial_1185_p=\ can also start the TCP server, however this is disabled by default. To enable it, use the parameter <code>db.tcpServer</code> in the file <code>web.xml</code>. Here is the complete list of options. These options need to be placed between the <code>description</code> tag and the <code>listener</code> / <code>filter</code> tags\: 
tutorial_1186_p=\ When the web application is stopped, the database connection will be closed automatically. If the TCP server is started within the <code>DbStarter</code>, it will also be stopped automatically. 
tutorial_1187_h3=Using the H2 Console Servlet
tutorial_1188_p=\ The H2 Console is a standalone application and includes its own web server, but it can be used as a servlet as well. To do that, include the the <code>h2*.jar</code> file in your application, and add the following configuration to your <code>web.xml</code>\: 
tutorial_1189_p=\ For details, see also <code>src/tools/WEB-INF/web.xml</code>. 
tutorial_1190_p=\ To create a web application with just the H2 Console, run the following command\: 
tutorial_1191_h2=Android
tutorial_1192_p=\ You can use this database on an Android device (using the Dalvik VM) instead of or in addition to SQLite. So far, only very few tests and benchmarks were run, but it seems that performance is similar to SQLite, except for opening and closing a database, which is not yet optimized in H2 (H2 takes about 0.2 seconds, and SQLite about 0.02 seconds). Read operations seem to be a bit faster than SQLite, and write operations seem to be slower. So far, only very few tests have been run, and everything seems to work as expected. Fulltext search was not yet tested, however the native fulltext search should work. 
tutorial_1193_p=\ Reasons to use H2 instead of SQLite are\: 
tutorial_1194_li=Full Unicode support including UPPER() and LOWER(). 
tutorial_1195_li=Streaming API for BLOB and CLOB data. 
tutorial_1196_li=Fulltext search. 
tutorial_1197_li=Multiple connections. 
tutorial_1198_li=User defined functions and triggers. 
tutorial_1199_li=Database file encryption. 
tutorial_1200_li=Reading and writing CSV files (this feature can be used outside the database as well). 
tutorial_1201_li=Referential integrity and check constraints. 
tutorial_1202_li=Better data type and SQL support. 
tutorial_1203_li=In-memory databases, read-only databases, linked tables. 
tutorial_1204_li=Better compatibility with other databases which simplifies porting applications. 
tutorial_1205_li=Possibly better performance (so far for read operations). 
tutorial_1206_li=Server mode (accessing a database on a different machine over TCP/IP). 
tutorial_1207_p=\ Currently only the JDBC API is supported (it is planned to support the Android database API in future releases). Both the regular H2 jar file and the smaller <code>h2small-*.jar</code> can be used. To create the smaller jar file, run the command <code>./build.sh jarSmall</code> (Linux / Mac OS) or <code>build.bat jarSmall</code> (Windows). 
tutorial_1208_p=\ The database files needs to be stored in a place that is accessible for the application. Example\: 
tutorial_1209_p=\ Limitations\: Using a connection pool is currently not supported, because the required <code>javax.sql.</code> classes are not available on Android. 
tutorial_1210_h2=CSV (Comma Separated Values) Support
tutorial_1211_p=\ The CSV file support can be used inside the database using the functions <code>CSVREAD</code> and <code>CSVWRITE</code>, or it can be used outside the database as a standalone tool. 
tutorial_1212_h3=Reading a CSV File from Within a Database
tutorial_1213_p=\ A CSV file can be read using the function <code>CSVREAD</code>. Example\: 
tutorial_1214_p=\ Please note for performance reason, <code>CSVREAD</code> should not be used inside a join. Instead, import the data first (possibly into a temporary table), create the required indexes if necessary, and then query this table. 
tutorial_1215_h3=Importing Data from a CSV File
tutorial_1216_p=\ A fast way to load or import data (sometimes called 'bulk load') from a CSV file is to combine table creation with import. Optionally, the column names and data types can be set when creating the table. Another option is to use <code>INSERT INTO ... SELECT</code>. 
tutorial_1217_h3=Writing a CSV File from Within a Database
tutorial_1218_p=\ The built-in function <code>CSVWRITE</code> can be used to create a CSV file from a query. Example\: 
tutorial_1219_h3=Writing a CSV File from a Java Application
tutorial_1220_p=\ The <code>Csv</code> tool can be used in a Java application even when not using a database at all. Example\: 
tutorial_1221_h3=Reading a CSV File from a Java Application
tutorial_1222_p=\ It is possible to read a CSV file without opening a database. Example\: 
tutorial_1223_h2=Upgrade, Backup, and Restore
tutorial_1224_h3=Database Upgrade
tutorial_1225_p=\ The recommended way to upgrade from one version of the database engine to the next version is to create a backup of the database (in the form of a SQL script) using the old engine, and then execute the SQL script using the new engine. 
tutorial_1226_h3=Backup using the Script Tool
tutorial_1227_p=\ The recommended way to backup a database is to create a compressed SQL script file. This will result in a small, human readable, and database version independent backup. Creating the script will also verify the checksums of the database file. The <code>Script</code> tool is ran as follows\: 
tutorial_1228_p=\ It is also possible to use the SQL command <code>SCRIPT</code> to create the backup of the database. For more information about the options, see the SQL command <code>SCRIPT</code>. The backup can be done remotely, however the file will be created on the server side. The built in FTP server could be used to retrieve the file from the server. 
tutorial_1229_h3=Restore from a Script
tutorial_1230_p=\ To restore a database from a SQL script file, you can use the <code>RunScript</code> tool\: 
tutorial_1231_p=\ For more information about the options, see the SQL command <code>RUNSCRIPT</code>. The restore can be done remotely, however the file needs to be on the server side. The built in FTP server could be used to copy the file to the server. It is also possible to use the SQL command <code>RUNSCRIPT</code> to execute a SQL script. SQL script files may contain references to other script files, in the form of <code>RUNSCRIPT</code> commands. However, when using the server mode, the references script files need to be available on the server side. 
tutorial_1232_h3=Online Backup
tutorial_1233_p=\ The <code>BACKUP</code> SQL statement and the <code>Backup</code> tool both create a zip file with the database file. However, the contents of this file are not human readable. 
tutorial_1234_p=\ The resulting backup is transactionally consistent, meaning the consistency and atomicity rules apply. 
tutorial_1235_p=\ The <code>Backup</code> tool (<code>org.h2.tools.Backup</code>) can not be used to create a online backup; the database must not be in use while running this program. 
tutorial_1236_p=\ Creating a backup by copying the database files while the database is running is not supported, except if the file systems support creating snapshots. With other file systems, it can't be guaranteed that the data is copied in the right order. 
tutorial_1237_h2=Command Line Tools
tutorial_1238_p=\ This database comes with a number of command line tools. To get more information about a tool, start it with the parameter '-?', for example\: 
tutorial_1239_p=\ The command line tools are\: 
tutorial_1240_code=Backup
tutorial_1241_li=\ creates a backup of a database. 
tutorial_1242_code=ChangeFileEncryption
tutorial_1243_li=\ allows changing the file encryption password or algorithm of a database. 
tutorial_1244_code=Console
tutorial_1245_li=\ starts the browser based H2 Console. 
tutorial_1246_code=ConvertTraceFile
tutorial_1247_li=\ converts a .trace.db file to a Java application and SQL script. 
tutorial_1248_code=CreateCluster
tutorial_1249_li=\ creates a cluster from a standalone database. 
tutorial_1250_code=DeleteDbFiles
tutorial_1251_li=\ deletes all files belonging to a database. 
tutorial_1252_code=Recover
tutorial_1253_li=\ helps recovering a corrupted database. 
tutorial_1254_code=Restore
tutorial_1255_li=\ restores a backup of a database. 
tutorial_1256_code=RunScript
tutorial_1257_li=\ runs a SQL script against a database. 
tutorial_1258_code=Script
tutorial_1259_li=\ allows converting a database to a SQL script for backup or migration. 
tutorial_1260_code=Server
tutorial_1261_li=\ is used in the server mode to start a H2 server. 
tutorial_1262_code=Shell
tutorial_1263_li=\ is a command line database tool. 
tutorial_1264_p=\ The tools can also be called from an application by calling the main or another public method. For details, see the Javadoc documentation. 
tutorial_1265_h2=The Shell Tool
tutorial_1266_p=\ The Shell tool is a simple interactive command line tool. To start it, type\: 
tutorial_1267_p=\ You will be asked for a database URL, JDBC driver, user name, and password. The connection setting can also be set as command line parameters. After connecting, you will get the list of options. The built-in commands don't need to end with a semicolon, but SQL statements are only executed if the line ends with a semicolon <code>;</code>. This allows to enter multi-line statements\: 
tutorial_1268_p=\ By default, results are printed as a table. For results with many column, consider using the list mode\: 
tutorial_1269_h2=Using OpenOffice Base
tutorial_1270_p=\ OpenOffice.org Base supports database access over the JDBC API. To connect to a H2 database using OpenOffice Base, you first need to add the JDBC driver to OpenOffice. The steps to connect to a H2 database are\: 
tutorial_1271_li=Start OpenOffice Writer, go to [Tools], [Options] 
tutorial_1272_li=Make sure you have selected a Java runtime environment in OpenOffice.org / Java 
tutorial_1273_li=Click [Class Path...], [Add Archive...] 
tutorial_1274_li=Select your h2 jar file (location is up to you, could be wherever you choose) 
tutorial_1275_li=Click [OK] (as much as needed), stop OpenOffice (including the Quickstarter) 
tutorial_1276_li=Start OpenOffice Base 
tutorial_1277_li=Connect to an existing database; select [JDBC]; [Next] 
tutorial_1278_li=Example datasource URL\: <code>jdbc\:h2\:~/test</code> 
tutorial_1279_li=JDBC driver class\: <code>org.h2.Driver</code> 
tutorial_1280_p=\ Now you can access the database stored in the current users home directory. 
tutorial_1281_p=\ To use H2 in NeoOffice (OpenOffice without X11)\: 
tutorial_1282_li=In NeoOffice, go to [NeoOffice], [Preferences] 
tutorial_1283_li=Look for the page under [NeoOffice], [Java] 
tutorial_1284_li=Click [Class Path], [Add Archive...] 
tutorial_1285_li=Select your h2 jar file (location is up to you, could be wherever you choose) 
tutorial_1286_li=Click [OK] (as much as needed), restart NeoOffice. 
tutorial_1287_p=\ Now, when creating a new database using the "Database Wizard" \: 
tutorial_1288_li=Click [File], [New], [Database]. 
tutorial_1289_li=Select [Connect to existing database] and the select [JDBC]. Click next. 
tutorial_1290_li=Example datasource URL\: <code>jdbc\:h2\:~/test</code> 
tutorial_1291_li=JDBC driver class\: <code>org.h2.Driver</code> 
tutorial_1292_p=\ Another solution to use H2 in NeoOffice is\: 
tutorial_1293_li=Package the h2 jar within an extension package 
tutorial_1294_li=Install it as a Java extension in NeoOffice 
tutorial_1295_p=\ This can be done by create it using the NetBeans OpenOffice plugin. See also <a href\="http\://wiki.services.openoffice.org/wiki/Extensions_development_java">Extensions Development</a>. 
tutorial_1296_h2=Java Web Start / JNLP
tutorial_1297_p=\ When using Java Web Start / JNLP (Java Network Launch Protocol), permissions tags must be set in the .jnlp file, and the application .jar file must be signed. Otherwise, when trying to write to the file system, the following exception will occur\: <code>java.security.AccessControlException</code>\: access denied (<code>java.io.FilePermission ... read</code>). Example permission tags\: 
tutorial_1298_h2=Using a Connection Pool
tutorial_1299_p=\ For H2, opening a connection is fast if the database is already open. Still, using a connection pool improves performance if you open and close connections a lot. A simple connection pool is included in H2. It is based on the <a href\="http\://www.source-code.biz/snippets/java/8.htm">Mini Connection Pool Manager</a> from Christian d'Heureuse. There are other, more complex, open source connection pools available, for example the <a href\="http\://jakarta.apache.org/commons/dbcp/">Apache Commons DBCP</a>. For H2, it is about twice as faster to get a connection from the built-in connection pool than to get one using <code>DriverManager.getConnection()</code>.The build-in connection pool is used as follows\: 
tutorial_1300_h2=Fulltext Search
tutorial_1301_p=\ H2 includes two fulltext search implementations. One is using Apache Lucene, and the other (the native implementation) stores the index data in special tables in the database. 
tutorial_1302_h3=Using the Native Fulltext Search
tutorial_1303_p=\ To initialize, call\: 
tutorial_1304_p=\ You need to initialize it in each database where you want to use it. Afterwards, you can create a fulltext index for a table using\: 
tutorial_1305_p=\ PUBLIC is the schema name, TEST is the table name. The list of column names (comma separated) is optional, in this case all columns are indexed. The index is updated in realtime. To search the index, use the following query\: 
tutorial_1306_p=\ This will produce a result set that contains the query needed to retrieve the data\: 
tutorial_1307_p=\ To drop an index on a table\: 
tutorial_1308_p=\ To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in\: <code>SELECT T.* FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE\='TEST' AND T.ID\=FT.KEYS[0];</code> 
tutorial_1309_p=\ You can also call the index from within a Java application\: 
tutorial_1310_h3=Using the Lucene Fulltext Search
tutorial_1311_p=\ To use the Lucene full text search, you need the Lucene library in the classpath. Currently Apache Lucene version 2.x is used by default for H2 version 1.2.x, and Lucene version 3.x is used by default for H2 version 1.3.x. How to do that depends on the application; if you use the H2 Console, you can add the Lucene jar file to the environment variables <code>H2DRIVERS</code> or <code>CLASSPATH</code>. To initialize the Lucene fulltext search in a database, call\: 
tutorial_1312_p=\ You need to initialize it in each database where you want to use it. Afterwards, you can create a full text index for a table using\: 
tutorial_1313_p=\ PUBLIC is the schema name, TEST is the table name. The list of column names (comma separated) is optional, in this case all columns are indexed. The index is updated in realtime. To search the index, use the following query\: 
tutorial_1314_p=\ This will produce a result set that contains the query needed to retrieve the data\: 
tutorial_1315_p=\ To drop an index on a table (be warned that this will re-index all of the full-text indices for the entire database)\: 
tutorial_1316_p=\ To get the raw data, use <code>FTL_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in\: <code>SELECT T.* FROM FTL_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE\='TEST' AND T.ID\=FT.KEYS[0];</code> 
tutorial_1317_p=\ You can also call the index from within a Java application\: 
tutorial_1318_p=\ The Lucene fulltext search supports searching in specific column only. Column names must be uppercase (except if the original columns are double quoted). For column names starting with an underscore (_), another underscore needs to be added. Example\: 
tutorial_1319_p=\ The Lucene fulltext search implementation is not synchronized internally. If you update the database and query the fulltext search concurrently (directly using the Java API of H2 or Lucene itself), you need to ensure operations are properly synchronized. If this is not the case, you may get exceptions such as <code>org.apache.lucene.store.AlreadyClosedException\: this IndexReader is closed</code>. 
tutorial_1320_h2=User-Defined Variables
tutorial_1321_p=\ This database supports user-defined variables. Variables start with <code>@</code> and can be used wherever expressions or parameters are allowed. Variables are not persisted and session scoped, that means only visible from within the session in which they are defined. A value is usually assigned using the SET command\: 
tutorial_1322_p=\ The value can also be changed using the SET() method. This is useful in queries\: 
tutorial_1323_p=\ Variables that are not set evaluate to <code>NULL</code>. The data type of a user-defined variable is the data type of the value assigned to it, that means it is not necessary (or possible) to declare variable names before using them. There are no restrictions on the assigned values; large objects (LOBs) are supported as well. Rolling back a transaction does not affect the value of a user-defined variable. 
tutorial_1324_h2=Date and Time
tutorial_1325_p=\ Date, time and timestamp values support ISO 8601 formatting, including time zone\: 
tutorial_1326_p=\ If the time zone is not set, the value is parsed using the current time zone setting of the system. Date and time information is stored in H2 database files without time zone information. If the database is opened using another system time zone, the date and time will be the same. That means if you store the value '2000-01-01 12\:00\:00' in one time zone, then close the database and open the database again in a different time zone, you will also get '2000-01-01 12\:00\:00'. Please note that changing the time zone after the H2 driver is loaded is not supported. 
tutorial_1327_h2=Using Spring
tutorial_1328_h3=Using the TCP Server
tutorial_1329_p=\ Use the following configuration to start and stop the H2 TCP server using the Spring Framework\: 
tutorial_1330_p=\ The <code>destroy-method</code> will help prevent exceptions on hot-redeployment or when restarting the server. 
tutorial_1331_h3=Error Code Incompatibility
tutorial_1332_p=\ There is an incompatibility with the Spring JdbcTemplate and H2 version 1.3.154 and newer, because of a change in the error code. This will cause the JdbcTemplate to not detect a duplicate key condition, and so a <code>DataIntegrityViolationException</code> is thrown instead of <code>DuplicateKeyException</code>. See also <a href\="https\://jira.springsource.org/browse/SPR-8235">the issue SPR-8235</a>. The workaround is to add the following XML file to the root of the classpath\: 
tutorial_1333_h2=OSGi
tutorial_1334_p=\ The standard H2 jar can be dropped in as a bundle in an OSGi container. H2 implements the JDBC Service defined in OSGi Service Platform Release 4 Version 4.2 Enterprise Specification. The H2 Data Source Factory service is registered with the following properties\: <code>OSGI_JDBC_DRIVER_CLASS\=org.h2.Driver</code> and <code>OSGI_JDBC_DRIVER_NAME\=H2</code>. The <code>OSGI_JDBC_DRIVER_VERSION</code> property reflects the version of the driver as is. 
tutorial_1335_p=\ The following standard configuration properties are supported\: <code>JDBC_USER, JDBC_PASSWORD, JDBC_DESCRIPTION, JDBC_DATASOURCE_NAME, JDBC_NETWORK_PROTOCOL, JDBC_URL, JDBC_SERVER_NAME, JDBC_PORT_NUMBER</code>. Any other standard property will be rejected. Non-standard properties will be passed on to H2 in the connection URL. 
tutorial_1336_h2=Java Management Extension (JMX)
tutorial_1337_p=\ Management over JMX is supported, but not enabled by default. To enable JMX, append <code>;JMX\=TRUE</code> to the database URL when opening the database. Various tools support JMX, one such tool is the <code>jconsole</code>. When opening the <code>jconsole</code>, connect to the process where the database is open (when using the server mode, you need to connect to the server process). Then go to the <code>MBeans</code> section. Under <code>org.h2</code> you will find one entry per database. The object name of the entry is the database short name, plus the path (each colon is replaced with an underscore character). 
tutorial_1338_p=\ The following attributes and operations are supported\: 
tutorial_1339_code=CacheSize
tutorial_1340_li=\: the cache size currently in use in KB. 
tutorial_1341_code=CacheSizeMax
tutorial_1342_li=\ (read/write)\: the maximum cache size in KB. 
tutorial_1343_code=Exclusive
tutorial_1344_li=\: whether this database is open in exclusive mode or not. 
tutorial_1345_code=FileReadCount
tutorial_1346_li=\: the number of file read operations since the database was opened. 
tutorial_1347_code=FileSize
tutorial_1348_li=\: the file size in KB. 
tutorial_1349_code=FileWriteCount
tutorial_1350_li=\: the number of file write operations since the database was opened. 
tutorial_1351_code=FileWriteCountTotal
tutorial_1352_li=\: the number of file write operations since the database was created. 
tutorial_1353_code=LogMode
tutorial_1354_li=\ (read/write)\: the current transaction log mode. See <code>SET LOG</code> for details. 
tutorial_1355_code=Mode
tutorial_1356_li=\: the compatibility mode (<code>REGULAR</code> if no compatibility mode is used). 
tutorial_1357_code=MultiThreaded
tutorial_1358_li=\: true if multi-threaded is enabled. 
tutorial_1359_code=Mvcc
tutorial_1360_li=\: true if <code>MVCC</code> is enabled. 
tutorial_1361_code=ReadOnly
tutorial_1362_li=\: true if the database is read-only. 
tutorial_1363_code=TraceLevel
tutorial_1364_li=\ (read/write)\: the file trace level. 
tutorial_1365_code=Version
tutorial_1366_li=\: the database version in use. 
tutorial_1367_code=listSettings
tutorial_1368_li=\: list the database settings. 
tutorial_1369_code=listSessions
tutorial_1370_li=\: list the open sessions, including currently executing statement (if any) and locked tables (if any). 
tutorial_1371_p=\ To enable JMX, you may need to set the system properties <code>com.sun.management.jmxremote</code> and <code>com.sun.management.jmxremote.port</code> as required by the JVM.