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提交 42ed3064 authored 作者: Thomas Mueller's avatar Thomas Mueller
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h2/src/docsrc/html/advanced.html
浏览文件 @ 42ed3064
......@@ -30,6 +30,8 @@ Advanced Topics
Two Phase Commit</a><br />
<a href="#compatibility">
Compatibility</a><br />
<a href="#standards_compliance">
Standards Compliance</a><br />
<a href="#windows_service">
Run as Windows Service</a><br />
<a href="#odbc_driver">
......@@ -338,6 +340,15 @@ Certain words of this list are keywords because they are functions that can be u
for example CURRENT_TIMESTAMP.
</p>
<br /><a name="standards_compliance"></a>
<h2>Standards Compliance</h2>
<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.
</p>
<br /><a name="windows_service"></a>
<h2>Run as Windows Service</h2>
<p>
......
h2/src/docsrc/html/history.html
浏览文件 @ 42ed3064
......@@ -108,6 +108,7 @@ via PayPal:
</li><li>Elisabetta Berlini, Italy
</li><li>William Gilbert, USA
</li><li>Antonio Dieguez, Chile
</li><li><a href="http://ontologyworks.com/">Ontology Works, USA</a>
</li></ul>
</div></td></tr></table><!-- analytics --></body></html>
h2/src/docsrc/html/roadmap.html
浏览文件 @ 42ed3064
......@@ -61,6 +61,7 @@ Roadmap
</li><li>Support function overloading as in Java (multiple functions with the same name, but different parameter count or data types)
</li><li>Deferred integrity checking (DEFERRABLE INITIALLY DEFERRED)
</li><li>Groovy Stored Procedures (http://groovy.codehaus.org/Groovy+SQL)
</li><li>Linked tables that point to the same database should share the connection ([SHARED])
</li><li>System table / function: cache usage
</li><li>Add a migration guide (list differences between databases)
</li><li>Optimization: automatic index creation suggestion using the trace file?
......@@ -268,7 +269,6 @@ Roadmap
</li><li>Provide an Java SQL builder with standard and H2 syntax
</li><li>Trace: write OS, file system, JVM,... when opening the database
</li><li>Support indexes for views (probably requires materialized views)
</li><li>Linked tables that point to the same database should share the connection
</li><li>Document SET SEARCH_PATH, BEGIN, EXECUTE, parameters
</li><li>Browser: use Desktop.isDesktopSupported and browse when using JDK 1.6
</li><li>Server: use one listener (detect if the request comes from an PG or TCP client)
......
h2/src/docsrc/text/_docs_en.utf8.txt
浏览文件 @ 42ed3064
......@@ -26,876 +26,885 @@ Two Phase Commit
Compatibility
@advanced_1009_a
Run as Windows Service
Standards Compliance
@advanced_1010_a
ODBC Driver
Run as Windows Service
@advanced_1011_a
Using H2 in Microsoft .NET
ODBC Driver
@advanced_1012_a
ACID
Using H2 in Microsoft .NET
@advanced_1013_a
Durability Problems
ACID
@advanced_1014_a
Using the Recover Tool
Durability Problems
@advanced_1015_a
File Locking Protocols
Using the Recover Tool
@advanced_1016_a
Protection against SQL Injection
File Locking Protocols
@advanced_1017_a
Restricting Class Loading and Usage
Protection against SQL Injection
@advanced_1018_a
Security Protocols
Restricting Class Loading and Usage
@advanced_1019_a
Universally Unique Identifiers (UUID)
Security Protocols
@advanced_1020_a
Settings Read from System Properties
Universally Unique Identifiers (UUID)
@advanced_1021_a
Setting the Server Bind Address
Settings Read from System Properties
@advanced_1022_a
Setting the Server Bind Address
@advanced_1023_a
Glossary and Links
@advanced_1023_h2
@advanced_1024_h2
Result Sets
@advanced_1024_h3
@advanced_1025_h3
Limiting the Number of Rows
@advanced_1025_p
@advanced_1026_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 LIMIT in a query (example: SELECT * FROM TEST LIMIT 100), or by using Statement.setMaxRows(max).
@advanced_1026_h3
@advanced_1027_h3
Large Result Sets and External Sorting
@advanced_1027_p
@advanced_1028_p
For result set larger than 1000 rows, the result is buffered to disk. If ORDER BY 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_1028_h2
@advanced_1029_h2
Large Objects
@advanced_1029_h3
@advanced_1030_h3
Storing and Reading Large Objects
@advanced_1030_p
@advanced_1031_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 PreparedStatement.setBinaryStream. To store a CLOB, use PreparedStatement.setCharacterStream. To read a BLOB, use ResultSet.getBinaryStream, and to read a CLOB, use ResultSet.getCharacterStream. If the client/server mode is used, the BLOB and CLOB data is fully read into memory when accessed. In this case, the size of a BLOB or CLOB is limited by the memory.
@advanced_1031_h2
@advanced_1032_h2
Linked Tables
@advanced_1032_p
@advanced_1033_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 CREATE LINKED TABLE statement:
@advanced_1033_p
@advanced_1034_p
It is then possible to access the table in the usual way. There is a restriction when inserting data to this table: When inserting or updating rows into the table, NULL and values that are not set in the insert statement are both inserted as NULL. This may not have the desired effect if a default value in the target table is other than NULL.
@advanced_1034_p
@advanced_1035_p
For each linked table a new connection is opened. This can be a problem for some databases when using many linked tables. For Oracle XE, the maximum number of connection can be increased. Oracle XE needs to be restarted after changing these values:
@advanced_1035_h2
@advanced_1036_h2
Transaction Isolation
@advanced_1036_p
@advanced_1037_p
This database supports the following transaction isolation levels:
@advanced_1037_b
@advanced_1038_b
Read Committed
@advanced_1038_li
@advanced_1039_li
This is the default level. Read locks are released immediately. Higher concurrency is possible when using this level.
@advanced_1039_li
@advanced_1040_li
To enable, execute the SQL statement 'SET LOCK_MODE 3'
@advanced_1040_li
@advanced_1041_li
or append ;LOCK_MODE=3 to the database URL: jdbc:h2:~/test;LOCK_MODE=3
@advanced_1041_b
@advanced_1042_b
Serializable
@advanced_1042_li
@advanced_1043_li
To enable, execute the SQL statement 'SET LOCK_MODE 1'
@advanced_1043_li
@advanced_1044_li
or append ;LOCK_MODE=1 to the database URL: jdbc:h2:~/test;LOCK_MODE=1
@advanced_1044_b
@advanced_1045_b
Read Uncommitted
@advanced_1045_li
@advanced_1046_li
This level means that transaction isolation is disabled.
@advanced_1046_li
@advanced_1047_li
To enable, execute the SQL statement 'SET LOCK_MODE 0'
@advanced_1047_li
@advanced_1048_li
or append ;LOCK_MODE=0 to the database URL: jdbc:h2:~/test;LOCK_MODE=0
@advanced_1048_p
@advanced_1049_p
When using the isolation level 'serializable', dirty reads, non-repeatable reads, and phantom reads are prohibited.
@advanced_1049_b
@advanced_1050_b
Dirty Reads
@advanced_1050_li
@advanced_1051_li
Means a connection can read uncommitted changes made by another connection.
@advanced_1051_li
@advanced_1052_li
Possible with: read uncommitted
@advanced_1052_b
@advanced_1053_b
Non-Repeatable Reads
@advanced_1053_li
@advanced_1054_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_1054_li
@advanced_1055_li
Possible with: read uncommitted, read committed
@advanced_1055_b
@advanced_1056_b
Phantom Reads
@advanced_1056_li
@advanced_1057_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_1057_li
@advanced_1058_li
Possible with: read uncommitted, read committed
@advanced_1058_h3
@advanced_1059_h3
Table Level Locking
@advanced_1059_p
@advanced_1060_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.
@advanced_1060_h3
@advanced_1061_h3
Lock Timeout
@advanced_1061_p
@advanced_1062_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_1062_h2
@advanced_1063_h2
Multi-Version Concurrency Control (MVCC)
@advanced_1063_p
@advanced_1064_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 SELECT ... FOR UPDATE. 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, this database fails fast: a concurrent update exception is thrown.
@advanced_1064_p
@advanced_1065_p
To use the MVCC feature, append MVCC=TRUE to the database URL:
@advanced_1065_p
@advanced_1066_p
The MVCC feature is not fully tested yet.
@advanced_1066_h2
@advanced_1067_h2
Clustering / High Availability
@advanced_1067_p
@advanced_1068_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_1068_p
@advanced_1069_p
Clustering can only be used in the server mode (the embedded mode does not support clustering). It is possible to restore the cluster without stopping the server, however it is critical that no other application is changing the data in the first database while the second database is restored, so restoring the cluster is currently a manual process.
@advanced_1069_p
@advanced_1070_p
To initialize the cluster, use the following steps:
@advanced_1070_li
@advanced_1071_li
Create a database
@advanced_1071_li
@advanced_1072_li
Use the CreateCluster tool to copy the database to another location and initialize the clustering. Afterwards, you have two databases containing the same data.
@advanced_1072_li
@advanced_1073_li
Start two servers (one for each copy of the database)
@advanced_1073_li
@advanced_1074_li
You are now ready to connect to the databases with the client application(s)
@advanced_1074_h3
@advanced_1075_h3
Using the CreateCluster Tool
@advanced_1075_p
@advanced_1076_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_1076_li
@advanced_1077_li
Create two directories: server1 and server2. Each directory will simulate a directory on a computer.
@advanced_1077_li
@advanced_1078_li
Start a TCP server pointing to the first directory. You can do this using the command line:
@advanced_1078_li
@advanced_1079_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_1079_li
@advanced_1080_li
Use the CreateCluster 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_1080_li
@advanced_1081_li
You can now connect to the databases using an application or the H2 Console using the JDBC URL jdbc:h2:tcp://localhost:9101,localhost:9102/~/test
@advanced_1081_li
@advanced_1082_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_1082_li
@advanced_1083_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 CreateCluster tool.
@advanced_1083_h3
@advanced_1084_h3
Clustering Algorithm and Limitations
@advanced_1084_p
@advanced_1085_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: RANDOM_UUID(), SECURE_RAND(), SESSION_ID(), MEMORY_FREE(), MEMORY_USED(), CSVREAD(), CSVWRITE(), RAND() [when not using a seed]. Those functions should not be used directly in modifying statements (for example INSERT, UPDATE, or MERGE). However, they can be used in read-only statements and the result can then be used for modifying statements.
@advanced_1085_h2
@advanced_1086_h2
Two Phase Commit
@advanced_1086_p
@advanced_1087_p
The two phase commit protocol is supported. 2-phase-commit works as follows:
@advanced_1087_li
@advanced_1088_li
Autocommit needs to be switched off
@advanced_1088_li
@advanced_1089_li
A transaction is started, for example by inserting a row
@advanced_1089_li
@advanced_1090_li
The transaction is marked 'prepared' by executing the SQL statement <code>PREPARE COMMIT transactionName</code>
@advanced_1090_li
@advanced_1091_li
The transaction can now be committed or rolled back
@advanced_1091_li
@advanced_1092_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_1092_li
@advanced_1093_li
When re-connecting to the database, the in-doubt transactions can be listed with <code>SELECT * FROM INFORMATION_SCHEMA.IN_DOUBT</code>
@advanced_1093_li
@advanced_1094_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_1094_li
@advanced_1095_li
The database needs to be closed and re-opened to apply the changes
@advanced_1095_h2
@advanced_1096_h2
Compatibility
@advanced_1096_p
@advanced_1097_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_1097_h3
@advanced_1098_h3
Transaction Commit when Autocommit is On
@advanced_1098_p
@advanced_1099_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_1099_h3
@advanced_1100_h3
Keywords / Reserved Words
@advanced_1100_p
@advanced_1101_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_1101_p
@advanced_1102_p
CURRENT_TIMESTAMP, CURRENT_TIME, CURRENT_DATE, CROSS, DISTINCT, EXCEPT, EXISTS, FROM, FOR, FALSE, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, WHERE
@advanced_1102_p
@advanced_1103_p
Certain words of this list are keywords because they are functions that can be used without '()' for compatibility, for example CURRENT_TIMESTAMP.
@advanced_1103_h2
@advanced_1104_h2
Standards Compliance
@advanced_1105_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_1106_h2
Run as Windows Service
@advanced_1104_p
@advanced_1107_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 Tanuki Software, Inc. ( <a href="http://wrapper.tanukisoftware.org">http://wrapper.tanukisoftware.org</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 H2/service.
@advanced_1105_h3
@advanced_1108_h3
Install the Service
@advanced_1106_p
@advanced_1109_p
The service needs to be registered as a Windows Service first. To do that, double click on 1_install_service.bat. If successful, a command prompt window will pop up and disappear immediately. If not, a message will appear.
@advanced_1107_h3
@advanced_1110_h3
Start the Service
@advanced_1108_p
@advanced_1111_p
You can start the H2 Database Engine Service using the service manager of Windows, or by double clicking on 2_start_service.bat. Please note that the batch file does not print an error message if the service is not installed.
@advanced_1109_h3
@advanced_1112_h3
Connect to the H2 Console
@advanced_1110_p
@advanced_1113_p
After installing and starting the service, you can connect to the H2 Console application using a browser. Double clicking on 3_start_browser.bat to do that. The default port (8082) is hard coded in the batch file.
@advanced_1111_h3
@advanced_1114_h3
Stop the Service
@advanced_1112_p
@advanced_1115_p
To stop the service, double click on 4_stop_service.bat. Please note that the batch file does not print an error message if the service is not installed or started.
@advanced_1113_h3
@advanced_1116_h3
Uninstall the Service
@advanced_1114_p
@advanced_1117_p
To uninstall the service, double click on 5_uninstall_service.bat. If successful, a command prompt window will pop up and disappear immediately. If not, a message will appear.
@advanced_1115_h2
@advanced_1118_h2
ODBC Driver
@advanced_1116_p
@advanced_1119_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_1117_p
@advanced_1120_p
At this time, the PostgreSQL ODBC driver does not work on 64 bit versions of Windows. For more information, see: <a href="http://svr5.postgresql.org/pgsql-odbc/2005-09/msg00127.php">ODBC Driver on Windows 64 bit</a>
@advanced_1118_h3
@advanced_1121_h3
ODBC Installation
@advanced_1119_p
@advanced_1122_p
First, the ODBC driver must be installed. Any recent PostgreSQL ODBC driver should work, however version 8.2.4 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_1120_h3
@advanced_1123_h3
Starting the Server
@advanced_1121_p
@advanced_1124_p
After installing the ODBC driver, start the H2 Server using the command line:
@advanced_1122_p
@advanced_1125_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 -baseDir to save databases in another directory, for example the user home directory:
@advanced_1123_p
@advanced_1126_p
The PG server can be started and stopped from within a Java application as follows:
@advanced_1124_p
@advanced_1127_p
By default, only connections from localhost are allowed. To allow remote connections, use <code>-pgAllowOthers true</code> when starting the server.
@advanced_1125_h3
@advanced_1128_h3
ODBC Configuration
@advanced_1126_p
@advanced_1129_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:
@advanced_1127_th
@advanced_1130_th
Property
@advanced_1128_th
@advanced_1131_th
Example
@advanced_1129_th
@advanced_1132_th
Remarks
@advanced_1130_td
@advanced_1133_td
Data Source
@advanced_1131_td
@advanced_1134_td
H2 Test
@advanced_1132_td
@advanced_1135_td
The name of the ODBC Data Source
@advanced_1133_td
@advanced_1136_td
Database
@advanced_1134_td
@advanced_1137_td
test
@advanced_1135_td
@advanced_1138_td
The database name. Only simple names are supported at this time;
@advanced_1136_td
@advanced_1139_td
relative or absolute path are not supported in the database name.
@advanced_1137_td
@advanced_1140_td
By default, the database is stored in the current working directory
@advanced_1138_td
@advanced_1141_td
where the Server is started except when the -baseDir setting is used.
@advanced_1139_td
@advanced_1142_td
The name must be at least 3 characters.
@advanced_1140_td
@advanced_1143_td
Server
@advanced_1141_td
@advanced_1144_td
localhost
@advanced_1142_td
@advanced_1145_td
The server name or IP address.
@advanced_1143_td
@advanced_1146_td
By default, only remote connections are allowed
@advanced_1144_td
@advanced_1147_td
User Name
@advanced_1145_td
@advanced_1148_td
sa
@advanced_1146_td
@advanced_1149_td
The database user name.
@advanced_1147_td
@advanced_1150_td
SSL Mode
@advanced_1148_td
@advanced_1151_td
disabled
@advanced_1149_td
@advanced_1152_td
At this time, SSL is not supported.
@advanced_1150_td
@advanced_1153_td
Port
@advanced_1151_td
@advanced_1154_td
5435
@advanced_1152_td
@advanced_1155_td
The port where the PG Server is listening.
@advanced_1153_td
@advanced_1156_td
Password
@advanced_1154_td
@advanced_1157_td
sa
@advanced_1155_td
@advanced_1158_td
The database password.
@advanced_1156_p
@advanced_1159_p
Afterwards, you may use this data source.
@advanced_1157_h3
@advanced_1160_h3
PG Protocol Support Limitations
@advanced_1158_p
@advanced_1161_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 cancelled when using the PG protocol.
@advanced_1159_p
@advanced_1162_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_1160_h3
@advanced_1163_h3
Security Considerations
@advanced_1161_p
@advanced_1164_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_1162_h2
@advanced_1165_h2
Using H2 in Microsoft .NET
@advanced_1163_p
@advanced_1166_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_1164_h3
@advanced_1167_h3
Using the ADO.NET API on .NET
@advanced_1165_p
@advanced_1168_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_1166_h3
@advanced_1169_h3
Using the JDBC API on .NET
@advanced_1167_li
@advanced_1170_li
Install the .NET Framework from <a href="http://www.microsoft.com">Microsoft</a> . Mono has not yet been tested.
@advanced_1168_li
@advanced_1171_li
Install <a href="http://www.ikvm.net">IKVM.NET</a> .
@advanced_1169_li
@advanced_1172_li
Copy the h2.jar file to ikvm/bin
@advanced_1170_li
@advanced_1173_li
Run the H2 Console using: <code>ikvm -jar h2.jar</code>
@advanced_1171_li
@advanced_1174_li
Convert the H2 Console to an .exe file using: <code>ikvmc -target:winexe h2.jar</code> . You may ignore the warnings.
@advanced_1172_li
@advanced_1175_li
Create a .dll file using (change the version accordingly): <code>ikvmc.exe -target:library -version:1.0.69.0 h2.jar</code>
@advanced_1173_p
@advanced_1176_p
If you want your C# application use H2, you need to add the h2.dll and the IKVM.OpenJDK.ClassLibrary.dll to your C# solution. Here some sample code:
@advanced_1174_h2
@advanced_1177_h2
ACID
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@advanced_1178_p
In the database world, ACID stands for:
@advanced_1176_li
@advanced_1179_li
Atomicity: Transactions must be atomic, meaning either all tasks are performed or none.
@advanced_1177_li
@advanced_1180_li
Consistency: All operations must comply with the defined constraints.
@advanced_1178_li
@advanced_1181_li
Isolation: Transactions must be isolated from each other.
@advanced_1179_li
@advanced_1182_li
Durability: Committed transaction will not be lost.
@advanced_1180_h3
@advanced_1183_h3
Atomicity
@advanced_1181_p
@advanced_1184_p
Transactions in this database are always atomic.
@advanced_1182_h3
@advanced_1185_h3
Consistency
@advanced_1183_p
@advanced_1186_p
This database is always in a consistent state. Referential integrity rules are always enforced.
@advanced_1184_h3
@advanced_1187_h3
Isolation
@advanced_1185_p
@advanced_1188_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_1186_h3
@advanced_1189_h3
Durability
@advanced_1187_p
@advanced_1190_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_1188_h2
@advanced_1191_h2
Durability Problems
@advanced_1189_p
@advanced_1192_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 org.h2.test.poweroff.Test.
@advanced_1190_h3
@advanced_1193_h3
Ways to (Not) Achieve Durability
@advanced_1191_p
@advanced_1194_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, RandomAccessFile supports the modes "rws" and "rwd":
@advanced_1192_li
@advanced_1195_li
rwd: Every update to the file's content is written synchronously to the underlying storage device.
@advanced_1193_li
@advanced_1196_li
rws: In addition to rwd, every update to the metadata is written synchronously.
@advanced_1194_p
@advanced_1197_p
This feature is used by Derby. A test (org.h2.test.poweroff.TestWrite) 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_1195_p
@advanced_1198_p
Calling fsync flushes the buffers. There are two ways to do that in Java:
@advanced_1196_li
@advanced_1199_li
FileDescriptor.sync(). The documentation says that this forces all system buffers to synchronize with the underlying device. Sync is supposed to return after all in-memory modified copies of buffers associated with this FileDescriptor have been written to the physical medium.
@advanced_1197_li
@advanced_1200_li
FileChannel.force() (since JDK 1.4). This method is supposed to force any updates to this channel's file to be written to the storage device that contains it.
@advanced_1198_p
@advanced_1201_p
By default, MySQL calls fsync 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 FileDescriptor.sync() or FileChannel.force(), data is not always persisted to the hard drive, because most hard drives do not obey fsync(): 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, fsync 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_1199_p
@advanced_1202_p
Trying to flush hard drive buffers 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_1200_p
@advanced_1203_p
In H2, after a power failure, a bit more than one second of committed transactions may be lost. To change the behavior, use SET WRITE_DELAY and CHECKPOINT SYNC. Most other databases support commit delay as well. In the performance comparison, commit delay was used for all databases that support it.
@advanced_1201_h3
@advanced_1204_h3
Running the Durability Test
@advanced_1202_p
@advanced_1205_p
To test the durability / non-durability of this and other databases, you can use the test application in the package org.h2.test.poweroff. 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_1203_h2
@advanced_1206_h2
Using the Recover Tool
@advanced_1204_p
@advanced_1207_p
The recover tool can be used to extract the contents of a data file, even if the database is corrupted. At this time, it does not extract the content of the log file or large objects (CLOB or BLOB). To run the tool, type on the command line:
@advanced_1205_p
@advanced_1208_p
For each database in the current directory, a text file will be created. This file contains raw insert statement (for the data) and data definition (DDL) statement to recreate the schema of the database. This file cannot be executed directly, as the raw insert statements don't have the correct table names, so the file needs to be pre-processed manually before executing.
@advanced_1206_h2
@advanced_1209_h2
File Locking Protocols
@advanced_1207_p
@advanced_1210_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.
@advanced_1208_p
@advanced_1211_p
In special cases (if the process did not terminate normally, for example because there was a blackout), 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_1209_h3
@advanced_1212_h3
File Locking Method 'File'
@advanced_1210_p
@advanced_1213_p
The default method for database file locking is the 'File Method'. The algorithm is:
@advanced_1211_li
@advanced_1214_li
When the lock file does not exist, it is created (using the atomic operation File.createNewFile). Then, the process waits a little bit (20ms) and checks the file again. If the file was changed during this time, the operation is aborted. This protects against a race condition when a process deletes the lock file just after one create it, and a third process creates the file again. It does not occur if there are only two writers.
@advanced_1212_li
@advanced_1215_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_1213_li
@advanced_1216_li
If the lock file exists, and it was modified in the 20 ms, the process waits for some time (up to 10 times). 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_1214_p
@advanced_1217_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_1215_h3
@advanced_1218_h3
File Locking Method 'Socket'
@advanced_1216_p
@advanced_1219_p
There is a second locking mechanism implemented, but disabled by default. The algorithm is:
@advanced_1217_li
@advanced_1220_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_1218_li
@advanced_1221_li
If the lock file exists, and the lock method is 'file', then the software switches to the 'file' method.
@advanced_1219_li
@advanced_1222_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 blackout, or abnormal termination of the virtual machine), then the port was released. The new process deletes the lock file and starts again.
@advanced_1220_p
@advanced_1223_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_1221_h2
@advanced_1224_h2
Protection against SQL Injection
@advanced_1222_h3
@advanced_1225_h3
What is SQL Injection
@advanced_1223_p
@advanced_1226_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_1224_p
@advanced_1227_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: ' OR ''='. In this case the statement becomes:
@advanced_1225_p
@advanced_1228_p
Which is always true no matter what the password stored in the database is. For more information about SQL Injection, see Glossary and Links.
@advanced_1226_h3
@advanced_1229_h3
Disabling Literals
@advanced_1227_p
@advanced_1230_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 PreparedStatement:
@advanced_1228_p
@advanced_1231_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_1229_p
@advanced_1232_p
Afterwards, SQL statements with text and number literals are not allowed any more. That means, SQL statement of the form WHERE NAME='abc' or WHERE CustomerId=10 will fail. It is still possible to use PreparedStatements 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: SET ALLOW_LITERALS NUMBERS. To allow all literals, execute SET ALLOW_LITERALS ALL (this is the default setting). Literals can only be enabled or disabled by an administrator.
@advanced_1230_h3
@advanced_1233_h3
Using Constants
@advanced_1231_p
@advanced_1234_p
Disabling literals also means disabling hard-coded 'constant' literals. This database supports defining constants using the CREATE CONSTANT 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_1232_p
@advanced_1235_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_1233_h3
@advanced_1236_h3
Using the ZERO() Function
@advanced_1234_p
@advanced_1237_p
It is not required to create a constant for the number 0 as there is already a built-in function ZERO():
@advanced_1235_h2
@advanced_1238_h2
Restricting Class Loading and Usage
@advanced_1236_p
@advanced_1239_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 System.setProperty by executing:
@advanced_1237_p
@advanced_1240_p
To restrict users (including admins) from loading classes and executing code, the list of allowed classes can be set in the system property h2.allowedClasses in the form of a comma separated list of classes or patterns (items ending with '*'). By default all classes are allowed. Example:
@advanced_1238_p
@advanced_1241_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_1239_h2
@advanced_1242_h2
Security Protocols
@advanced_1240_p
@advanced_1243_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_1241_h3
@advanced_1244_h3
User Password Encryption
@advanced_1242_p
@advanced_1245_p
When a user tries to connect to a database, the combination of user name, @, and password hashed using SHA-256, and this hash value is transmitted to the database. This step does not try to an attacker from re-using 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_1243_p
@advanced_1246_p
When a new database or user is created, a new cryptographically secure random salt value is generated. The size of the salt is 64 bit. Using the random salt reduces the risk of an attacker pre-calculating hash values for many different (commonly used) passwords.
@advanced_1244_p
@advanced_1247_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 calculated 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 remotely, then the iteration count is not required at all.
@advanced_1245_h3
@advanced_1248_h3
File Encryption
@advanced_1246_p
@advanced_1249_p
The database files can be encrypted using two different algorithms: AES-128 and XTEA (using 32 rounds). The reasons for supporting XTEA is performance (XTEA is about twice as fast as AES) and to have an alternative algorithm if AES is suddenly broken.
@advanced_1247_p
@advanced_1250_p
When a user tries to connect to an encrypted database, the combination of the word 'file', @, and the file password is hashed using SHA-256. This hash value is transmitted to the server.
@advanced_1248_p
@advanced_1251_p
When a new database file is created, a new cryptographically secure random salt value is generated. The size of the salt is 64 bit. 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_1249_p
@advanced_1252_p
The resulting hash value is used as the key for the block cipher algorithm (AES-128 or XTEA with 32 rounds). 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_1250_p
@advanced_1253_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 or XTEA algorithm.
@advanced_1251_p
@advanced_1254_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_1252_p
@advanced_1255_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_1253_p
@advanced_1256_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_1254_p
@advanced_1257_p
File encryption slows down the performance of the database engine. Compared to unencrypted mode, database operations take about 2.2 times longer when using XTEA, and 2.5 times longer using AES (embedded mode).
@advanced_1255_h3
@advanced_1258_h3
Wrong Password Delay
@advanced_1256_p
@advanced_1259_p
To protect against remote brute force password attacks, the delay after each unsuccessful login gets double as long. Use the system properties h2.delayWrongPasswordMin and h2.delayWrongPasswordMax 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 (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_1257_h3
@advanced_1260_h3
SSL/TLS Connections
@advanced_1258_p
@advanced_1261_p
Remote SSL/TLS connections are supported using the Java Secure Socket Extension (SSLServerSocket / SSLSocket). By default, anonymous SSL is enabled. The default cipher suite is <code>SSL_DH_anon_WITH_RC4_128_MD5</code> .
@advanced_1259_p
@advanced_1262_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_1260_p
@advanced_1263_p
To disable anonymous SSL, set the system property <code>h2.enableAnonymousSSL</code> to false.
@advanced_1261_h3
@advanced_1264_h3
HTTPS Connections
@advanced_1262_p
@advanced_1265_p
The web server supports HTTP and HTTPS connections using SSLServerSocket. There is a default self-certified certificate to support an easy starting point, but custom certificates are supported as well.
@advanced_1263_h2
@advanced_1266_h2
Universally Unique Identifiers (UUID)
@advanced_1264_p
@advanced_1267_p
This database supports the 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 RANDOM_UUID(). Here is a small program to estimate the probability of having two identical UUIDs after generating a number of values:
@advanced_1265_p
@advanced_1268_p
Some values are:
@advanced_1266_p
@advanced_1269_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_1267_h2
@advanced_1270_h2
Settings Read from System Properties
@advanced_1268_p
@advanced_1271_p
Some settings of the database can be set on the command line using -DpropertyName=value. It is usually not required to change those settings manually. The settings are case sensitive. Example:
@advanced_1269_p
@advanced_1272_p
The current value of the settings can be read in the table INFORMATION_SCHEMA.SETTINGS.
@advanced_1270_p
@advanced_1273_p
For a complete list of settings, see <a href="../javadoc/org/h2/constant/SysProperties.html">SysProperties</a> .
@advanced_1271_h2
@advanced_1274_h2
Setting the Server Bind Address
@advanced_1272_p
@advanced_1275_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 h2.bindAddress. This setting is used for both regular server sockets and for SSL server sockets. IPv4 and IPv6 address formats are supported.
@advanced_1273_h2
@advanced_1276_h2
Glossary and Links
@advanced_1274_th
@advanced_1277_th
Term
@advanced_1275_th
@advanced_1278_th
Description
@advanced_1276_td
@advanced_1279_td
AES-128
@advanced_1277_td
@advanced_1280_td
A block encryption algorithm. See also: <a href="http://en.wikipedia.org/wiki/Advanced_Encryption_Standard">Wikipedia: AES</a>
@advanced_1278_td
@advanced_1281_td
Birthday Paradox
@advanced_1279_td
@advanced_1282_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_1280_td
@advanced_1283_td
Digest
@advanced_1281_td
@advanced_1284_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_1282_td
@advanced_1285_td
GCJ
@advanced_1283_td
@advanced_1286_td
GNU Compiler for Java. <a href="http://gcc.gnu.org/java/">http://gcc.gnu.org/java/</a> and <a href="http://nativej.mtsystems.ch">http://nativej.mtsystems.ch/ (not free any more)</a>
@advanced_1284_td
@advanced_1287_td
HTTPS
@advanced_1285_td
@advanced_1288_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_1286_td
@advanced_1289_td
Modes of Operation
@advanced_1287_a
@advanced_1290_a
Wikipedia: Block cipher modes of operation
@advanced_1288_td
@advanced_1291_td
Salt
@advanced_1289_td
@advanced_1292_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_1290_td
@advanced_1293_td
SHA-256
@advanced_1291_td
@advanced_1294_td
A cryptographic one-way hash function. See also: <a href="http://en.wikipedia.org/wiki/SHA_family">Wikipedia: SHA hash functions</a>
@advanced_1292_td
@advanced_1295_td
SQL Injection
@advanced_1293_td
@advanced_1296_td
A security vulnerability where an application generates SQL statements with embedded user input. See also: <a href="http://en.wikipedia.org/wiki/SQL_injection">Wikipedia: SQL Injection</a>
@advanced_1294_td
@advanced_1297_td
Watermark Attack
@advanced_1295_td
@advanced_1298_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_1296_td
@advanced_1299_td
SSL/TLS
@advanced_1297_td
@advanced_1300_td
Secure Sockets Layer / Transport Layer Security. See also: <a href="http://java.sun.com/products/jsse/">Java Secure Socket Extension (JSSE)</a>
@advanced_1298_td
@advanced_1301_td
XTEA
@advanced_1299_td
@advanced_1302_td
A block encryption algorithm. See also: <a href="http://en.wikipedia.org/wiki/XTEA">Wikipedia: XTEA</a>
@build_1000_h1
......@@ -1049,7 +1058,7 @@ SLF4J is now supported by using adding TRACE_LEVEL_FILE=4 to the database URL.
The recovery tool did not work if the table name contained spaces or if there was a comment on the table.
@changelog_1015_li
Triggers are no longer executed when executing an changing the table structure (ALTER TABLE).
Triggers are no longer executed when changing the table structure (ALTER TABLE).
@changelog_1016_li
When setting BLOB or CLOB values larger than 65 KB using a remote connection, temporary files were kept on the client longer than required (until the connection was closed or the object is garbage collected). Now they are removed as soon as the PreparedStatement is closed, or when the value is overwritten.
......@@ -3814,6 +3823,9 @@ William Gilbert, USA
@history_1034_li
Antonio Dieguez, Chile
@history_1035_a
Ontology Works, USA
@installation_1000_h1
Installation
......@@ -6323,628 +6335,628 @@ Deferred integrity checking (DEFERRABLE INITIALLY DEFERRED)
Groovy Stored Procedures (http://groovy.codehaus.org/Groovy+SQL)
@roadmap_1037_li
System table / function: cache usage
Linked tables that point to the same database should share the connection ([SHARED])
@roadmap_1038_li
Add a migration guide (list differences between databases)
System table / function: cache usage
@roadmap_1039_li
Optimization: automatic index creation suggestion using the trace file?
Add a migration guide (list differences between databases)
@roadmap_1040_li
Compression performance: don't allocate buffers, compress / expand in to out buffer
Optimization: automatic index creation suggestion using the trace file?
@roadmap_1041_li
Start / stop server with database URL
Compression performance: don't allocate buffers, compress / expand in to out buffer
@roadmap_1042_li
Sequence: add features [NO] MINVALUE, MAXVALUE, CYCLE
Start / stop server with database URL
@roadmap_1043_li
Rebuild index functionality (other than delete the index file)
Sequence: add features [NO] MINVALUE, MAXVALUE, CYCLE
@roadmap_1044_li
Don't use deleteOnExit (bug 4513817: File.deleteOnExit consumes memory)
Rebuild index functionality (other than delete the index file)
@roadmap_1045_li
Console: add accesskey to most important commands (A, AREA, BUTTON, INPUT, LABEL, LEGEND, TEXTAREA)
Don't use deleteOnExit (bug 4513817: File.deleteOnExit consumes memory)
@roadmap_1046_li
Feature: a setting to delete the the log or not (for backup)
Console: add accesskey to most important commands (A, AREA, BUTTON, INPUT, LABEL, LEGEND, TEXTAREA)
@roadmap_1047_li
Test with Sun ASPE1_4; JEE Sun AS PE1.4
Feature: a setting to delete the the log or not (for backup)
@roadmap_1048_li
Test performance again with SQL Server, Oracle, DB2
Test with Sun ASPE1_4; JEE Sun AS PE1.4
@roadmap_1049_li
Test with dbmonster (http://dbmonster.kernelpanic.pl/)
Test performance again with SQL Server, Oracle, DB2
@roadmap_1050_li
Test with dbcopy (http://dbcopyplugin.sourceforge.net)
Test with dbmonster (http://dbmonster.kernelpanic.pl/)
@roadmap_1051_li
Find a tool to view a text file >100 MB, with find, page up and down (like less)
Test with dbcopy (http://dbcopyplugin.sourceforge.net)
@roadmap_1052_li
Implement, test, document XAConnection and so on
Find a tool to view a text file >100 MB, with find, page up and down (like less)
@roadmap_1053_li
Web site: get rid of frame set
Implement, test, document XAConnection and so on
@roadmap_1054_li
Pluggable data type (for compression, validation, conversion, encryption)
Web site: get rid of frame set
@roadmap_1055_li
CHECK: find out what makes CHECK=TRUE slow, move to CHECK2
Pluggable data type (for compression, validation, conversion, encryption)
@roadmap_1056_li
Improve recovery: improve code for log recovery problems (less try/catch)
CHECK: find out what makes CHECK=TRUE slow, move to CHECK2
@roadmap_1057_li
Index usage for (ID, NAME)=(1, 'Hi'); document
Improve recovery: improve code for log recovery problems (less try/catch)
@roadmap_1058_li
Suggestion: include Jetty as Servlet Container (like LAMP)
Index usage for (ID, NAME)=(1, 'Hi'); document
@roadmap_1059_li
Trace shipping to server
Suggestion: include Jetty as Servlet Container (like LAMP)
@roadmap_1060_li
Performance / server mode: use UDP optionally?
Trace shipping to server
@roadmap_1061_li
Version check: docs / web console (using Javascript), and maybe in the library (using TCP/IP)
Performance / server mode: use UDP optionally?
@roadmap_1062_li
Web server classloader: override findResource / getResourceFrom
Version check: docs / web console (using Javascript), and maybe in the library (using TCP/IP)
@roadmap_1063_li
Cost for embedded temporary view is calculated wrong, if result is constant
Web server classloader: override findResource / getResourceFrom
@roadmap_1064_li
Comparison: pluggable sort order: natural sort
Cost for embedded temporary view is calculated wrong, if result is constant
@roadmap_1065_li
Count index range query (count(*) where id between 10 and 20)
Comparison: pluggable sort order: natural sort
@roadmap_1066_li
Eclipse plugin
Count index range query (count(*) where id between 10 and 20)
@roadmap_1067_li
Asynchronous queries to support publish/subscribe: SELECT ... FOR READ WAIT [maxMillisToWait]
Eclipse plugin
@roadmap_1068_li
iReport to support H2
Asynchronous queries to support publish/subscribe: SELECT ... FOR READ WAIT [maxMillisToWait]
@roadmap_1069_li
Implement missing JDBC API (CallableStatement,...)
iReport to support H2
@roadmap_1070_li
Compression of the cache
Implement missing JDBC API (CallableStatement,...)
@roadmap_1071_li
Include SMPT (mail) server (at least client) (alert on cluster failure, low disk space,...)
Compression of the cache
@roadmap_1072_li
Drop with restrict (currently cascade is the default)
Include SMPT (mail) server (at least client) (alert on cluster failure, low disk space,...)
@roadmap_1073_li
JSON parser and functions
Drop with restrict (currently cascade is the default)
@roadmap_1074_li
Automatic collection of statistics (auto ANALYZE)
JSON parser and functions
@roadmap_1075_li
Server: client ping from time to time (to avoid timeout - is timeout a problem?)
Automatic collection of statistics (auto ANALYZE)
@roadmap_1076_li
Copy database: Tool with config GUI and batch mode, extensible (example: compare)
Server: client ping from time to time (to avoid timeout - is timeout a problem?)
@roadmap_1077_li
Document, implement tool for long running transactions using user-defined compensation statements
Copy database: Tool with config GUI and batch mode, extensible (example: compare)
@roadmap_1078_li
Support SET TABLE DUAL READONLY
Document, implement tool for long running transactions using user-defined compensation statements
@roadmap_1079_li
Linked schema using CSV files: one schema for a directory of files; support indexes for CSV files
Support SET TABLE DUAL READONLY
@roadmap_1080_li
Don't write stack traces for common exceptions like duplicate key to the log by default
Linked schema using CSV files: one schema for a directory of files; support indexes for CSV files
@roadmap_1081_li
GCJ: what is the state now?
Don't write stack traces for common exceptions like duplicate key to the log by default
@roadmap_1082_li
Use Janino to convert Java to C++
GCJ: what is the state now?
@roadmap_1083_li
Reduce disk space usage (Derby uses less disk space?)
Use Janino to convert Java to C++
@roadmap_1084_li
Events for: Database Startup, Connections, Login attempts, Disconnections, Prepare (after parsing), Web Server (see http://docs.openlinksw.com/virtuoso/fn_dbev_startup.html)
Reduce disk space usage (Derby uses less disk space?)
@roadmap_1085_li
Optimization: Log compression
Events for: Database Startup, Connections, Login attempts, Disconnections, Prepare (after parsing), Web Server (see http://docs.openlinksw.com/virtuoso/fn_dbev_startup.html)
@roadmap_1086_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)
Optimization: Log compression
@roadmap_1087_li
Compatibility: in MySQL, HSQLDB, /0.0 is NULL; in PostgreSQL, Derby: Division by zero
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_1088_li
Functional tables should accept parameters from other tables (see FunctionMultiReturn) SELECT * FROM TEST T, P2C(T.A, T.R)
Compatibility: in MySQL, HSQLDB, /0.0 is NULL; in PostgreSQL, Derby: Division by zero
@roadmap_1089_li
Custom class loader to reload functions on demand
Functional tables should accept parameters from other tables (see FunctionMultiReturn) SELECT * FROM TEST T, P2C(T.A, T.R)
@roadmap_1090_li
Test http://mysql-je.sourceforge.net/
Custom class loader to reload functions on demand
@roadmap_1091_li
Close all files when closing the database (including LOB files that are open on the client side)
Test http://mysql-je.sourceforge.net/
@roadmap_1092_li
EXE file: maybe use http://jsmooth.sourceforge.net
Close all files when closing the database (including LOB files that are open on the client side)
@roadmap_1093_li
Performance: Automatically build in-memory indexes if the whole table is in memory
EXE file: maybe use http://jsmooth.sourceforge.net
@roadmap_1094_li
H2 Console: The webclient could support more features like phpMyAdmin.
Performance: Automatically build in-memory indexes if the whole table is in memory
@roadmap_1095_li
The HELP information schema can be directly exposed in the Console
H2 Console: The webclient could support more features like phpMyAdmin.
@roadmap_1096_li
Maybe use the 0x1234 notation for binary fields, see MS SQL Server
The HELP information schema can be directly exposed in the Console
@roadmap_1097_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
Maybe use the 0x1234 notation for binary fields, see MS SQL Server
@roadmap_1098_li
SQL 2003 (http://www.wiscorp.com/sql_2003_standard.zip)
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_1099_li
http://www.jpackage.org
SQL 2003 (http://www.wiscorp.com/sql_2003_standard.zip)
@roadmap_1100_li
Version column (number/sequence and timestamp based)
http://www.jpackage.org
@roadmap_1101_li
Optimize getGeneratedKey: send last identity after each execute (server).
Version column (number/sequence and timestamp based)
@roadmap_1102_li
Date: default date is '1970-01-01' (is it 1900-01-01 in the standard / other databases?)
Optimize getGeneratedKey: send last identity after each execute (server).
@roadmap_1103_li
Test and document UPDATE TEST SET (ID, NAME) = (SELECT ID*10, NAME || '!' FROM TEST T WHERE T.ID=TEST.ID);
Date: default date is '1970-01-01' (is it 1900-01-01 in the standard / other databases?)
@roadmap_1104_li
Max memory rows / max undo log size: use block count / row size not row count
Test and document UPDATE TEST SET (ID, NAME) = (SELECT ID*10, NAME || '!' FROM TEST T WHERE T.ID=TEST.ID);
@roadmap_1105_li
Support 123L syntax as in Java; example: SELECT (2000000000*2)
Max memory rows / max undo log size: use block count / row size not row count
@roadmap_1106_li
Implement point-in-time recovery
Support 123L syntax as in Java; example: SELECT (2000000000*2)
@roadmap_1107_li
Include the version name in the jar file name
Implement point-in-time recovery
@roadmap_1108_li
Optimize ID=? OR ID=?: convert to IN(...)
Include the version name in the jar file name
@roadmap_1109_li
LIKE: improved version for larger texts (currently using naive search)
Optimize ID=? OR ID=?: convert to IN(...)
@roadmap_1110_li
Auto-reconnect on lost connection to server (even if the server was re-started) except if autocommit was off and there was pending transaction
LIKE: improved version for larger texts (currently using naive search)
@roadmap_1111_li
The Script tool should work with other databases as well
Auto-reconnect on lost connection to server (even if the server was re-started) except if autocommit was off and there was pending transaction
@roadmap_1112_li
Automatically convert to the next 'higher' data type whenever there is an overflow.
The Script tool should work with other databases as well
@roadmap_1113_li
Throw an exception when the application calls getInt on a Long (optional)
Automatically convert to the next 'higher' data type whenever there is an overflow.
@roadmap_1114_li
Default date format for input and output (local date constants)
Throw an exception when the application calls getInt on a Long (optional)
@roadmap_1115_li
ValueInt.convertToString and so on (remove Value.convertTo)
Default date format for input and output (local date constants)
@roadmap_1116_li
Support custom Collators
ValueInt.convertToString and so on (remove Value.convertTo)
@roadmap_1117_li
Document ROWNUM usage for reports: SELECT ROWNUM, * FROM (subquery)
Support custom Collators
@roadmap_1118_li
Clustering: Reads should be randomly distributed or to a designated database on RAM
Document ROWNUM usage for reports: SELECT ROWNUM, * FROM (subquery)
@roadmap_1119_li
Clustering: When a database is back alive, automatically synchronize with the master
Clustering: Reads should be randomly distributed or to a designated database on RAM
@roadmap_1120_li
Standalone tool to get relevant system properties and add it to the trace output.
Clustering: When a database is back alive, automatically synchronize with the master
@roadmap_1121_li
Support mixed clustering mode (one embedded, the other server mode)
Standalone tool to get relevant system properties and add it to the trace output.
@roadmap_1122_li
Support 'call proc(1=value)' (PostgreSQL, Oracle)
Support mixed clustering mode (one embedded, the other server mode)
@roadmap_1123_li
JAMon (proxy jdbc driver)
Support 'call proc(1=value)' (PostgreSQL, Oracle)
@roadmap_1124_li
Console: Improve editing data (Tab, Shift-Tab, Enter, Up, Down, Shift+Del?)
JAMon (proxy jdbc driver)
@roadmap_1125_li
Console: Autocomplete Ctrl+Space inserts template
Console: Improve editing data (Tab, Shift-Tab, Enter, Up, Down, Shift+Del?)
@roadmap_1126_li
Simplify translation ('Donate a translation')
Console: Autocomplete Ctrl+Space inserts template
@roadmap_1127_li
Option to encrypt .trace.db file
Simplify translation ('Donate a translation')
@roadmap_1128_li
Write Behind Cache on SATA leads to data corruption See also http://sr5tech.com/write_back_cache_experiments.htm and http://www.jasonbrome.com/blog/archives/2004/04/03/writecache_enabled.html
Option to encrypt .trace.db file
@roadmap_1129_li
Functions with unknown return or parameter data types: serialize / deserialize
Write Behind Cache on SATA leads to data corruption See also http://sr5tech.com/write_back_cache_experiments.htm and http://www.jasonbrome.com/blog/archives/2004/04/03/writecache_enabled.html
@roadmap_1130_li
Test if idle TCP connections are closed, and how to disable that
Functions with unknown return or parameter data types: serialize / deserialize
@roadmap_1131_li
Try using a factory for Row, Value[] (faster?), http://javolution.org/, alternative ObjectArray / IntArray
Test if idle TCP connections are closed, and how to disable that
@roadmap_1132_li
Auto-Update feature for database, .jar file
Try using a factory for Row, Value[] (faster?), http://javolution.org/, alternative ObjectArray / IntArray
@roadmap_1133_li
ResultSet SimpleResultSet.readFromURL(String url): id varchar, state varchar, released timestamp
Auto-Update feature for database, .jar file
@roadmap_1134_li
RANK() and DENSE_RANK(), Partition using OVER()
ResultSet SimpleResultSet.readFromURL(String url): id varchar, state varchar, released timestamp
@roadmap_1135_li
ROW_NUMBER (not the same as ROWNUM)
RANK() and DENSE_RANK(), Partition using OVER()
@roadmap_1136_li
Partial indexing (see PostgreSQL)
ROW_NUMBER (not the same as ROWNUM)
@roadmap_1137_li
The build should fail if the test fails
Partial indexing (see PostgreSQL)
@roadmap_1138_li
http://rubyforge.org/projects/hypersonic/
The build should fail if the test fails
@roadmap_1139_li
DbVisualizer profile for H2
http://rubyforge.org/projects/hypersonic/
@roadmap_1140_li
Add comparator (x === y) : (x = y or (x is null and y is null))
DbVisualizer profile for H2
@roadmap_1141_li
Try to create trace file even for read only databases
Add comparator (x === y) : (x = y or (x is null and y is null))
@roadmap_1142_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)
Try to create trace file even for read only databases
@roadmap_1143_li
Count on a column that can not be null would be optimized to COUNT(*)
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_1144_li
Table order: ALTER TABLE TEST ORDER BY NAME DESC (MySQL compatibility)
Count on a column that can not be null would be optimized to COUNT(*)
@roadmap_1145_li
Backup tool should work with other databases as well
Table order: ALTER TABLE TEST ORDER BY NAME DESC (MySQL compatibility)
@roadmap_1146_li
Console: -ifExists doesn't work for the console. Add a flag to disable other dbs
Backup tool should work with other databases as well
@roadmap_1147_li
Improved full text search (supports LOBs, reader / tokenizer / filter).
Console: -ifExists doesn't work for the console. Add a flag to disable other dbs
@roadmap_1148_li
Performance: Update in-place
Improved full text search (supports LOBs, reader / tokenizer / filter).
@roadmap_1149_li
Check if 'FSUTIL behavior set disablelastaccess 1' improves the performance (fsutil behavior query disablelastaccess)
Performance: Update in-place
@roadmap_1150_li
Java static code analysis: http://pmd.sourceforge.net/
Check if 'FSUTIL behavior set disablelastaccess 1' improves the performance (fsutil behavior query disablelastaccess)
@roadmap_1151_li
Java static code analysis: http://www.eclipse.org/tptp/
Java static code analysis: http://pmd.sourceforge.net/
@roadmap_1152_li
Compatibility for CREATE SCHEMA AUTHORIZATION
Java static code analysis: http://www.eclipse.org/tptp/
@roadmap_1153_li
Implement Clob / Blob truncate and the remaining functionality
Compatibility for CREATE SCHEMA AUTHORIZATION
@roadmap_1154_li
Maybe close LOBs after closing connection
Implement Clob / Blob truncate and the remaining functionality
@roadmap_1155_li
Tree join functionality
Maybe close LOBs after closing connection
@roadmap_1156_li
Support alter table add column if table has views defined
Tree join functionality
@roadmap_1157_li
Add multiple columns at the same time with ALTER TABLE .. ADD .. ADD ..
Support alter table add column if table has views defined
@roadmap_1158_li
Support trigger on the tables information_schema.tables and ...columns
Add multiple columns at the same time with ALTER TABLE .. ADD .. ADD ..
@roadmap_1159_li
Add H2 to Gem (Ruby install system)
Support trigger on the tables information_schema.tables and ...columns
@roadmap_1160_li
API for functions / user tables
Add H2 to Gem (Ruby install system)
@roadmap_1161_li
Order conditions inside AND / OR to optimize the performance
API for functions / user tables
@roadmap_1162_li
Support linked JCR tables
Order conditions inside AND / OR to optimize the performance
@roadmap_1163_li
Make sure H2 is supported by Execute Query: http://executequery.org/
Support linked JCR tables
@roadmap_1164_li
Read InputStream when executing, as late as possible (maybe only embedded mode). Problem with re-execute.
Make sure H2 is supported by Execute Query: http://executequery.org/
@roadmap_1165_li
Full text search: min word length; store word positions
Read InputStream when executing, as late as possible (maybe only embedded mode). Problem with re-execute.
@roadmap_1166_li
FTP Server: Implement a client to send / receive files to server (dir, get, put)
Full text search: min word length; store word positions
@roadmap_1167_li
FTP Server: Implement SFTP / FTPS
FTP Server: Implement a client to send / receive files to server (dir, get, put)
@roadmap_1168_li
Add an option to the SCRIPT command to generate only portable / standard SQL
FTP Server: Implement SFTP / FTPS
@roadmap_1169_li
Test Dezign for Databases (http://www.datanamic.com)
Add an option to the SCRIPT command to generate only portable / standard SQL
@roadmap_1170_li
Fast library for parsing / formatting: http://javolution.org/
Test Dezign for Databases (http://www.datanamic.com)
@roadmap_1171_li
Updatable Views (simple cases first)
Fast library for parsing / formatting: http://javolution.org/
@roadmap_1172_li
Improve create index performance
Updatable Views (simple cases first)
@roadmap_1173_li
Support ARRAY data type
Improve create index performance
@roadmap_1174_li
Implement more JDBC 4.0 features
Support ARRAY data type
@roadmap_1175_li
Support TRANSFORM / PIVOT as in MS Access
Implement more JDBC 4.0 features
@roadmap_1176_li
SELECT * FROM (VALUES (...), (...), ....) AS alias(f1, ...)
Support TRANSFORM / PIVOT as in MS Access
@roadmap_1177_li
Support updatable views with join on primary keys (to extend a table)
SELECT * FROM (VALUES (...), (...), ....) AS alias(f1, ...)
@roadmap_1178_li
Public interface for functions (not public static)
Support updatable views with join on primary keys (to extend a table)
@roadmap_1179_li
Autocomplete: if I type the name of a table that does not exist (should say: syntax not supported)
Public interface for functions (not public static)
@roadmap_1180_li
Document FTP server, including -ftpTask option to execute / kill remote processes
Autocomplete: if I type the name of a table that does not exist (should say: syntax not supported)
@roadmap_1181_li
Eliminate undo log records if stored on disk (just one pointer per block, not per record)
Document FTP server, including -ftpTask option to execute / kill remote processes
@roadmap_1182_li
Feature matrix like in <a href="http://www.inetsoftware.de/products/jdbc/mssql/features/default.asp">i-net software</a> .
Eliminate undo log records if stored on disk (just one pointer per block, not per record)
@roadmap_1183_li
Updatable result set on table without primary key or unique index
Feature matrix like in <a href="http://www.inetsoftware.de/products/jdbc/mssql/features/default.asp">i-net software</a> .
@roadmap_1184_li
Use LinkedList instead of ArrayList where applicable
Updatable result set on table without primary key or unique index
@roadmap_1185_li
Support % operator (modulo)
Use LinkedList instead of ArrayList where applicable
@roadmap_1186_li
Support 1+'2'=3, '1'+'2'='12' (MS SQL Server compatibility)
Support % operator (modulo)
@roadmap_1187_li
Support nested transactions
Support 1+'2'=3, '1'+'2'='12' (MS SQL Server compatibility)
@roadmap_1188_li
Add a benchmark for big databases, and one for many users
Support nested transactions
@roadmap_1189_li
Compression in the result set (repeating values in the same column)
Add a benchmark for big databases, and one for many users
@roadmap_1190_li
Support curtimestamp (like curtime, curdate)
Compression in the result set (repeating values in the same column)
@roadmap_1191_li
Support ANALYZE {TABLE|INDEX} tableName COMPUTE|ESTIMATE|DELETE STATISTICS ptnOption options
Support curtimestamp (like curtime, curdate)
@roadmap_1192_li
Support Sequoia (Continuent.org)
Support ANALYZE {TABLE|INDEX} tableName COMPUTE|ESTIMATE|DELETE STATISTICS ptnOption options
@roadmap_1193_li
Dynamic length numbers / special methods for DataPage.writeByte / writeShort / Ronni Nielsen
Support Sequoia (Continuent.org)
@roadmap_1194_li
Pluggable ThreadPool, (AvalonDB / deebee / Paul Hammant)
Dynamic length numbers / special methods for DataPage.writeByte / writeShort / Ronni Nielsen
@roadmap_1195_li
Recursive Queries (see details)
Pluggable ThreadPool, (AvalonDB / deebee / Paul Hammant)
@roadmap_1196_li
Add GUI to build a custom version (embedded, fulltext,...)
Recursive Queries (see details)
@roadmap_1197_li
Release locks (shared or exclusive) on demand
Add GUI to build a custom version (embedded, fulltext,...)
@roadmap_1198_li
Support OUTER UNION
Release locks (shared or exclusive) on demand
@roadmap_1199_li
Support Parameterized Views (similar to CSVREAD, but using just SQL for the definition)
Support OUTER UNION
@roadmap_1200_li
A way (JDBC driver) to map an URL (jdbc:h2map:c1) to a connection object
Support Parameterized Views (similar to CSVREAD, but using just SQL for the definition)
@roadmap_1201_li
Option for SCRIPT to only process one or a set of tables, and append to a file
A way (JDBC driver) to map an URL (jdbc:h2map:c1) to a connection object
@roadmap_1202_li
Support using a unique index for IS NULL (including linked tables)
Option for SCRIPT to only process one or a set of tables, and append to a file
@roadmap_1203_li
Support linked tables to the current database
Support using a unique index for IS NULL (including linked tables)
@roadmap_1204_li
Support dynamic linked schema (automatically adding/updating/removing tables)
Support linked tables to the current database
@roadmap_1205_li
Compatibility with Derby: VALUES(1), (2); SELECT * FROM (VALUES (1), (2)) AS myTable(c1)
Support dynamic linked schema (automatically adding/updating/removing tables)
@roadmap_1206_li
Compatibility: # is the start of a single line comment (MySQL) but date quote (Access). Mode specific
Compatibility with Derby: VALUES(1), (2); SELECT * FROM (VALUES (1), (2)) AS myTable(c1)
@roadmap_1207_li
Run benchmarks with JDK 1.5, JDK 1.6, java -server
Compatibility: # is the start of a single line comment (MySQL) but date quote (Access). Mode specific
@roadmap_1208_li
Optimizations: Faster hash function for strings, byte arrays, big decimal
Run benchmarks with JDK 1.5, JDK 1.6, java -server
@roadmap_1209_li
DatabaseEventListener: callback for all operations (including expected time, RUNSCRIPT) and cancel functionality
Optimizations: Faster hash function for strings, byte arrays, big decimal
@roadmap_1210_li
H2 Console / large result sets: use 'streaming' instead of building the page in-memory
DatabaseEventListener: callback for all operations (including expected time, RUNSCRIPT) and cancel functionality
@roadmap_1211_li
Benchmark: add a graph to show how databases scale (performance/database size)
H2 Console / large result sets: use 'streaming' instead of building the page in-memory
@roadmap_1212_li
Implement a SQLData interface to map your data over to a custom object
Benchmark: add a graph to show how databases scale (performance/database size)
@roadmap_1213_li
Make DDL (Data Definition) operations transactional
Implement a SQLData interface to map your data over to a custom object
@roadmap_1214_li
Allow execution time prepare for SELECT * FROM CSVREAD(?, 'columnNameString')
Make DDL (Data Definition) operations transactional
@roadmap_1215_li
Support multiple directories (on different hard drives) for the same database
Allow execution time prepare for SELECT * FROM CSVREAD(?, 'columnNameString')
@roadmap_1216_li
Server protocol: use challenge response authentication, but client sends hash(user+password) encrypted with response
Support multiple directories (on different hard drives) for the same database
@roadmap_1217_li
Support EXEC[UTE] (doesn't return a result set, compatible to MS SQL Server)
Server protocol: use challenge response authentication, but client sends hash(user+password) encrypted with response
@roadmap_1218_li
GROUP BY and DISTINCT: support large groups (buffer to disk), do not keep large sets in memory
Support EXEC[UTE] (doesn't return a result set, compatible to MS SQL Server)
@roadmap_1219_li
Support native XML data type
GROUP BY and DISTINCT: support large groups (buffer to disk), do not keep large sets in memory
@roadmap_1220_li
Support triggers with a string property or option: SpringTrigger, OSGITrigger
Support native XML data type
@roadmap_1221_li
Clustering: adding a node should be very fast and without interrupting clients (very short lock)
Support triggers with a string property or option: SpringTrigger, OSGITrigger
@roadmap_1222_li
Support materialized views (using triggers)
Clustering: adding a node should be very fast and without interrupting clients (very short lock)
@roadmap_1223_li
Store dates in local time zone (portability of database files)
Support materialized views (using triggers)
@roadmap_1224_li
Ability to resize the cache array when resizing the cache
Store dates in local time zone (portability of database files)
@roadmap_1225_li
Time based cache writing (one second after writing the log)
Ability to resize the cache array when resizing the cache
@roadmap_1226_li
Check state of H2 driver for DDLUtils: https://issues.apache.org/jira/browse/DDLUTILS-185
Time based cache writing (one second after writing the log)
@roadmap_1227_li
Index usage for REGEXP LIKE.
Check state of H2 driver for DDLUtils: https://issues.apache.org/jira/browse/DDLUTILS-185
@roadmap_1228_li
Add a role DBA (like ADMIN).
Index usage for REGEXP LIKE.
@roadmap_1229_li
Better support multiple processors for in-memory databases.
Add a role DBA (like ADMIN).
@roadmap_1230_li
Access rights: remember the owner of an object. COMMENT: allow owner of object to change it.
Better support multiple processors for in-memory databases.
@roadmap_1231_li
Implement INSTEAD OF trigger.
Access rights: remember the owner of an object. COMMENT: allow owner of object to change it.
@roadmap_1232_li
Access rights: Finer grained access control (grant access for specific functions)
Implement INSTEAD OF trigger.
@roadmap_1233_li
Support N'text'
Access rights: Finer grained access control (grant access for specific functions)
@roadmap_1234_li
Support SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger
Support N'text'
@roadmap_1235_li
Set a connection read only (Connection.setReadOnly)
Support SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger
@roadmap_1236_li
In MySQL mode, for AUTO_INCREMENT columns, don't set the primary key
Set a connection read only (Connection.setReadOnly)
@roadmap_1237_li
Use JDK 1.4 file locking to create the lock file (but not yet by default); writing a system property to detect concurrent access from the same VM (different classloaders).
In MySQL mode, for AUTO_INCREMENT columns, don't set the primary key
@roadmap_1238_li
Support compatibility for jdbc:hsqldb:res:
Use JDK 1.4 file locking to create the lock file (but not yet by default); writing a system property to detect concurrent access from the same VM (different classloaders).
@roadmap_1239_li
In the MySQL and PostgreSQL, use lower case identifiers by default (DatabaseMetaData.storesLowerCaseIdentifiers = true)
Support compatibility for jdbc:hsqldb:res:
@roadmap_1240_li
Provide a simple, lightweight O/R mapping tool
In the MySQL and PostgreSQL, use lower case identifiers by default (DatabaseMetaData.storesLowerCaseIdentifiers = true)
@roadmap_1241_li
Provide an Java SQL builder with standard and H2 syntax
Provide a simple, lightweight O/R mapping tool
@roadmap_1242_li
Trace: write OS, file system, JVM,... when opening the database
Provide an Java SQL builder with standard and H2 syntax
@roadmap_1243_li
Support indexes for views (probably requires materialized views)
Trace: write OS, file system, JVM,... when opening the database
@roadmap_1244_li
Linked tables that point to the same database should share the connection
Support indexes for views (probably requires materialized views)
@roadmap_1245_li
Document SET SEARCH_PATH, BEGIN, EXECUTE, parameters
......
h2/src/docsrc/text/_docs_ja.utf8.txt
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h2/src/docsrc/textbase/_docs_en.properties
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h2/src/main/org/h2/fulltext/FullText.java
浏览文件 @ 42ed3064
......@@ -439,11 +439,12 @@ public class FullText implements Trigger {
case Types.CHAR:
case Types.VARCHAR:
return data.toString();
case Types.CLOB:
int test;
case Types.VARBINARY:
case Types.LONGVARBINARY:
case Types.BINARY:
case Types.JAVA_OBJECT:
case Types.CLOB:
case Types.OTHER:
case Types.BLOB:
case Types.STRUCT:
......@@ -486,8 +487,9 @@ public class FullText implements Trigger {
case Types.LONGVARBINARY:
case Types.BINARY:
return quoteBinary((byte[]) data);
case Types.JAVA_OBJECT:
case Types.CLOB:
int test;
case Types.JAVA_OBJECT:
case Types.OTHER:
case Types.BLOB:
case Types.STRUCT:
......
h2/src/main/org/h2/fulltext/FullTextLucene.java
浏览文件 @ 42ed3064
......@@ -425,11 +425,12 @@ implements Trigger
case Types.CHAR:
case Types.VARCHAR:
return data.toString();
case Types.CLOB:
int todo;
case Types.VARBINARY:
case Types.LONGVARBINARY:
case Types.BINARY:
case Types.JAVA_OBJECT:
case Types.CLOB:
case Types.OTHER:
case Types.BLOB:
case Types.STRUCT:
......@@ -471,8 +472,9 @@ implements Trigger
case Types.LONGVARBINARY:
case Types.BINARY:
return quoteBinary((byte[]) data);
case Types.JAVA_OBJECT:
case Types.CLOB:
int test;
case Types.JAVA_OBJECT:
case Types.OTHER:
case Types.BLOB:
case Types.STRUCT:
......
h2/src/main/org/h2/index/BaseIndex.java
浏览文件 @ 42ed3064
......@@ -38,7 +38,7 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
protected long rowCount;
protected boolean isMultiVersion;
public void initBaseIndex(Table table, int id, String name, IndexColumn[] indexColumns, IndexType indexType) {
void initBaseIndex(Table table, int id, String name, IndexColumn[] indexColumns, IndexType indexType) {
initSchemaObjectBase(table.getSchema(), id, name, Trace.INDEX);
this.indexType = indexType;
this.table = table;
......@@ -342,7 +342,7 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
public void commit(int operation, Row row) throws SQLException {
}
public void setMultiVersion(boolean multiVersion) {
void setMultiVersion(boolean multiVersion) {
this.isMultiVersion = multiVersion;
}
......
h2/src/main/org/h2/index/BtreeIndex.java
浏览文件 @ 42ed3064
......@@ -55,9 +55,21 @@ public class BtreeIndex extends BaseIndex implements RecordReader {
private int headPos;
private long lastChange;
/**
* Create a new b tree index with the given properties. If the index does
* not yet exist, a new empty one is created.
*
* @param session the session
* @param table the base table
* @param id the object id
* @param indexName the name of the index
* @param columns the indexed columns
* @param indexType the index type
* @param headPos the position of the index header page, or Index.EMPTY_HEAD
* for a new index
*/
public BtreeIndex(Session session, TableData table, int id, String indexName, IndexColumn[] columns,
IndexType indexType, int headPos) throws SQLException {
// TODO we need to log index data
initBaseIndex(table, id, indexName, columns, indexType);
this.tableData = table;
Database db = table.getDatabase();
......@@ -142,6 +154,11 @@ public class BtreeIndex extends BaseIndex implements RecordReader {
return (BtreePage) storage.getRecord(session, i);
}
/**
* Write all changed paged to disk and mark the index as valid.
*
* @param session the session
*/
public void flush(Session session) throws SQLException {
lastChange = 0;
if (storage != null) {
......@@ -320,6 +337,11 @@ public class BtreeIndex extends BaseIndex implements RecordReader {
return storage.getRecordOverhead();
}
/**
* Get the last change time or 0 if the index has not been changed.
*
* @return the last change time or 0
*/
public long getLastChange() {
return lastChange;
}
......
h2/src/main/org/h2/index/BtreeLeaf.java
浏览文件 @ 42ed3064
......@@ -55,7 +55,7 @@ public class BtreeLeaf extends BtreePage {
this.pageData = pageData;
}
public int add(Row newRow, Session session) throws SQLException {
int add(Row newRow, Session session) throws SQLException {
int l = 0, r = pageData.size();
while (l < r) {
int i = (l + r) >>> 1;
......@@ -88,7 +88,7 @@ public class BtreeLeaf extends BtreePage {
return splitPoint;
}
public SearchRow remove(Session session, Row oldRow) throws SQLException {
SearchRow remove(Session session, Row oldRow) throws SQLException {
int l = 0, r = pageData.size();
if (r == 0) {
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && !root) {
......@@ -134,7 +134,7 @@ public class BtreeLeaf extends BtreePage {
throw Message.getSQLException(ErrorCode.ROW_NOT_FOUND_WHEN_DELETING_1, index.getSQL());
}
public BtreePage split(Session session, int splitPoint) throws SQLException {
BtreePage split(Session session, int splitPoint) throws SQLException {
ObjectArray data = new ObjectArray();
int max = pageData.size();
for (int i = splitPoint; i < max; i++) {
......@@ -148,7 +148,7 @@ public class BtreeLeaf extends BtreePage {
return n2;
}
public boolean findFirst(BtreeCursor cursor, SearchRow compare, boolean bigger) throws SQLException {
boolean findFirst(BtreeCursor cursor, SearchRow compare, boolean bigger) throws SQLException {
int l = 0, r = pageData.size();
if (r == 0 && !Constants.ALLOW_EMPTY_BTREE_PAGES && !root) {
throw Message.getInternalError("Empty btree page");
......@@ -172,7 +172,7 @@ public class BtreeLeaf extends BtreePage {
return true;
}
public void next(BtreeCursor cursor, int i) throws SQLException {
void next(BtreeCursor cursor, int i) throws SQLException {
i++;
if (i < pageData.size()) {
SearchRow r = (SearchRow) pageData.get(i);
......@@ -184,7 +184,7 @@ public class BtreeLeaf extends BtreePage {
nextUpper(cursor);
}
public void previous(BtreeCursor cursor, int i) throws SQLException {
void previous(BtreeCursor cursor, int i) throws SQLException {
i--;
if (i >= 0) {
SearchRow r = (SearchRow) pageData.get(i);
......@@ -196,7 +196,7 @@ public class BtreeLeaf extends BtreePage {
previousUpper(cursor);
}
public void first(BtreeCursor cursor) throws SQLException {
void first(BtreeCursor cursor) throws SQLException {
if (pageData.size() == 0) {
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && !root) {
throw Message.getInternalError("Empty btree page");
......@@ -209,7 +209,7 @@ public class BtreeLeaf extends BtreePage {
cursor.setCurrentRow(row);
}
public void last(BtreeCursor cursor) throws SQLException {
void last(BtreeCursor cursor) throws SQLException {
int last = pageData.size() - 1;
if (last < 0) {
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && !root) {
......@@ -284,7 +284,7 @@ public class BtreeLeaf extends BtreePage {
}
}
public int getRealByteCount() throws SQLException {
int getRealByteCount() throws SQLException {
if (cachedRealByteCount > 0) {
return cachedRealByteCount;
}
......
h2/src/main/org/h2/index/BtreeNode.java
浏览文件 @ 42ed3064
......@@ -72,7 +72,7 @@ public class BtreeNode extends BtreePage {
return r;
}
public int add(Row newRow, Session session) throws SQLException {
int add(Row newRow, Session session) throws SQLException {
int l = 0, r = pageData.size();
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && pageChildren.size() == 0) {
throw Message.getInternalError("Empty btree page");
......@@ -114,7 +114,7 @@ public class BtreeNode extends BtreePage {
return 0;
}
public SearchRow remove(Session session, Row oldRow) throws SQLException {
SearchRow remove(Session session, Row oldRow) throws SQLException {
int l = 0, r = pageData.size();
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && pageChildren.size() == 0) {
throw Message.getInternalError("Empty btree page");
......@@ -180,7 +180,7 @@ public class BtreeNode extends BtreePage {
}
}
public BtreePage split(Session session, int splitPoint) throws SQLException {
BtreePage split(Session session, int splitPoint) throws SQLException {
ObjectArray data = new ObjectArray();
IntArray children = new IntArray();
splitPoint++;
......@@ -209,7 +209,7 @@ public class BtreeNode extends BtreePage {
return pageChildren.get(i);
}
public boolean findFirst(BtreeCursor cursor, SearchRow compare, boolean bigger) throws SQLException {
boolean findFirst(BtreeCursor cursor, SearchRow compare, boolean bigger) throws SQLException {
int l = 0, r = pageData.size();
if (!Constants.ALLOW_EMPTY_BTREE_PAGES && pageChildren.size() == 0) {
throw Message.getInternalError("Empty btree page");
......@@ -263,7 +263,7 @@ public class BtreeNode extends BtreePage {
return false;
}
public void next(BtreeCursor cursor, int i) throws SQLException {
void next(BtreeCursor cursor, int i) throws SQLException {
i++;
if (i <= pageData.size()) {
cursor.setStackPosition(i);
......@@ -274,7 +274,7 @@ public class BtreeNode extends BtreePage {
nextUpper(cursor);
}
public void previous(BtreeCursor cursor, int i) throws SQLException {
void previous(BtreeCursor cursor, int i) throws SQLException {
i--;
if (i >= 0) {
cursor.setStackPosition(i);
......@@ -307,13 +307,13 @@ public class BtreeNode extends BtreePage {
}
}
public void first(BtreeCursor cursor) throws SQLException {
void first(BtreeCursor cursor) throws SQLException {
cursor.push(this, 0);
BtreePage page = index.getPage(cursor.getSession(), pageChildren.get(0));
page.first(cursor);
}
public void last(BtreeCursor cursor) throws SQLException {
void last(BtreeCursor cursor) throws SQLException {
int last = pageChildren.size() - 1;
cursor.push(this, last);
BtreePage page = index.getPage(cursor.getSession(), pageChildren.get(last));
......
h2/src/main/org/h2/log/InDoubtTransaction.java
浏览文件 @ 42ed3064
......@@ -15,7 +15,21 @@ import org.h2.message.Message;
*/
public class InDoubtTransaction {
public static final int IN_DOUBT = 0, COMMIT = 1, ROLLBACK = 2;
/**
* The transaction state meaning this transaction is not committed yet, but
* also not rolled back (in-doubt).
*/
public static final int IN_DOUBT = 0;
/**
* The transaction state meaning this transaction is committed.
*/
public static final int COMMIT = 1;
/**
* The transaction state meaning this transaction is rolled back.
*/
public static final int ROLLBACK = 2;
// TODO 2-phase-commit: document sql statements and metadata table
......@@ -26,7 +40,7 @@ public class InDoubtTransaction {
private int blocks;
private int state;
public InDoubtTransaction(LogFile log, int sessionId, int pos, String transaction, int blocks) {
InDoubtTransaction(LogFile log, int sessionId, int pos, String transaction, int blocks) {
this.log = log;
this.sessionId = sessionId;
this.pos = pos;
......@@ -35,6 +49,12 @@ public class InDoubtTransaction {
this.state = IN_DOUBT;
}
/**
* Change the state of this transaction.
* This will also update the log file.
*
* @param state the new state
*/
public void setState(int state) throws SQLException {
switch(state) {
case COMMIT:
......@@ -49,6 +69,11 @@ public class InDoubtTransaction {
this.state = state;
}
/**
* Get the state of this transaction as a text.
*
* @return the transaction state text
*/
public String getState() {
switch(state) {
case IN_DOUBT:
......@@ -62,6 +87,11 @@ public class InDoubtTransaction {
}
}
/**
* Get the name of the transaction.
*
* @return the transaction name
*/
public String getTransaction() {
return transaction;
}
......
h2/src/main/org/h2/log/LogFile.java
浏览文件 @ 42ed3064
......@@ -51,9 +51,13 @@ import org.h2.util.ObjectArray;
*/
public class LogFile {
private static final int BUFFER_SIZE = 8 * 1024;
/**
* The size of the smallest possible transaction log entry in bytes.
*/
public static final int BLOCK_SIZE = 16;
private static final int BUFFER_SIZE = 8 * 1024;
private LogSystem logSystem;
private Database database;
private int id;
......@@ -113,11 +117,16 @@ public class LogFile {
return new LogFile(log, id, fileNamePrefix);
}
/**
* Get the name of this transaction log file.
*
* @return the file name
*/
public String getFileName() {
return fileNamePrefix + "." + id + Constants.SUFFIX_LOG_FILE;
}
public int getId() {
int getId() {
return id;
}
......@@ -325,7 +334,7 @@ public class LogFile {
return true;
}
public void redoAllGoEnd() throws SQLException {
void redoAllGoEnd() throws SQLException {
boolean readOnly = logSystem.getDatabase().getReadOnly();
long length = file.length();
if (length <= FileStore.HEADER_LENGTH) {
......@@ -521,11 +530,11 @@ public class LogFile {
return pos;
}
public long getFileSize() throws SQLException {
long getFileSize() throws SQLException {
return file.getFilePointer();
}
public void sync() {
void sync() {
if (file != null) {
file.sync();
}
......
h2/src/main/org/h2/log/LogSystem.java
浏览文件 @ 42ed3064
......@@ -31,6 +31,9 @@ import org.h2.util.ObjectUtils;
*/
public class LogSystem {
/**
* This special log position means that the log entry has been written.
*/
public static final int LOG_WRITTEN = -1;
private Database database;
......@@ -53,6 +56,15 @@ public class LogSystem {
private boolean closed;
private String accessMode;
/**
* Create new transaction log object. This will not open or create files
* yet.
*
* @param database the database
* @param fileNamePrefix the name of the database file
* @param readOnly if the log should be opened in read-only mode
* @param accessMode the file access mode (r, rw, rws, rwd)
*/
public LogSystem(Database database, String fileNamePrefix, boolean readOnly, String accessMode) throws SQLException {
this.database = database;
this.readOnly = readOnly;
......@@ -65,14 +77,29 @@ public class LogSystem {
rowBuff = DataPage.create(database, Constants.DEFAULT_DATA_PAGE_SIZE);
}
/**
* Set the maximum log file size in megabytes.
*
* @param maxSize the new maximum log file size
*/
public void setMaxLogSize(long maxSize) {
this.maxLogSize = maxSize;
}
/**
* Get the maximum log file size.
*
* @return the maximum size
*/
public long getMaxLogSize() {
return maxLogSize;
}
/**
* Check if there are any in-doubt transactions.
*
* @return true if there are
*/
public boolean containsInDoubtTransactions() {
return inDoubtTransactions != null && inDoubtTransactions.size() > 0;
}
......@@ -132,6 +159,9 @@ public class LogSystem {
}
}
/**
* Close all log files.
*/
public void close() throws SQLException {
if (database == null) {
return;
......@@ -191,13 +221,17 @@ public class LogSystem {
undo.add(record);
}
public boolean recover() throws SQLException {
/**
* Roll back any uncommitted transactions if required, and apply committed
* changed to the data files.
*/
public void recover() throws SQLException {
if (database == null) {
return false;
return;
}
synchronized (database) {
if (closed) {
return false;
return;
}
undo = new ObjectArray();
for (int i = 0; i < activeLogs.size(); i++) {
......@@ -232,7 +266,7 @@ public class LogSystem {
if (!readOnly && fileChanged && !containsInDoubtTransactions()) {
checkpoint();
}
return fileChanged;
return;
}
}
......@@ -240,6 +274,9 @@ public class LogSystem {
l.close(deleteOldLogFilesAutomatically && keepFiles == 0);
}
/**
* Open all existing transaction log files and create a new one if required.
*/
public void open() throws SQLException {
String path = FileUtils.getParent(fileNamePrefix);
String[] list = FileUtils.listFiles(path);
......@@ -330,6 +367,11 @@ public class LogSystem {
state.inDoubtTransaction = new InDoubtTransaction(log, sessionId, pos, transaction, blocks);
}
/**
* Get the list of in-doubt transactions.
*
* @return the list
*/
public ObjectArray getInDoubtTransactions() {
return inDoubtTransactions;
}
......@@ -338,6 +380,12 @@ public class LogSystem {
sessions.remove(ObjectUtils.getInteger(sessionId));
}
/**
* Prepare a transaction.
*
* @param session the session
* @param transaction the name of the transaction
*/
public void prepareCommit(Session session, String transaction) throws SQLException {
if (database == null || readOnly) {
return;
......@@ -350,6 +398,11 @@ public class LogSystem {
}
}
/**
* Commit the current transaction of the given session.
*
* @param session the session
*/
public void commit(Session session) throws SQLException {
if (database == null || readOnly) {
return;
......@@ -363,6 +416,9 @@ public class LogSystem {
}
}
/**
* Flush all pending changes to the transaction log files.
*/
public void flush() throws SQLException {
if (database == null || readOnly) {
return;
......@@ -404,6 +460,13 @@ public class LogSystem {
}
}
/**
* Add an log entry to the last transaction log file.
*
* @param session the session
* @param file the file
* @param record the record to log
*/
public void add(Session session, DiskFile file, Record record) throws SQLException {
if (database == null) {
return;
......@@ -428,6 +491,10 @@ public class LogSystem {
}
}
/**
* Flush all data to the transaction log files as well as to the data files
* and and switch log files.
*/
public void checkpoint() throws SQLException {
if (readOnly || database == null) {
return;
......@@ -444,6 +511,11 @@ public class LogSystem {
}
}
/**
* Get all active log files.
*
* @return the list of log files
*/
public ObjectArray getActiveLogFiles() {
synchronized (database) {
ObjectArray list = new ObjectArray();
......@@ -483,14 +555,27 @@ public class LogSystem {
return rowBuff;
}
/**
* Enable or disable-flush-on-each-commit.
*
* @param b the new value
*/
public void setFlushOnEachCommit(boolean b) {
flushOnEachCommit = b;
}
/**
* Check if flush-on-each-commit is enabled.
*
* @return true if it is
*/
boolean getFlushOnEachCommit() {
return flushOnEachCommit;
}
/**
* Flush the transaction log file and sync the data to disk.
*/
public void sync() throws SQLException {
if (database == null || readOnly) {
return;
......@@ -503,6 +588,11 @@ public class LogSystem {
}
}
/**
* Enable or disable the transaction log
*
* @param disabled true if the log should be switched off
*/
public void setDisabled(boolean disabled) {
this.disabled = disabled;
}
......@@ -512,10 +602,18 @@ public class LogSystem {
file.addRedoLog(storage, recordId, blockCount, rec);
}
/**
* Write a log entry meaning the index summary is invalid.
*/
public void invalidateIndexSummary() throws SQLException {
currentLog.addSummary(false, null);
}
/**
* Increment or decrement the flag to keep (not delete) old log files.
*
* @param incrementDecrement (1 to increment, -1 to decrement)
*/
public synchronized void updateKeepFiles(int incrementDecrement) {
keepFiles += incrementDecrement;
}
......
h2/src/main/org/h2/log/SessionState.java
浏览文件 @ 42ed3064
......@@ -16,7 +16,7 @@ public class SessionState {
int lastCommitPos;
InDoubtTransaction inDoubtTransaction;
public boolean isCommitted(int logId, int pos) {
boolean isCommitted(int logId, int pos) {
if (logId != lastCommitLog) {
return lastCommitLog > logId;
}
......
h2/src/main/org/h2/log/UndoLog.java
浏览文件 @ 42ed3064
......@@ -30,11 +30,21 @@ public class UndoLog {
private DataPage rowBuff;
private int memoryUndo;
/**
* Create a new undo log for the given session.
*
* @param session the session
*/
public UndoLog(Session session) {
this.session = session;
this.database = session.getDatabase();
}
/**
* Get the number of active rows in this undo log.
*
* @return the number of rows
*/
public int size() {
if (SysProperties.CHECK && memoryUndo > records.size()) {
throw Message.getInternalError();
......@@ -42,6 +52,10 @@ public class UndoLog {
return records.size();
}
/**
* Clear the undo log. This method is called after the transaction is
* committed.
*/
public void clear() {
records.clear();
memoryUndo = 0;
......@@ -52,6 +66,11 @@ public class UndoLog {
}
}
/**
* Get the last record and remove it from the list of operations.
*
* @return the last record
*/
public UndoLogRecord getAndRemoveLast() throws SQLException {
int i = records.size() - 1;
UndoLogRecord entry = (UndoLogRecord) records.get(i);
......@@ -77,6 +96,11 @@ public class UndoLog {
return entry;
}
/**
* Append an undo log entry to the log.
*
* @param entry the entry
*/
public void add(UndoLogRecord entry) throws SQLException {
records.add(entry);
if (!entry.isStored()) {
......
h2/src/main/org/h2/log/UndoLogRecord.java
浏览文件 @ 42ed3064
......@@ -26,7 +26,17 @@ import org.h2.value.Value;
* An entry in a undo log.
*/
public class UndoLogRecord {
public static final short INSERT = 0, DELETE = 1;
/**
* Operation type meaning the row was inserted.
*/
public static final short INSERT = 0;
/**
* Operation type meaning the row was deleted.
*/
public static final short DELETE = 1;
private static final int IN_MEMORY = 0, STORED = 1, IN_MEMORY_READ_POS = 2;
private Table table;
private Row row;
......@@ -34,14 +44,13 @@ public class UndoLogRecord {
private short state;
private int filePos;
public boolean isStored() {
return state == STORED;
}
public boolean canStore() {
return table.getUniqueIndex() != null;
}
/**
* Create a new undo log record
*
* @param table the table
* @param op the operation type
* @param row the row that was deleted or inserted
*/
public UndoLogRecord(Table table, short op, Row row) {
this.table = table;
this.row = row;
......@@ -49,6 +58,20 @@ public class UndoLogRecord {
this.state = IN_MEMORY;
}
boolean isStored() {
return state == STORED;
}
boolean canStore() {
return table.getUniqueIndex() != null;
}
/**
* Un-do the operation. If the row was inserted before, it is deleted now,
* and vice versa.
*
* @param session the session
*/
public void undo(Session session) throws SQLException {
switch (operation) {
case INSERT:
......@@ -97,7 +120,7 @@ public class UndoLogRecord {
}
}
public void save(DataPage buff, FileStore file) throws SQLException {
void save(DataPage buff, FileStore file) throws SQLException {
buff.reset();
buff.writeInt(0);
buff.writeInt(operation);
......@@ -114,11 +137,11 @@ public class UndoLogRecord {
state = STORED;
}
public void seek(FileStore file) throws SQLException {
void seek(FileStore file) throws SQLException {
file.seek(filePos * Constants.FILE_BLOCK_SIZE);
}
public void load(DataPage buff, FileStore file, Session session) throws SQLException {
void load(DataPage buff, FileStore file, Session session) throws SQLException {
int min = Constants.FILE_BLOCK_SIZE;
seek(file);
buff.reset();
......@@ -144,10 +167,19 @@ public class UndoLogRecord {
state = IN_MEMORY_READ_POS;
}
/**
* Get the table.
*
* @return the table
*/
public Table getTable() {
return table;
}
/**
* This method is called after the operation was committed.
* It commits the change to the indexes.
*/
public void commit() throws SQLException {
ObjectArray list = table.getIndexes();
for (int i = 0; i < list.size(); i++) {
......@@ -156,6 +188,11 @@ public class UndoLogRecord {
}
}
/**
* Get the row that was deleted or inserted.
*
* @return the row
*/
public Row getRow() {
return row;
}
......
h2/src/main/org/h2/message/Trace.java
浏览文件 @ 42ed3064
......@@ -34,7 +34,6 @@ public class Trace {
public static final String SCHEMA = "schema";
public static final String DATABASE = "database";
public static final String SESSION = "session";
public static final String AGGREGATE = "aggregate";
Trace(TraceWriter traceWriter, String module) {
this.traceWriter = traceWriter;
......
h2/src/main/org/h2/message/TraceSystem.java
浏览文件 @ 42ed3064
......@@ -29,14 +29,50 @@ import org.h2.util.SmallLRUCache;
* the log file will be opened and closed again (which is slower).
*/
public class TraceSystem implements TraceWriter {
public static final int OFF = 0, ERROR = 1, INFO = 2, DEBUG = 3;
/**
* This trace level means nothing should be written.
*/
public static final int OFF = 0;
/**
* This trace level means only errors should be written.
*/
public static final int ERROR = 1;
/**
* This trace level means errors and informational messages should be
* written.
*/
public static final int INFO = 2;
/**
* This trace level means all type of messages should be written.
*/
public static final int DEBUG = 3;
/**
* This trace level means all type of messages should be written, but
* instead of using the trace file the messages should be written to SLF4J.
*/
public static final int ADAPTER = 4;
// max file size is currently 64 MB,
// and then there could be a .old file of the same size
private static final int DEFAULT_MAX_FILE_SIZE = 64 * 1024 * 1024;
/**
* The default level for system out trace messages.
*/
public static final int DEFAULT_TRACE_LEVEL_SYSTEM_OUT = OFF;
/**
* The default level for file trace messages.
*/
public static final int DEFAULT_TRACE_LEVEL_FILE = ERROR;
/**
* The default maximum trace file size. It is currently 64 MB. Additionally,
* there could be a .old file of the same size.
*/
private static final int DEFAULT_MAX_FILE_SIZE = 64 * 1024 * 1024;
private static final int CHECK_FILE_TIME = 4000;
private int levelSystemOut = DEFAULT_TRACE_LEVEL_SYSTEM_OUT;
private int levelFile = DEFAULT_TRACE_LEVEL_FILE;
......@@ -54,17 +90,12 @@ public class TraceSystem implements TraceWriter {
private boolean writingErrorLogged;
private TraceWriter writer = this;
public static void traceThrowable(Throwable e) {
PrintWriter writer = DriverManager.getLogWriter();
if (writer != null) {
e.printStackTrace(writer);
}
}
public void setManualEnabling(boolean value) {
this.manualEnabling = value;
}
/**
* Create a new trace system object.
*
* @param fileName the file name
* @param init if the trace system should be initialized
*/
public TraceSystem(String fileName, boolean init) {
this.fileName = fileName;
traces = new SmallLRUCache(100);
......@@ -78,6 +109,34 @@ public class TraceSystem implements TraceWriter {
}
}
/**
* Write the exception to the driver manager log writer if configured.
*
* @param e the exception
*/
public static void traceThrowable(Throwable e) {
PrintWriter writer = DriverManager.getLogWriter();
if (writer != null) {
e.printStackTrace(writer);
}
}
/**
* Allow to manually enable the trace option by placing a specially named
* file in the right folder.
*
* @param value the new value
*/
public void setManualEnabling(boolean value) {
this.manualEnabling = value;
}
/**
* Get or create a trace object for this module.
*
* @param module the module name
* @return the trace object
*/
public synchronized Trace getTrace(String module) {
Trace t = (Trace) traces.get(module);
if (t == null) {
......@@ -92,18 +151,38 @@ public class TraceSystem implements TraceWriter {
return level <= max;
}
/**
* Set the trace file name.
*
* @param name the file name
*/
public void setFileName(String name) {
this.fileName = name;
}
/**
* Set the maximum trace file size in bytes.
*
* @param max the maximum size
*/
public void setMaxFileSize(int max) {
this.maxFileSize = max;
}
/**
* Set the trace level to use for System.out
*
* @param level the new level
*/
public void setLevelSystemOut(int level) {
levelSystemOut = level;
}
/**
* Set the file trace level.
*
* @param level the new level
*/
public void setLevelFile(int level) {
if (level == ADAPTER) {
String adapterClass = "org.h2.message.TraceWriterAdapter";
......@@ -255,6 +334,11 @@ public class TraceSystem implements TraceWriter {
}
}
/**
* Close the writers, and the files if required. It is still possible to
* write after closing, however after each write the file is closed again
* (slowing down tracing).
*/
public void close() {
closeWriter();
closed = true;
......
h2/src/test/org/h2/test/TestAll.java
浏览文件 @ 42ed3064
......@@ -160,18 +160,23 @@ java org.h2.test.TestAll timer
/*
jazoon
support CLOB in fulltext index
upload and test javadoc/index.html
test clob fulltext index (lucene and native).
download PostgreSQL docs
in help.csv, use complete examples for functions; add a test case
upload and test javadoc/index.html
improve javadocs
option to write complete page right after checkpoint
upload jazoon
test case for out of memory (try to corrupt the database using out of memory)
analyzer configuration option for the fulltext search
......@@ -227,6 +232,7 @@ Roadmap:
converted to primary key columns.
PostgreSQL compatibility: support for BOOL_OR and BOOL_AND
aggregate functions.
The fulltext search did not support CLOB data types. Fixed.
*/
if (args.length > 0) {
......
h2/src/test/org/h2/test/db/TestFullText.java
浏览文件 @ 42ed3064
......@@ -23,12 +23,16 @@ public class TestFullText extends TestBase {
if (config.memory) {
return;
}
test(false);
test(false, "VARCHAR");
int test;
test(false, "VARCHAR");
testPerformance(false);
String luceneFullTextClassName = "org.h2.fulltext.FullTextLucene";
try {
Class.forName(luceneFullTextClassName);
test(true);
test(true, "VARCHAR");
int test2;
test(true, "VARCHAR");
testPerformance(true);
} catch (ClassNotFoundException e) {
println("Class not found, not tested: " + luceneFullTextClassName);
......@@ -80,7 +84,7 @@ public class TestFullText extends TestBase {
conn.close();
}
private void test(boolean lucene) throws Exception {
private void test(boolean lucene, String dataType) throws Exception {
deleteDb("fullText");
Connection conn = getConnection("fullText");
String prefix = lucene ? "FTL_" : "FT_";
......@@ -89,7 +93,7 @@ public class TestFullText extends TestBase {
stat.execute("CREATE ALIAS IF NOT EXISTS " + prefix + "INIT FOR \"org.h2.fulltext." + className + ".init\"");
stat.execute("CALL " + prefix + "INIT()");
stat.execute("DROP TABLE IF EXISTS TEST");
stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR)");
stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME " + dataType + ")");
stat.execute("INSERT INTO TEST VALUES(1, 'Hello World')");
stat.execute("CALL " + prefix + "CREATE_INDEX('PUBLIC', 'TEST', NULL)");
ResultSet rs;
......
h2/src/tools/org/h2/build/doc/dictionary.txt
浏览文件 @ 42ed3064
......@@ -511,4 +511,6 @@ subpackages slowed deactivate throttled noindex expired arizona export
intentional knowing jcl plug facade deployment logback confusion visited
pickle associate subtraction negation multiplication visitors sharp connector
derbynet ado happy derbyclient unspecified federated sysadmin lengths doing
gives clunky
gives clunky cooperative paged conflicts ontology freely regards standards
placing refer informational unlocks
h2/src/tools/org/h2/build/doclet/Doclet.java
浏览文件 @ 42ed3064
......@@ -375,29 +375,28 @@ public class Doclet {
private boolean doesOverride(MethodDoc method) {
ClassDoc clazz = method.containingClass();
ClassDoc[] ifs = clazz.interfaces();
int pc = method.parameters().length;
String name = method.name();
for (int i = 0;; i++) {
ClassDoc c;
if (i < ifs.length) {
c = ifs[i];
} else {
clazz = clazz.superclass();
if (clazz == null) {
break;
}
c = clazz;
int parameterCount = method.parameters().length;
return foundMethod(clazz, false, method.name(), parameterCount);
}
MethodDoc[] ms = c.methods();
private boolean foundMethod(ClassDoc clazz, boolean include, String methodName, int parameterCount) {
if (include) {
MethodDoc[] ms = clazz.methods();
for (int j = 0; j < ms.length; j++) {
MethodDoc m = ms[j];
if (m.name().equals(name) && m.parameters().length == pc) {
if (m.name().equals(methodName) && m.parameters().length == parameterCount) {
return true;
}
}
}
return false;
ClassDoc[] ifs = clazz.interfaces();
for (int i = 0; i < ifs.length; i++) {
if (foundMethod(ifs[i], true, methodName, parameterCount)) {
return true;
}
}
clazz = clazz.superclass();
return clazz != null && foundMethod(clazz, true, methodName, parameterCount);
}
private static String getFirstSentence(Tag[] tags) {
......
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