@@ -54,7 +54,7 @@ Of course, patches are always welcome, but are not always applied as is. Patches
</li><li>Change LOB mechanism (less files, keep index of lob files, point to files and row, delete unused files earlier, maybe bundle files into a tar file)
</li><li>Clustering: recovery needs to becomes fully automatic. Global write lock feature.
</li><li>Option for Java functions: [DETERMINISTIC] FOR ...
The fulltext search documentation has been improved.
@changelog_1003_li
H2 Console: Columns are now listed for up to 500 tables instead of 100.
ARRAY_GET returned the wrong data type (ARRAY). Now it returns VARCHAR.
@changelog_1004_li
H2 Console: Cmd+Enter executes the current statement.
Natural join: the joined columns are not repeated any more when using SELECT *.
@changelog_1005_li
JaQu: the maximum length of a column can now be defined using maxLength. For an example, see Product.java (maxLength(category, 255)).
User defined aggregate functions: the method getType expected internal data types instead of SQL types.
@changelog_1006_li
R&\#305;dvan A&\#287;ar has completed the Turkish translation of the H2 Console. Thanks a lot!
User defined aggregate functions did not work if there was no group by expression.
@changelog_1007_h2
Version 1.1.104 (2008-11-28)
@changelog_1007_li
MySQL compatibility: support for := assignment as in @sum:=@sum+x
@changelog_1008_li
New meta data column INFORMATION_SCHEMA.TABLES.LAST_MODIFICATION to get the table modification counter.
INSERT INTO TEST(SELECT * FROM TEST) is now supported.
@changelog_1009_li
If a query that was used like a table contained group by and was ordered by an expression that is not in the column list, an exception was thrown.
Each session threw an invisible exception when garbage collected.
@changelog_1010_li
JaQu: tables are now auto-created when running a query.
Foreign key constraints that refer to a quoted column did not work.
@changelog_1011_li
The optimizer had problems with function tables (for example CSVREAD and FTL_SEARCH). A new system property h2.estimatedFunctionTableRows (default 1000) defines how many rows can be expected in the table.
New meta data column INFORMATION_SCHEMA.TABLES.LAST_MODIFICATION to get the table modification counter.
@changelog_1012_li
The function SUM could overflow when using large values. It returns now a data type that is safe.
Shell: line comments didn't work correctly.
@changelog_1013_li
The function AVG could overflow when using large values. Fixed.
H2 Console: Columns are now listed for up to 500 tables instead of 100.
@changelog_1014_li
The emergency reserve file has been removed. It didn't provide an appropriate solution for the problem. It is still possible for an application to detect and deal with the low disk space problem (deleting temporary files for example) using DatabaseEventListener.diskSpaceIsLow, but this method is now always called with stillAvailable=0.
H2 Console: Cmd+Enter executes the current statement, Alt+Space for autocomplete.
@changelog_1015_li
Build: JAVA_HOME is now automatically detected on Mac OS X.
JaQu: the maximum length of a column can now be defined using maxLength. For an example, see Product.java (maxLength(category, 255)).
@changelog_1016_li
R&\#305;dvan A&\#287;ar has completed the Turkish translation of the H2 Console. Thanks a lot!
@changelog_1017_h2
Version 1.1.104 (2008-11-28)
@changelog_1018_li
If a query that was used like a table contained group by and was ordered by an expression that is not in the column list, an exception was thrown.
@changelog_1019_li
JaQu: tables are now auto-created when running a query.
@changelog_1020_li
The optimizer had problems with function tables (for example CSVREAD and FTL_SEARCH). A new system property h2.estimatedFunctionTableRows (default 1000) defines how many rows can be expected in the table.
@changelog_1021_li
The function SUM could overflow when using large values. It returns now a data type that is safe.
@changelog_1022_li
The function AVG could overflow when using large values. Fixed.
@changelog_1023_li
The emergency reserve file has been removed. It didn't provide an appropriate solution for the problem. It is still possible for an application to detect and deal with the low disk space problem (deleting temporary files for example) using DatabaseEventListener.diskSpaceIsLow, but this method is now always called with stillAvailable=0.
@changelog_1024_li
Build: JAVA_HOME is now automatically detected on Mac OS X.
@changelog_1025_li
Testing for local connections was very slow on some systems.
@changelog_1017_li
@changelog_1026_li
The cache memory usage calculation is more conservative.
@changelog_1018_li
@changelog_1027_li
Allocating space got slower and slower the larger the database.
@changelog_1019_li
@changelog_1028_li
ALTER TABLE ALTER COLUMN could throw the wrong exception in the last version (Table not found).
@changelog_1020_li
@changelog_1029_li
Updatable result sets: the key columns can now be updated.
@changelog_1021_li
@changelog_1030_li
The H2DatabaseProvider for ActiveObjects is now included in the tools section.
@changelog_1022_li
@changelog_1031_li
The H2Platform for Oracle Toplink Essential has been improved a bit.
@changelog_1023_li
@changelog_1032_li
The Windows service to start H2 didn't work in version 1.1.
@changelog_1024_li
@changelog_1033_li
File systems with a maximum file size (for example FAT) are now supported using the file prefix 'split:'. In this case the files are split in parts of 1 GB. Example URL: jdbc:h2:split:~/db/test. If you want to split into parts of 1 MB, use jdbc:h2:split:20:~/db/test (the part size is 1 << x, the default is 30 meaning 1 GB).
@changelog_1025_li
@changelog_1034_li
The database now tries to detect if the classloader or virtual machine has almost shut down by checking if static final variables are set to null. This should help reduce exceptions when stopping the web application.
@changelog_1026_li
@changelog_1035_li
Compatibility for MS SQL Server DATEDIFF(YYYY, .., ..)
@changelog_1027_li
@changelog_1036_li
ResultSet.getObject for CLOB or BLOB will return a java.sql.Clob / java.sql.Blob object instead of a java.io.Reader / java.io.InputStream as in version 1.0. This behavior can be changed using the system property h2.returnLobObjects (true by default for version 1.1).
@changelog_1028_li
@changelog_1037_li
The interface CloseListener has a new method 'remove' that is called when the trigger is dropped.
@changelog_1029_li
@changelog_1038_li
Fulltext search: there was a memory leak when creating and dropping fulltext indexes in a loop.
@changelog_1030_h2
@changelog_1039_h2
Version 1.1.103 (2008-11-07)
@changelog_1031_li
@changelog_1040_li
Could not order by a formula when the formula was in the group by list but not in the select list.
@changelog_1032_li
@changelog_1041_li
Date values that match the daylight saving time end were not allowed in times zones were the daylight saving time ends at midnight, for years larger than 2037. Example: timezone Brasilia, date 2042-10-12. This is a problem of Java, however a workaround is implemented in H2 that solves most problems (except the problems of java.util.Date itself).
@changelog_1033_li
@changelog_1042_li
ALTER TABLE used a lot of memory when using multi-version concurrency.
@changelog_1034_li
@changelog_1043_li
Referential integrity for in-memory databases didn't work in some cases in version 1.1.102.
@changelog_1035_li
@changelog_1044_li
New column INFORMATION_SCHEMA.COLUMNS.SEQUENCE_NAME to get the name of the sequence for auto-increment columns.
@changelog_1036_li
@changelog_1045_li
Aliases for built-in data types (such as MEDIUMBLOB which is an alias for BLOB) can now be re-mapped to another data type using CREATE DOMAIN. However main built-in data types (such as INTEGER) can not be re-mapped.
@changelog_1037_li
@changelog_1046_li
The Japanese translation has been completed by Masahiro Ikemoto. Thanks a lot!
@changelog_1038_li
@changelog_1047_li
Improved PostgreSQL compatibility for NEXTVAL and CURRVAL.
@changelog_1039_li
@changelog_1048_li
Less heap memory is needed when multiple databases are open at the same time: The memory reserve (used to rollback after out of memory) is now global and no longer allocated for each database separately.
@changelog_1040_li
@changelog_1049_li
New system property h2.browser to set the browser to use.
@changelog_1041_li
@changelog_1050_li
To start the browser, java.awt.Desktop.browse is now used if available.
@changelog_1042_h2
@changelog_1051_h2
Version 1.1.102 (2008-10-24)
@changelog_1043_li
@changelog_1052_li
The French translation of the H2 Console has been improved by Olivier Parent. Thanks a lot!
@changelog_1044_li
@changelog_1053_li
There was a memory leak when creating and dropping tables and indexes in a loop (persistent database only).
@changelog_1045_li
@changelog_1054_li
SET LOG 2 was not effective if executed after opening the database.
@changelog_1046_li
@changelog_1055_li
Translating the H2 Console is now simpler.
@changelog_1047_li
@changelog_1056_li
Common exception (error code 23*) are no longer written to the .trace.db file by default.
@changelog_1048_li
@changelog_1057_li
In-memory databases don't write LOBs to files any longer.
@changelog_1049_li
@changelog_1058_li
Self referencing constraints didn't restrict deleting rows that reference itself if there is another row that references it.
@changelog_1050_li
@changelog_1059_li
ResultSetMetaData.getColumnName now returns the alias name except for columns.
@changelog_1051_li
@changelog_1060_li
Temporary files are now deleted when the database is closed, even if they were not garbage collected so far.
@changelog_1052_h2
@changelog_1061_h2
Version 1.1.101 (2008-10-17)
@changelog_1053_li
@changelog_1062_li
Errors with code 42000 - 42999 are no longer written to the trace file by default.
@changelog_1054_li
@changelog_1063_li
Queries with more than 10 tables are now faster.
@changelog_1055_li
@changelog_1064_li
Opening a connection with AUTO_SERVER=TRUE is now fast when the database is already open in another process (less than 0.01 seconds instead of 2 seconds).
@changelog_1056_li
@changelog_1065_li
IF [NOT] EXISTS is supported for named constraints in ALTER TABLE ... ADD/DROP CONSTRAINT.
@changelog_1057_li
@changelog_1066_li
The error messages have been translated to Spanish by Dario V. Fassi. Thanks a lot!
@changelog_1058_li
@changelog_1067_li
Linked tables: the automatic connection sharing didn't work. Actually the system property h2.shareLinkedConnections was working in the opposite direction: it was disabled when set to true. Now it works as expected.
@changelog_1059_li
@changelog_1068_li
Opening large database is now faster.
@changelog_1060_li
@changelog_1069_li
New system property h2.socketConnectTimeout, the timeout in milliseconds to connect to a server. The default is 2000 (2 seconds).
@changelog_1061_li
@changelog_1070_li
The wrong parameters were bound to subqueries with parameters, specially when using IN(SELECT ...) and IN(...).
@changelog_1062_li
@changelog_1071_li
Unset parameters were not detected when the query was re-compiled.
@changelog_1063_li
@changelog_1072_li
New functions ISO_YEAR, ISO_WEEK, ISO_DAY_OF_WEEK. Thanks a lot to Robert Rathsack for implementing those!
@changelog_1064_li
@changelog_1073_li
The date functions DAYOFYEAR, DAYOFMONTH, DAYOFWEEK are now called DAY_OF_YEAR, DAY_OF_MONTH, DAY_OF_WEEK (the old names still work).
@changelog_1065_li
@changelog_1074_li
An out of memory error while deleting or updating many rows could result in a strange exception.
@changelog_1066_li
@changelog_1075_li
Linked tables: compatibility with MS SQL Server has been improved.
@changelog_1067_li
@changelog_1076_li
Renaming tables that have foreign keys with cascade didn't work correctly.
@changelog_1068_li
@changelog_1077_li
The auto-reconnect feature didn't work when using the auto-server mode. Fixed.
@changelog_1069_li
@changelog_1078_li
Fulltext search: new method FT_DROP_INDEX.
@changelog_1070_li
@changelog_1079_li
The optimization to group using an index didn't work in some cases in version 1.1 (see also system property h2.optimizeGroupSorted).
@changelog_1071_li
@changelog_1080_li
OSGi meta data is included in the manifest file. An OSGi BundleActivator is included: it loads the database driver when starting the bundle, and unloads it when stopping the bundle.
@changelog_1072_li
@changelog_1081_li
The default value for MAX_MEMORY_UNDO is now 50000.
@changelog_1073_li
@changelog_1082_li
For alias columns, ResultSetMetaData.getTableName() and getColumnName() now return the real table and column name in the default mode.
@changelog_1074_li
@changelog_1083_li
In SQL scripts created with SCRIPT TO, schemas are now only created if they don't exist yet.
@changelog_1075_li
@changelog_1084_li
After re-connecting to a database, the database event listener (if set) is informed about it.
@changelog_1076_li
@changelog_1085_li
Local temporary tables now support indexes. Thanks a lot to Matt Roy!
@changelog_1077_li
@changelog_1086_li
RUNSCRIPT no longer uses a temporary file.
@changelog_1078_li
@changelog_1087_li
New system table INFORMATION_SCHEMA.SESSION_STATE containing the SQL statements that make up the session state. The list currently contains variables (SET @..) and local temporary tables (without data).
@changelog_1079_li
@changelog_1088_li
After an automatic re-connect, part of the session state stays (the part that is stored in the SESSION_STATE table).
@changelog_1080_li
@changelog_1089_li
The build didn't work if the directory temp didn't exist before.
@changelog_1081_li
@changelog_1090_li
New system property h2.maxReconnect (default 3) to limit the number of re-connects for the same SQL statement (this is usually only important for SHUTDOWN).
@changelog_1082_li
@changelog_1091_li
WHERE .. IN (SELECT ...) could throw a NullPointerException.
@changelog_1083_li
@changelog_1092_li
Improved Glassfish / Toplink support in H2Platform thanks to Marcio Borges from Brazil. Thanks a lot!
@changelog_1084_h2
@changelog_1093_h2
Version 1.1.100 (2008-10-04)
@changelog_1085_li
@changelog_1094_li
In version 1.1, the following system properties are now enabled by default: h2.lobFilesInDirectories, h2.optimizeGroupSorted, h2.optimizeInJoin, h2.shareLinkedConnections
@changelog_1086_li
@changelog_1095_li
The H2 Console tool now works with the JDBC-ODBC bridge.
@changelog_1087_li
@changelog_1096_li
The H2 Console tool now supports command line options to start things separately.
@changelog_1088_li
@changelog_1097_li
Large objects did not work for in-memory databases in server mode in Linux.
@changelog_1089_li
@changelog_1098_li
Connections from a local address other than 'localhost' were not allowed if remote connections were disabled. This was always a problem, but only got visible in the last release because the server no longer connects to 'localhost' if networked.
@changelog_1090_li
@changelog_1099_li
The h2console.war can now be built using the Java build.
@changelog_1091_li
@changelog_1100_li
By default, databases are shared in the same process. For read-only databases this causes unnecessary synchronization, but safes memory. If you want that each connection opens its own database, append ;OPEN_NEW=TRUE to the database URL.
@changelog_1092_li
@changelog_1101_li
New auto-reconnect feature will cause the JDBC driver to reconnect to the database if the connection is lost. To enable, append ;AUTO_RECONNECT=TRUE to the database URL. This is specially helpful when using AUTO_SERVER. AUTO_SERVER automatically uses auto-reconnect.
@changelog_1093_li
@changelog_1102_li
CreateCluster: the property 'serverlist' is now called 'serverList'.
@changelog_1094_li
@changelog_1103_li
The ConvertTraceFile tool could not parse some files because the trace mechanism did not encode prepared statement parameters.
@changelog_1095_li
@changelog_1104_li
Databases names can now be one character long (the minimum size used to be 2 characters).
@changelog_1096_h2
@changelog_1105_h2
Version 1.0.79 (2008-09-26)
@changelog_1097_li
@changelog_1106_li
Linked tables that point to the same database can now share the connection within the same database. Access to the same connection is serialized. To enable this feature, set the system property h2.shareLinkedConnections to true.
@changelog_1098_li
@changelog_1107_li
Multiple processes can now access the same database without having to explicitly start the server. To do that, append ;AUTO_SERVER=TRUE to the database URL. In this case, the server is started automatically if the connection is in embedded mode, and the server mode is used if a server is running. If the process that opened the first connection is closed, the other client need to reconnect (there is no automatic re-connect so far). Remote connections are allowed, but only to this database.
@changelog_1099_li
@changelog_1108_li
The server tool now displays the correct IP address if networked.
@changelog_1100_li
@changelog_1109_li
Can now start a TCP server with port 0 (automatically select a port).
@changelog_1101_li
@changelog_1110_li
Result sets with just a unique index can now be updated (previously a primary key was required).
@changelog_1102_li
@changelog_1111_li
LINKED TABLE: the schema name can now be set. When multiple tables exist in different schema, and the schema name is not set, an exception is thrown.
@changelog_1103_li
@changelog_1112_li
LINKED TABLE: worked around a bug in Oracle with the CHAR data type.
@changelog_1104_li
@changelog_1113_li
Faster hash code calculation for large binary arrays.
@changelog_1105_li
@changelog_1114_li
Faster storage re-use algorithm thanks to Greg Dhuse from cleversafe.com.
@changelog_1106_li
@changelog_1115_li
The database supports the SHOW command for better MySQL and PostgreSQL compatibility.
@changelog_1107_li
@changelog_1116_li
The H2 Console now abbreviates large texts in results.
@changelog_1108_li
@changelog_1117_li
Multiple UNION queries could not be used in derived tables.
@changelog_1109_li
@changelog_1118_li
Linked tables can now be read-only.
@changelog_1110_li
@changelog_1119_li
Temporary linked tables are now supported.
@changelog_1111_li
@changelog_1120_li
It was possible to create tables in read-only databases.
@changelog_1112_li
@changelog_1121_li
SET SCHEMA_SEARCH_PATH is now documented.
@changelog_1113_li
@changelog_1122_li
SET SCHEMA did not work for views.
@changelog_1114_li
@changelog_1123_li
Row level locking for MVCC is now enabled. The exception 'Concurrent update in table ...' is still thrown, but only after the lock timeout.
@changelog_1115_li
@changelog_1124_li
The maximum log file size setting was ignored for large databases.
@changelog_1116_li
@changelog_1125_li
Multi-Version Concurrency (MVCC) may no longer be used when using the multi-threaded kernel feature (MULTI_THREADED). An exception is thrown when trying to connect with both settings. Additional synchronization is required before those features can be used together.
@changelog_1117_li
@changelog_1126_li
The data type JAVA_OBJECT could not be used in updatable result sets.
@changelog_1118_li
@changelog_1127_li
The system property h2.optimizeInJoin did not work correctly.
@changelog_1119_li
@changelog_1128_li
Conditions such as ID=? AND ID>? were slow.
@changelog_1120_h2
@changelog_1129_h2
Version 1.0.78 (2008-08-28)
@changelog_1121_li
@changelog_1130_li
The documentation no longer uses a frameset (except the Javadocs).
@changelog_1122_li
@changelog_1131_li
When using DB_CLOSE_DELAY, sometimes a NullPointerException is thrown when the database is opened almost at the same time as it is closed automatically. Thanks a lot to Dmitry Pekar for finding this!
@changelog_1123_li
@changelog_1132_li
Java methods with variable number of parameters can now be used (for Java 1.5 or newer).
@changelog_1124_li
@changelog_1133_li
The Japanese translation has been improved by Masahiro Ikemoto. Thanks a lot!
@changelog_1125_li
@changelog_1134_li
The H2 Console replaced an empty user name with a single space.
@changelog_1126_li
@changelog_1135_li
The build target 'build jarSmall' now includes the embedded database.
@changelog_1127_li
@changelog_1136_li
JdbcDataSource now keeps the password in a char array where possible.
@changelog_1128_li
@changelog_1137_li
ResultSet.absolute did not always work with large result sets.
@changelog_1129_li
@changelog_1138_li
Column aliases can now be used in GROUP BY and HAVING.
@changelog_1130_li
@changelog_1139_li
Jason Brittain has contributed MySQL date functions. Thanks a lot! They are not in the h2.jar file currently, but in src/tools/org/h2/mode/FunctionsMySQL.java. To install, add this class to the classpath and call FunctionsMySQL.register(conn) in the Java code.
@changelog_1131_h2
@changelog_1140_h2
Version 1.0.77 (2008-08-16)
@changelog_1132_li
@changelog_1141_li
JaQu is now using prepared statements and supports Date, Time, Timestamp.
@changelog_1133_li
@changelog_1142_li
When using remote in-memory databases, large LOB objects did not work.
@changelog_1134_li
@changelog_1143_li
Timestamp columns such as TIMESTAMP(6) were not compatible to other database.
@changelog_1135_li
@changelog_1144_li
Opening a large database was slow if there was a problem opening the previous time.
@changelog_1136_li
@changelog_1145_li
NOT IN(SELECT ...) was incorrect if the subquery returns no rows.
@changelog_1137_li
@changelog_1146_li
CREATE TABLE AS SELECT did not work correctly in the multi-version concurrency mode.
@changelog_1138_li
@changelog_1147_li
Support a comma before closing a list, as in: create table test(id int,)
@changelog_1139_li
@changelog_1148_li
MySQL compatibility: linked tables had lower case column names on some systems.
@changelog_1140_li
@changelog_1149_li
DB2 compatibility: the DB2 fetch-first-clause is supported.
@changelog_1141_li
@changelog_1150_li
Oracle compatibility: old style outer join syntax using (+) did work correctly sometimes.
@changelog_1142_li
@changelog_1151_li
ResultSet.setFetchSize is now supported.
@changelog_1143_li
@changelog_1152_li
It has been reported that when using Install4j on some Linux systems and enabling the 'pack200' option, the h2.jar becomes corrupted by the install process, causing application failure. A workaround is to add an empty file h2.jar.nopack next to the h2.jar file. The reason for this problem is not known.
@changelog_1144_h2
@changelog_1153_h2
Version 1.0.76 (2008-07-27)
@changelog_1145_li
@changelog_1154_li
The comment of a domain (user defined data type) is now used as the default column comment when creating a column with this domain.
@changelog_1146_li
@changelog_1155_li
Invalid database names are now detected and a better error message is thrown.
@changelog_1147_li
@changelog_1156_li
ResultSetMetaData.getColumnClassName now returns the correct class name for BLOB and CLOB.
@changelog_1148_li
@changelog_1157_li
Fixed the Oracle mode: Oracle allows multiple rows only where all columns of the unique index are NULL.
@changelog_1149_li
@changelog_1158_li
There is a problem with Hibernate when using Boolean columns. A patch for Hibernate has been submitted at http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401
@changelog_1150_li
@changelog_1159_li
ORDER BY on tableName.columnName didn't work correctly if the column name was also used as an alias.
@changelog_1151_li
@changelog_1160_li
H2 Console: The progress display when opening a database has been improved.
@changelog_1152_li
@changelog_1161_li
The error message when the server doesn't start has been improved.
@changelog_1153_li
@changelog_1162_li
Key values can now be changed in updatable result sets.
@changelog_1154_li
@changelog_1163_li
Changes in updatable result sets are now visible even when resetting the result set.
@changelog_1155_li
@changelog_1164_li
Temporary files were sometimes deleted too late when executing large insert, update, or delete operations.
@changelog_1156_li
@changelog_1165_li
The database file was growing after deleting many rows, and after large update operations.
@changelog_1157_h2
@changelog_1166_h2
Version 1.0.75 (2008-07-14)
@changelog_1158_li
@changelog_1167_li
Multi version concurrency (MVCC): when a row was updated or deleted, but this change was rolled back, the row was not visible by other sessions if no index was used to access it. Fixed.
@changelog_1159_li
@changelog_1168_li
Views with multiple joined tables (where one was an outer join) couldn't be used in some cases. Fixed.
@changelog_1160_li
@changelog_1169_li
The CSVREAD method did not process NULL correctly when using a whitespace field separator.
@changelog_1161_li
@changelog_1170_li
Fixed the Oracle mode: Oracle allows multiple rows with NULL in a unique index.
@changelog_1162_li
@changelog_1171_li
Running out of memory could result in incomplete transactions or corrupted databases. Fixed.
@changelog_1163_li
@changelog_1172_li
When using order by in a query that uses the same table multiple times, the order could be incorrect. Fixed.
@changelog_1164_li
@changelog_1173_li
Referential constraint checking improvement: now the constraint is only checked if the key column values change.
@changelog_1165_li
@changelog_1174_li
Some database metadata calls returned the wrong data type for DATA_TYPE columns.
@changelog_1166_li
@changelog_1175_li
The Lucene fulltext index was empty when opening a database with fulltext index enabled, and re-indexing it didn't work. Fixed.
@changelog_1167_li
@changelog_1176_li
The character '$' could not be used in identifier names (table name, column names and so on). Fixed.
@changelog_1168_li
@changelog_1177_li
The new method org.h2.tools.Server.startWebServer(conn) starts the H2 Console to inspect a database while debugging.
@changelog_1169_li
@changelog_1178_li
Stopping a WebServer didn't always work. Fixed.
@changelog_1170_h2
@changelog_1179_h2
Version 1.0.74 (2008-06-21)
@changelog_1171_li
@changelog_1180_li
Work on row level locking has been started (but there is nothing usable yet).
@changelog_1172_li
@changelog_1181_li
JaQu (Java Query), a tool similar to LINQ (Language Integrated Query; from Microsoft) is now included under src/tools/org/h2/jaqu. A small sample application is included under src/test/org/h2/test/jaqu.
@changelog_1173_li
@changelog_1182_li
The source code is now switched to Java 1.6 by default. To switch back to Java 1.4, run 'build compile'. The h2.jar file is still Java 1.4.
@changelog_1174_li
@changelog_1183_li
The ChangePassword tool is now called ChangeFileEncryption.
@changelog_1175_li
@changelog_1184_li
It is no longer allowed to create columns with the data type NULL. Also, it is no longer allowed to convert a column to the data type NULL. This was possible before but caused data loss.
@changelog_1176_li
@changelog_1185_li
When using computed columns or default values with a different data type than the column data type, a class cast exception could occur. Fixed.
@changelog_1177_li
@changelog_1186_li
Opening databases larger than 1 GB was sometimes very slow if a lot of data was deleted previously. Fixed.
@changelog_1178_li
@changelog_1187_li
RUNSCRIPT could throw a NullPointerException if the script name was an expression.
@changelog_1179_li
@changelog_1188_li
Improved compatibility. New compatibility modes for Oracle and Derby. New compatibility flag uniqueIndexNullDistinct to only allow one row with 'NULL' in a unique index. This flag is enabled for Derby, Oracle, MSSQLServer, and HSQLDB.
@changelog_1180_li
@changelog_1189_li
Linked tables: To view the statements that are executed against the target table, set the trace level to 3.
@changelog_1181_li
@changelog_1190_li
RunScript tool: new options to show and check the results of queries.
@changelog_1182_li
@changelog_1191_li
Deadlocks are now detected. One transaction is rolled back automatically.
@changelog_1183_li
@changelog_1192_li
The Lucene fulltext index was always re-created when opening a database with fulltext index enabled.
@changelog_1184_li
@changelog_1193_li
Support for overloaded Java methods. A user defined function can now be bound to multiple Java methods, if the Java methods have the same name but a different number of parameters. Thanks to Gary Tong for providing a patch!
@changelog_1185_h2
@changelog_1194_h2
Version 1.0.73 (2008-05-31)
@changelog_1186_li
@changelog_1195_li
ParameterMetaData now returns the right data type for most conditions, as in WHERE ID=?.
@changelog_1187_li
@changelog_1196_li
The table SYSTEM_RANGE now supports expressions and parameters.
@changelog_1188_li
@changelog_1197_li
New column INFORMATION_SCHEMA.CONSTRAINTS.UNIQUE_INDEX_NAME that contains the name of the unique index used to enforce this constraint, if there is such an index.
@changelog_1189_li
@changelog_1198_li
SET QUERY_TIMEOUT and Statement.setQueryTimeout no longer commits a transaction. The same applies to SET @VARIABLE, SET LOCK_TIMEOUT, SET TRACE_LEVEL_*, SET THROTTLE, and SET PATH.
@changelog_1190_li
@changelog_1199_li
The SCRIPT command does now emit IF NOT EXISTS for CREATE ROLE.
@changelog_1191_li
@changelog_1200_li
MySQL compatibility: auto_increment column are no longer automatically converted to primary key columns.
@changelog_1192_li
@changelog_1201_li
PostgreSQL compatibility: support for BOOL_OR and BOOL_AND aggregate functions.
@changelog_1193_li
@changelog_1202_li
Negative scale values for DECIMAL or NUMBER columns are now supported in regular tables and in linked tables.
@changelog_1194_li
@changelog_1203_li
A role or right can now be granted or revoked multiple times without getting an exception.
@changelog_1195_li
@changelog_1204_li
Infinite numbers in SQL scripts are listed as POWER(0, -1)), negative infinite as (-POWER(0, -1)), and NaN (not a number) as SQRT(-1).
@changelog_1196_li
@changelog_1205_li
The special double and float values 'NaN' (not a number) did not work correctly when sorting or comparing.
@changelog_1197_li
@changelog_1206_li
The fulltext search did not support CLOB data types.
@changelog_1198_li
@changelog_1207_li
If the drive with the database files was disconnected or unmounted while writing, sometimes a stack overflow exception was thrown instead of a IO exception.
@changelog_1199_li
@changelog_1208_li
The H2 Console could not be shut down from within the tool if the browser supports keepAlive (most browsers do).
@changelog_1200_li
@changelog_1209_li
If the password was passed as a char array, it was kept in an internal buffer longer than required. Theoretically the password could have been stolen if the main memory was swapped to disk before the garbage collection was run.
@changelog_1201_h2
@changelog_1210_h2
Version 1.0.72 (2008-05-10)
@changelog_1202_li
@changelog_1211_li
Some databases could not be opened when appending ;RECOVER=1 to the database URL.
@changelog_1203_li
@changelog_1212_li
The Japanese translation of the error messages and the H2 Console has been completed by Masahiro Ikemoto (Arizona Design Inc.)
@changelog_1204_li
@changelog_1213_li
Updates made to updatable rows are now visible within the same result set. DatabaseMetaData.ownUpdatesAreVisible now returns true.
@changelog_1205_li
@changelog_1214_li
ParameterMetaData now returns the correct data for INSERT and UPDATE statements.
@changelog_1206_li
@changelog_1215_li
H2 Shell: DESCRIBE now supports an schema name.
@changelog_1207_li
@changelog_1216_li
A subset of the PostgreSQL 'dollar quoting' feature is now supported.
@changelog_1208_li
@changelog_1217_li
SLF4J is now supported by using adding TRACE_LEVEL_FILE=4 to the database URL.
@changelog_1209_li
@changelog_1218_li
The recovery tool did not work if the table name contained spaces or if there was a comment on the table.
@changelog_1210_li
@changelog_1219_li
Triggers are no longer executed when changing the table structure (ALTER TABLE).
@changelog_1211_li
@changelog_1220_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.
@changelog_1212_li
@changelog_1221_li
Statements can now be canceled remotely (when using remote connections).
@changelog_1213_li
@changelog_1222_li
The Shell tool now uses java.io.Console to read the password when using JDK 1.6
@changelog_1214_li
@changelog_1223_li
When using read-only databases and setting LOG=2, an exception was written to the trace file when closing the database. Fixed.
@changelog_1215_h2
@changelog_1224_h2
Version 1.0.71 (2008-04-25)
@changelog_1216_li
@changelog_1225_li
H2 is now dual-licensed under the Eclipse Public License (EPL) and the old 'H2 License' (which is basically MPL).
@changelog_1217_li
@changelog_1226_li
Sometimes an exception 'File ID mismatch' or 'try to add a record twice' occurred after large records (8 KB or larger) are updated or deleted. See also http://code.google.com/p/h2database/issues/detail?id=22
@changelog_1218_li
@changelog_1227_li
H2 Console: The tools can now be translated (it didn't work in the last release).
@changelog_1219_li
@changelog_1228_li
New traditional Chinese translation. Thanks a lot to Derek Chao!
@changelog_1220_li
@changelog_1229_li
Indexes were not used when enabling the optimization for IN(SELECT...) (system property h2.optimizeInJoin).
@changelog_1221_h2
@changelog_1230_h2
Version 1.0.70 (2008-04-20)
@changelog_1222_li
@changelog_1231_li
The plan is to dual-license H2. The additional license is EPL (Eclipse Public License). The current license (MPL, Mozilla Public License) will stay. Current users are not affected because they can keep MPL. EPL is very similar to MPL, the only bigger difference is related to patents (EPL is a bit more business friendly in this regard). See also http://opensource.org/licenses/eclipse-1.0.php, http://www.eclipse.org/legal/eplfaq.php (FAQ), http://blogs.zdnet.com/Burnette/?p=131
@changelog_1223_li
@changelog_1232_li
Multi version concurrency (MVCC): when a row was updated, and the updated column was not indexed, this update was visible sometimes for other sessions even if it was not committed.
@changelog_1224_li
@changelog_1233_li
Calling SHUTDOWN on one connection and starting a query on another connection concurrently could result in a Java level deadlock.
@changelog_1225_li
@changelog_1234_li
New system property h2.enableAnonymousSSL (default: true) to enable anonymous SSL connections.
@changelog_1226_li
@changelog_1235_li
The precision if SUBSTR is now calculated if possible.
@changelog_1227_li
@changelog_1236_li
The autocomplete in the H2 Console has been improved a bit.
@changelog_1228_li
@changelog_1237_li
The tools in the H2 Console are now translatable.
@changelog_1229_li
@changelog_1238_li
The servlet and lucene jar files are now automatically downloaded when building.
@changelog_1230_li
@changelog_1239_li
The code switch tool has been replaced by a simpler tool called SwitchSource that just uses find and replace.
@changelog_1231_li
@changelog_1240_li
Started to write a Ant replacement ('JAnt') that uses pure Java build definitions. Advantages: ability to debug the build, extensible, flexible, no XML, a bit faster. Future plan: support creating custom h2 distributions (for embedded use). Maybe create a new project 'Jant' or 'Javen' if other people are interested.
@changelog_1232_li
@changelog_1241_li
The jar file is now about 10% smaller because the variable debugging info is no longer included. The source file and line number debugging info is still included. If required, the jar file size of the full version can be further reduced to about 720 KB using 'build jarSmall' or even more by removing unneeded components.
@changelog_1233_li
@changelog_1242_li
Added shell scripts run.sh and build.sh. chmod +x is required, but otherwise it should work. Feedback or improvements are welcome!
@changelog_1234_li
@changelog_1243_li
Databases in zip files: large queries are now supported. Temp files are created in the temp directory if required. The documentation how to create the zip file has been corrected.
The Japanese translation of the error messages and the H2 Console has been improved. Thanks a lot to Masahiro IKEMOTO.
@changelog_1237_li
@changelog_1246_li
Optimization for MIN() and MAX() when using MVCC.
@changelog_1238_li
@changelog_1247_li
To protect against remote brute force password attacks, the delay after each unsuccessful login now gets double as long. New system properties h2.delayWrongPasswordMin and h2.delayWrongPasswordMax.
@changelog_1239_li
@changelog_1248_li
After setting the query timeout and then resetting it, the next query would still timeout. Fixed.
@changelog_1240_li
@changelog_1249_li
Adding a IDENTITY column to a table with data threw a lock timeout.
@changelog_1241_li
@changelog_1250_li
OutOfMemoryError could occur when using EXISTS or IN(SELECT ..).
@changelog_1242_li
@changelog_1251_li
The built-in connection pool is not called JdbcConnectionPool. The API and documentation has been changed.
@changelog_1243_li
@changelog_1252_li
The ConvertTraceFile tool now generates SQL statement statistics at the end of the SQL script file (similar to the profiling data generated when using java -Xrunhprof).
@changelog_1244_li
@changelog_1253_li
Nested joins are now supported (A JOIN B JOIN C ON .. ON ..)
@changelog_1245_h2
@changelog_1254_h2
Version 1.0.69 (2008-03-29)
@changelog_1246_li
@changelog_1255_li
Most command line tools can now be called from within the H2 Console.
@changelog_1247_li
@changelog_1256_li
A new Shell tools is now included (org.h2.tools.Shell) to query a database from the command line.
@changelog_1248_li
@changelog_1257_li
The command line options in the tools have changed: instead of '-log true' now '-trace' is used. Also, '-ifExists', '-tcpSSL' and '-tcpAllowOthers' and so on have changed: now the 'true' is no longer needed. The old behavior is still supported.
@changelog_1249_li
@changelog_1258_li
New system property h2.sortNullsHigh to invert the default sorting behavior for NULL. The default didn't change.
@changelog_1250_li
@changelog_1259_li
Performance was very slow when using LOG=2 and deleting or updating all rows of a table in a loop. Fixed.
@changelog_1251_li
@changelog_1260_li
ALTER TABLE or CREATE TABLE now support parameters for the password field.
@changelog_1252_li
@changelog_1261_li
The linear hash has been removed. It was always slower than the b-tree index, and there were some bugs that would be hard to fix.
@changelog_1253_li
@changelog_1262_li
TRACE_LEVEL_ settings are no longer persistent. This was a problem when database initialization code caused a lot of trace output.
@changelog_1254_li
@changelog_1263_li
Fulltext search (native implementation): The words table is no longer an in-memory table because this caused memory problems in some cases.
@changelog_1255_li
@changelog_1264_li
It was possible to create a role with the name as an existing user (but not vice versa). This is not allowed any more.
@changelog_1256_li
@changelog_1265_li
The recovery tool didn't work correctly for tables without rows.
@changelog_1257_li
@changelog_1266_li
For years below 1, the YEAR method didn't return the correct value, and the conversion from date and timestamp to varchar was incorrect.
@changelog_1258_li
@changelog_1267_li
CSVWRITE caused a NullPointerException when not specifying a nullString.
@changelog_1259_li
@changelog_1268_li
When a log file switch occurred just after a truncate table or drop table statement, the database could not be started normally (RECOVER=1 was required). Fixed.
@changelog_1260_li
@changelog_1269_li
When a log file switch occurred in the middle of a sequence flush (sequences are only flushed every 32 values by default), the sequence value was lost. Fixed.
@changelog_1261_li
@changelog_1270_li
Altering a sequence didn't unlock the system table when autocommit switched off.
@changelog_1262_h2
@changelog_1271_h2
Version 1.0.68 (2008-03-18)
@changelog_1263_li
@changelog_1272_li
Very large SELECT DISTINCT and UNION EXCEPT queries are now supported, however this feature is disabled by default. To enable it, set the system property h2.maxMemoryRowsDistinct to a lower value, for example 10000.
@changelog_1264_li
@changelog_1273_li
A error is now thrown when trying to call a method inside a trigger that implicitly commits the current transaction, if an object is locked.
@changelog_1265_li
@changelog_1274_li
Unused LOB files were deleted much too late. Now they are deleted if no longer referenced in memory.
@changelog_1266_li
@changelog_1275_li
ALTER SEQUENCE and ALTER TABLE ALTER COLUMN RESTART can now be used inside a transaction.
@changelog_1267_li
@changelog_1276_li
New system property h2.aliasColumnName. When enabled, aliased columns (as in SELECT ID AS I FROM TEST) return the real table and column name in ResultSetMetaData.getTableName() and getColumnName(). This is disabled by default for compatibility with other databases (HSQLDB, Apache Derby, PostgreSQL, some version of MySQL). In version 1.1 this setting will be enabled.
@changelog_1268_li
@changelog_1277_li
When using encrypted databases, and using the wrong file password, the log file was renamed if the database was not already open. Fixed.
@changelog_1269_li
@changelog_1278_li
Improved performance when using lob files in directories (however this is still disabled by default)
@changelog_1270_li
@changelog_1279_li
H2 Console: autocomplete didn't work with very large scripts. Fixed.
@changelog_1271_li
@changelog_1280_li
Fulltext search: new method SEARCH_DATA that returns the column names and primary keys as arrays.
@changelog_1272_li
@changelog_1281_li
New experimental optimization for GROUP BY queries if an index can be used that matches the group by columns. To enable this optimization, set the system property h2.optimizeGroupSorted to true.
@changelog_1273_li
@changelog_1282_li
When using multi-version concurrency (MVCC=TRUE), duplicate rows could appear in the result set when running queries with uncommitted changes in the same session.
@changelog_1274_li
@changelog_1283_li
H2 Console: remote connections were very slow because getHostName/getRemoteHost was used. Fixed (now using getHostAddress/getRemoteAddr.
@changelog_1275_li
@changelog_1284_li
H2 Console: on Linux, Firefox, Konqueror, or Opera (in this order) are now started if available. This has been tested on Ubuntu.
@changelog_1276_li
@changelog_1285_li
H2 Console: the start window works better with IKVM
@changelog_1277_li
@changelog_1286_li
H2 Console: improved compatibility with Safari (Safari requires keep-alive)
@changelog_1278_li
@changelog_1287_li
Random: the process didn't stop if generating the random seed using the standard way (SecureRandom.generateSeed) was very slow. Now using a daemon thread to avoid this problem.
@changelog_1279_li
@changelog_1288_li
SELECT UNION with a different number of ORDER BY columns did throw an ArrayIndexOutOfBoundsException.
@changelog_1280_li
@changelog_1289_li
When using a view, the column precision was changed to the default scale for some data types.
@changelog_1281_li
@changelog_1290_li
CSVWRITE now supports a 'null string' that is used for parsing and writing NULL.
@changelog_1282_li
@changelog_1291_li
Some long running queries could not be canceled.
@changelog_1283_li
@changelog_1292_li
Queries with many outer join tables were very slow. Fixed.
@changelog_1284_li
@changelog_1293_li
The performance of text comparison has been improved when using locale sensitive string comparison (SET COLLATOR). Now CollationKey is used with a LRU cache. The default cache size is 10000, and can be changed using the system property h2.collatorCacheSize. Use 0 to disable the cache.
@changelog_1285_li
@changelog_1294_li
UPDATE SET column=DEFAULT is now supported.
@changelog_1286_h2
@changelog_1295_h2
Version 1.0.67 (2008-02-22)
@changelog_1287_li
@changelog_1296_li
New function FILE_READ to read a file or from an URL. Both binary and text data is supported.
@changelog_1288_li
@changelog_1297_li
CREATE TABLE AS SELECT now supports specifying the column list and data types.
@changelog_1289_li
@changelog_1298_li
Connecting to a TCP server and at shutting it down at the same time could cause a Java level deadlock.
@changelog_1290_li
@changelog_1299_li
A user now has all rights on his own local temporary tables.
@changelog_1291_li
@changelog_1300_li
The CSV tool now supports a custom lineSeparator.
@changelog_1292_li
@changelog_1301_li
When using multiple connections, empty space was reused too early sometimes. This could corrupt the database when recovering.
@changelog_1293_li
@changelog_1302_li
The H2 Console has been translated to Dutch. Thanks a lot to Remco Schoen!
@changelog_1294_li
@changelog_1303_li
Databases can now be opened even if trigger classes are not in the classpath. The exception is thrown when trying to fire the trigger.
@changelog_1295_li
@changelog_1304_li
Opening databases with ACCESS_MODE_DATA=r is now supported. In this case the database is read-only, but the files don't not need to be read-only.
@changelog_1296_li
@changelog_1305_li
Security: The database now waits 200 ms before throwing an exception if the user name or password don't match, to slow down dictionary attacks.
@changelog_1297_li
@changelog_1306_li
The value cache is now a soft reference cache. This should help save memory.
@changelog_1298_li
@changelog_1307_li
CREATE INDEX on a table with many rows could run out of memory. Fixed.
@changelog_1299_li
@changelog_1308_li
Large result sets are now a bit faster.
@changelog_1300_li
@changelog_1309_li
ALTER TABLE ALTER COLUMN RESTART and ALTER SEQUENCE now support parameters (any expressions).
@changelog_1301_li
@changelog_1310_li
When setting the base directory on the command line, the user directory prefix ('~') was ignored.
@changelog_1302_li
@changelog_1311_li
The DbStarter servlet didn't start the TCP listener even if configured.
@changelog_1303_li
@changelog_1312_li
Statement.setQueryTimeout() is now supported.
@changelog_1304_li
@changelog_1313_li
New session setting QUERY_TIMEOUT, and new system property h2.maxQueryTimeout.
@changelog_1305_li
@changelog_1314_li
Changing the transaction log level (SET LOG) is now written to the trace file by default.
@changelog_1306_li
@changelog_1315_li
In a SQL script, primary key constraints are now ordered before foreign key constraints.
@changelog_1307_li
@changelog_1316_li
It was not possible to create a referential constraint to a table in a different schema in some situations.
@changelog_1308_li
@changelog_1317_li
The H2 Console was slow when the database contains many tables. Now the column names are not shown in this case.
@changelog_1309_h2
@changelog_1318_h2
Version 1.0.66 (2008-02-02)
@changelog_1310_li
@changelog_1319_li
There is a new online error analyzer tool.
@changelog_1311_li
@changelog_1320_li
H2 Console: stack traces are now links to the source code in the source repository (H2 database only).
@changelog_1312_li
@changelog_1321_li
CHAR data type equals comparison was case insensitive instead of case sensitive.
@changelog_1313_li
@changelog_1322_li
The exception 'Value too long for column' now includes the data.
@changelog_1314_li
@changelog_1323_li
The table name was missing in the documentation of CREATE INDEX.
@changelog_1315_li
@changelog_1324_li
Better support for IKVM (www.ikvm.net): the H2 Console now opens a browser window.
@changelog_1316_li
@changelog_1325_li
The cache size was not correctly calculated for tables with large objects (specially if compression is used). This could lead to out-of-memory exceptions.
@changelog_1317_li
@changelog_1326_li
The exception "Hexadecimal string contains non-hex character" was not always thrown when it should have been. Fixed.
@changelog_1318_li
@changelog_1327_li
The H2 Console now provides a link to the documentation when an error occurs (H2 databases only so far).
@changelog_1319_li
@changelog_1328_li
The acting as PostgreSQL server, when a base directory was set, and the H2 Console was started as well, the base directory was applied twice.
@changelog_1320_li
@changelog_1329_li
Calling EXTRACT(HOUR FROM ...) or EXTRACT(HH FROM ...) returned the wrong values (0 to 11 instead of 0 to 23). All other tested databases return values from 0 to 23. Please check if your application relies on the old behavior before upgrading.
@changelog_1321_li
@changelog_1330_li
For compatibility with other databases the column default (COLUMN_DEF) for columns without default is now null (it was an empty string).
@changelog_1322_li
@changelog_1331_li
Statements that contain very large subqueries (where the subquery result does not fit in memory) are now faster.
@changelog_1323_li
@changelog_1332_li
Variables: large objects (CLOB and BLOB) that don't fit in memory did not work correctly when used as variables.
@changelog_1324_li
@changelog_1333_li
Fulltext search is now supported in named in-memory databases.
@changelog_1325_li
@changelog_1334_li
H2 Console: multiple consecutive spaces in the setting name did not work. Fixed.
@changelog_1326_h2
@changelog_1335_h2
Version 1.0.65 (2008-01-18)
@changelog_1327_li
@changelog_1336_li
The build (ant) now automatically switches the source code to the correct version (JDK 1.4/1.5 or 1.6).
@changelog_1328_li
@changelog_1337_li
A recovery bug has been fixed. With older versions, it was necessary to add ;RECOVER=1 to the database URL in cases where it should not have been required.
@changelog_1329_li
@changelog_1338_li
The performance for DROP and DROP ALL OBJECTS has been improved.
@changelog_1330_li
@changelog_1339_li
The ChangePassword API has been improved.
@changelog_1331_li
@changelog_1340_li
User defined variables are now supported. Examples: SET @VAR=10;CALL @VAR. This can be used for running totals as in: select x, set(@t, ifnull(@t, 0) + x) from system_range(1, 10)
@changelog_1332_li
@changelog_1341_li
The Ukrainian translation has been improved.
@changelog_1333_li
@changelog_1342_li
CALL statements can now be used in batch updates and called using Statement.executeUpdate.
@changelog_1334_li
@changelog_1343_li
New read-only setting CREATE_BUILD (the build number of the database engine that created the database).
@changelog_1335_li
@changelog_1344_li
The optimizer did not use multi column indexes for range queries in some cases. Fixed.
@changelog_1336_li
@changelog_1345_li
The H2 Console now calls DataSource.getConnection() instead of DataSource.getConnection(user, password) when user name and password are not specified.
@changelog_1337_li
@changelog_1346_li
The bind IP address can now be set when using multi-homed host (if multiple network adapters are available) using the system property h2.bindAddress.
@changelog_1338_li
@changelog_1347_li
Batch update: Calling BatchUpdateException.printStackTrace() could result in out of memory. Fixed.
@changelog_1339_li
@changelog_1348_li
Indexes of unique or foreign constraints where not dropped when the constraint was dropped after altering the table (for example dropping a column). Fixed.
@changelog_1340_li
@changelog_1349_li
The performance for large result sets in the server mode has been improved.
@changelog_1341_li
@changelog_1350_li
The setting h2.serverSmallResultSetSize has been renamed to h2.serverResultSetFetchSize.
@changelog_1342_li
@changelog_1351_li
The SCRIPT command now uses multi-row insert statements to save space except if the option SIMPLE is used.
@changelog_1343_li
@changelog_1352_li
The SCRIPT command did not split up CLOB data correctly. Fixed.
@changelog_1344_li
@changelog_1353_li
Optimization for single column distinct queries with an index: select distinct name from test. Can be disabled by setting the system property h2.optimizeDistinct to false.
@changelog_1345_li
@changelog_1354_li
DROP ALL OBJECTS did not drop user defined aggregate functions and domains.
@changelog_1346_li
@changelog_1355_li
PostgreSQL compatibility: COUNT(T.*) is now supported.
@changelog_1347_li
@changelog_1356_li
LIKE comparisons are now faster.
@changelog_1348_li
@changelog_1357_li
Encrypted databases are now faster.
@download_1000_h1
...
...
@@ -5615,45 +5642,51 @@ SmartFoxServer
Platform for developing multiuser applications and games with Macromedia Flash.
@links_1175_a
StorYBook
SQLOrm
@links_1176_p
A summary-based tool for novelist and script writers. It helps to keep the overview over the various traces a story has.
Java Object Relation Mapping.
@links_1177_a
StreamCruncher
StorYBook
@links_1178_p
Event (stream) processing kernel.
A summary-based tool for novelist and script writers. It helps to keep the overview over the various traces a story has.
@links_1179_a
Tune Backup
StreamCruncher
@links_1180_p
Easy-to-use backup solution for your iTunes library.
Event (stream) processing kernel.
@links_1181_a
weblica
Tune Backup
@links_1182_p
Desktop CMS.
Easy-to-use backup solution for your iTunes library.
@links_1183_a
Web of Web
weblica
@links_1184_p
Collaborative and realtime interactive media platform for the web.
Desktop CMS.
@links_1185_a
Werkzeugkasten
Web of Web
@links_1186_p
Minimum Java Toolset.
Collaborative and realtime interactive media platform for the web.
@links_1187_a
Volunteer database
Werkzeugkasten
@links_1188_p
Minimum Java Toolset.
@links_1189_a
Volunteer database
@links_1190_p
A database front end to register volunteers, partnership and donation for a Non Profit organization.
@mainWeb_1000_h1
...
...
@@ -6907,91 +6940,103 @@ ms
@performance_1381_td
87112
@performance_1382_h2
@performance_1382_p
There are a few problems with the PolePosition test:
@performance_1383_li
HSQLDB uses in-memory tables by default while H2 uses persistent tables. The HSQLDB version included in PolePosition does not support changing this, so you need to replace poleposition-0.20/lib/hsqldb.jar with a newer version (for example hsqldb-1.8.0.7.jar), and then use the setting hsqldb.connecturl=jdbc:hsqldb:file:data/hsqldb/dbbench2;hsqldb.default_table_type=cached;sql.enforce_size=true in Jdbc.properties.
@performance_1384_li
HSQLDB keeps the database open between tests, while H2 closes the database (losing all the cache). To change that, use the database URL jdbc:h2:file:data/h2/dbbench;DB_CLOSE_DELAY=-1
@performance_1385_li
The amount of cache memory is quite important, specially for the PolePosition test. Unfortunately, the PolePosition test does not take this into account.
@performance_1386_h2
Application Profiling
@performance_1383_h3
@performance_1387_h3
Analyze First
@performance_1384_p
@performance_1388_p
Before trying to optimize the performance, it is important to know where the time is actually spent. The same is true for memory problems. Premature or 'blind' optimization should be avoided, as it is not an efficient way to solve the problem. There are various ways to analyze the application. In some situations it is possible to compare two implementations and use System.currentTimeMillis() to find out which one is faster. But this does not work for complex applications with many modules, and for memory problems.
@performance_1385_p
@performance_1389_p
A very good tool to measure both the memory and the CPU is the <a href="http://www.yourkit.com">YourKit Java Profiler</a> . This tool is also used to optimize the performance and memory footprint of this database engine.
@performance_1386_p
@performance_1390_p
A simple way to profile an application is to use the built-in profiling tool of java. Example:
@performance_1387_p
@performance_1391_p
Unfortunately, it is only possible to profile the application from start to end.
@performance_1388_h2
@performance_1392_h2
Database Profiling
@performance_1389_p
@performance_1393_p
The ConvertTraceFile tool generates SQL statement statistics at the end of the SQL script file. The format used is similar to the profiling data generated when using java -Xrunhprof. As an example, execute the the following script using the H2 Console:
@performance_1390_p
@performance_1394_p
Now convert the .trace.db file using the ConvertTraceFile tool:
@performance_1391_p
@performance_1395_p
The generated file <code>test.sql</code> will contain the SQL statements as well as the following profiling data (results vary):
@performance_1392_h2
@performance_1396_h2
Database Performance Tuning
@performance_1393_h3
@performance_1397_h3
Virus Scanners
@performance_1394_p
@performance_1398_p
Some virus scanners scan files every time they are accessed. It is very important for performance that database files are not scanned for viruses. The database engine does never interprets the data stored in the files as programs, that means even if somebody would store a virus in a database file, this would be harmless (when the virus does not run, it cannot spread). Some virus scanners allow excluding file endings. Make sure files ending with .db are not scanned.
@performance_1395_h3
@performance_1399_h3
Using the Trace Options
@performance_1396_p
@performance_1400_p
If the main performance hot spots are in the database engine, in many cases the performance can be optimized by creating additional indexes, or changing the schema. Sometimes the application does not directly generate the SQL statements, for example if an O/R mapping tool is used. To view the SQL statements and JDBC API calls, you can use the trace options. For more information, see <a href="features.html#trace_options">Using the Trace Options</a> .
@performance_1397_h3
@performance_1401_h3
Index Usage
@performance_1398_p
@performance_1402_p
This database uses indexes to improve the performance of SELECT, UPDATE and DELETE statements. If a column is used in the WHERE clause of a query, and if an index exists on this column, then the index can be used. Multi-column indexes are used if all or the first columns of the index are used. Both equality lookup and range scans are supported. Indexes are not used to order result sets: The results are sorted in memory if required. Indexes are created automatically for primary key and unique constraints. Indexes are also created for foreign key constraints, if required. For other columns, indexes need to be created manually using the CREATE INDEX statement.
@performance_1399_h3
@performance_1403_h3
Optimizer
@performance_1400_p
@performance_1404_p
This database uses a cost based optimizer. For simple and queries and queries with medium complexity (less than 7 tables in the join), the expected cost (running time) of all possible plans is calculated, and the plan with the lowest cost is used. For more complex queries, the algorithm first tries all possible combinations for the first few tables, and the remaining tables added using a greedy algorithm (this works well for most joins). Afterwards a genetic algorithm is used to test at most 2000 distinct plans. Only left-deep plans are evaluated.
@performance_1401_h3
@performance_1405_h3
Expression Optimization
@performance_1402_p
@performance_1406_p
After the statement is parsed, all expressions are simplified automatically if possible. Operations are evaluated only once if all parameters are constant. Functions are also optimized, but only if the function is constant (always returns the same result for the same parameter values). If the WHERE clause is always false, then the table is not accessed at all.
@performance_1403_h3
@performance_1407_h3
COUNT(*) Optimization
@performance_1404_p
@performance_1408_p
If the query only counts all rows of a table, then the data is not accessed. However, this is only possible if no WHERE clause is used, that means it only works for queries of the form SELECT COUNT(*) FROM table.
When executing a query, at most one index per joined table can be used. If the same table is joined multiple times, for each join only one index is used. Example: for the query SELECT * FROM TEST T1, TEST T2 WHERE T1.NAME='A' AND T2.ID=T1.ID, two index can be used, in this case the index on NAME for T1 and the index on ID for T2.
@performance_1407_p
@performance_1411_p
If a table has multiple indexes, sometimes more than one index could be used. Example: if there is a table TEST(ID, NAME, FIRSTNAME) and an index on each column, then two indexes could be used for the query SELECT * FROM TEST WHERE NAME='A' AND FIRSTNAME='B', the index on NAME or the index on FIRSTNAME. It is not possible to use both indexes at the same time. Which index is used depends on the selectivity of the column. The selectivity describes the 'uniqueness' of values in a column. A selectivity of 100 means each value appears only once, and a selectivity of 1 means the same value appears in many or most rows. For the query above, the index on NAME should be used if the table contains more distinct names than first names.
@performance_1408_p
@performance_1412_p
The SQL statement ANALYZE can be used to automatically estimate the selectivity of the columns in the tables. This command should be run from time to time to improve the query plans generated by the optimizer.
@performance_1409_h3
@performance_1413_h3
Optimization Examples
@performance_1410_p
@performance_1414_p
See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
@quickstart_1000_h1
...
...
@@ -7184,7 +7229,7 @@ Clustering: recovery needs to becomes fully automatic. Global write lock feature
Option for Java functions: [DETERMINISTIC] FOR ...
@roadmap_1031_li
Improved fulltext search (supports LOBs).
Fulltext search: support streaming CLOB data.
@roadmap_1032_li
Support mixed clustering mode (one embedded, the other server mode)
...
...
@@ -7565,7 +7610,7 @@ Make sure H2 is supported by Execute Query: http://executequery.org/
Read InputStream when executing, as late as possible (maybe only embedded mode). Problem with re-execute.
@roadmap_1158_li
Fulltext search: min word length; store word positions
Native fulltext search: min word length; store word positions
@roadmap_1159_li
FTP Server: Implement a client to send / receive files to server (dir, get, put)
...
...
@@ -7808,360 +7853,366 @@ Store dates as 'local'. Existing files use GMT. Use escape syntax for compatibil
Support data type INTERVAL
@roadmap_1239_li
NATURAL JOIN: MySQL and PostgreSQL don't repeat columns when using SELECT * ...
Optimize SELECT MIN(ID), MAX(ID), COUNT(*) FROM TEST WHERE ID BETWEEN 100 AND 200
@roadmap_1240_li
Optimize SELECT MIN(ID), MAX(ID), COUNT(*) FROM TEST WHERE ID BETWEEN 100 AND 200
Support Oracle functions: TRUNC, NVL2, TO_CHAR, TO_DATE, TO_NUMBER
@roadmap_1241_li
Support Oracle functions: TRUNC, NVL2, TO_CHAR, TO_DATE, TO_NUMBER
Triggers for metadata tables; use for PostgreSQL catalog
@roadmap_1268_li
Javadoc: document design patterns used
Does the FTP server has problems with multithreading?
@roadmap_1269_li
Triggers for metadata tables; use for PostgreSQL catalog
Write an article about SQLInjection (h2\src\docsrc\html\images\SQLInjection.txt)
@roadmap_1270_li
Does the FTP server has problems with multithreading?
Convert SQL-injection-2.txt to html document, include SQLInjection.java sample
@roadmap_1271_li
Write an article about SQLInjection (h2\src\docsrc\html\images\SQLInjection.txt)
Send SQL Injection solution proposal to MySQL, Derby, HSQLDB,...
@roadmap_1272_li
Convert SQL-injection-2.txt to html document, include SQLInjection.java sample
Improve LOB in directories performance
@roadmap_1273_li
Send SQL Injection solution proposal to MySQL, Derby, HSQLDB,...
Optimize OR conditions: convert them to IN(...) if possible.
@roadmap_1274_li
Improve LOB in directories performance
Web site design: http://www.igniterealtime.org/projects/openfire/index.jsp
@roadmap_1275_li
Optimize OR conditions: convert them to IN(...) if possible.
HSQLDB compatibility: Openfire server uses: CREATE SCHEMA PUBLIC AUTHORIZATION DBA; CREATE USER SA PASSWORD ""; GRANT DBA TO SA; SET SCHEMA PUBLIC
@roadmap_1276_li
Web site design: http://www.igniterealtime.org/projects/openfire/index.jsp
Web site: Rename Performance to Comparison [/Compatibility], move Comparison to Other Database Engines to Comparison, move Products that Work with H2 to Comparison, move Performance Tuning to Advanced Topics
@roadmap_1277_li
HSQLDB compatibility: Openfire server uses: CREATE SCHEMA PUBLIC AUTHORIZATION DBA; CREATE USER SA PASSWORD ""; GRANT DBA TO SA; SET SCHEMA PUBLIC
Support JMX: Create an MBean for each database and server (support JConsole). See http://thedevcloud.blogspot.com/2008/10/displaying-hsql-database-manager-in.html
@roadmap_1278_li
Web site: Rename Performance to Comparison [/Compatibility], move Comparison to Other Database Engines to Comparison, move Products that Work with H2 to Comparison, move Performance Tuning to Advanced Topics
Translation: use ?? in help.csv
@roadmap_1279_li
Support JMX: Create an MBean for each database and server (support JConsole). See http://thedevcloud.blogspot.com/2008/10/displaying-hsql-database-manager-in.html
Translated .pdf
@roadmap_1280_li
Translation: use ?? in help.csv
Cluster: hot deploy (adding a node at runtime)
@roadmap_1281_li
Translated .pdf
MySQL compatibility: update test1 t1, test2 t2 set t1.id = t2.id where t1.id = t2.id;
@roadmap_1282_li
Cluster: hot deploy (adding a node at runtime)
Try again with Lobo browser (pure Java)
@roadmap_1283_li
MySQL compatibility: update test1 t1, test2 t2 set t1.id = t2.id where t1.id = t2.id;
Recovery tool: bad blocks should be converted to INSERT INTO SYSTEM_ERRORS(...), and things should go into the .trace.db file
@roadmap_1284_li
Try again with Lobo browser (pure Java)
RECOVER=2 to backup the database, run recovery, open the database
@roadmap_1285_li
Recovery tool: bad blocks should be converted to INSERT INTO SYSTEM_ERRORS(...), and things should go into the .trace.db file
Recovery should work with encrypted databases
@roadmap_1286_li
RECOVER=2 to backup the database, run recovery, open the database
Corruption: new error code, add help
@roadmap_1287_li
Recovery should work with encrypted databases
Space reuse: after init, scan all storages and free those that don't belong to a live database object
@roadmap_1288_li
Corruption: new error code, add help
SysProperties: change everything to H2_...
@roadmap_1289_li
Space reuse: after init, scan all storages and free those that don't belong to a live database object
Use FilterIn / FilterOut putStream?
@roadmap_1290_li
SysProperties: change everything to H2_...
Access rights: add missing features (users should be 'owner' of objects; missing rights for sequences; dropping objects)
@roadmap_1291_li
Use FilterIn / FilterOut putStream?
Support NOCACHE table option (Oracle)
@roadmap_1292_li
Access rights: add missing features (users should be 'owner' of objects; missing rights for sequences; dropping objects)
Index usage for UPDATE ... WHERE .. IN (SELECT...)
@roadmap_1293_li
Support NOCACHE table option (Oracle)
Add regular javadocs (using the default doclet, but another css) to the homepage.
@roadmap_1294_li
Index usage for UPDATE ... WHERE .. IN (SELECT...)
The database should be kept open for a longer time when using the server mode.
@roadmap_1295_li
Add regular javadocs (using the default doclet, but another css) to the homepage.
Javadocs: for each tool, add a copy & paste sample in the class level.
@roadmap_1296_li
The database should be kept open for a longer time when using the server mode.
Javadocs: add @author tags.
@roadmap_1297_li
Javadocs: for each tool, add a copy & paste sample in the class level.
Fluent API for tools: Server.createTcpServer().setPort(9081).setPassword(password).start();
@roadmap_1298_li
Javadocs: add @author tags.
MySQL compatibility: real SQL statements for SHOW TABLES, DESCRIBE TEST (then remove from Shell)
@roadmap_1299_li
Fluent API for tools: Server.createTcpServer().setPort(9081).setPassword(password).start();
Use a default delay of 1 second before closing a database.
@roadmap_1300_li
MySQL compatibility: real SQL statements for SHOW TABLES, DESCRIBE TEST (then remove from Shell)
Maven: upload source code and javadocs as well.
@roadmap_1301_li
Use a default delay of 1 second before closing a database.
Write (log) to system table before adding to internal data structures.
@roadmap_1302_li
Maven: upload source code and javadocs as well.
Support very large deletes and updates.
@roadmap_1303_li
Write (log) to system table before adding to internal data structures.
Doclet (javadocs): constructors are not listed.
@roadmap_1304_li
Support very large deletes and updates.
Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup).
@roadmap_1305_li
Doclet (javadocs): constructors are not listed.
Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object);
@roadmap_1306_li
Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup).
MVCC should not be memory bound (uncommitted data is kept in memory in the delta index; maybe using a regular btree index solves the problem).
@roadmap_1307_li
Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object);
Support CREATE TEMPORARY LINKED TABLE.
@roadmap_1308_li
MVCC should not be memory bound (uncommitted data is kept in memory in the delta index; maybe using a regular btree index solves the problem).
MySQL compatibility: SELECT @variable := x FROM SYSTEM_RANGE(1, 50);
@roadmap_1309_li
Support CREATE TEMPORARY LINKED TABLE.
Oracle compatibility: support NLS_DATE_FORMAT.
@roadmap_1310_li
MySQL compatibility: SELECT @variable := x FROM SYSTEM_RANGE(1, 50);
Support flashback queries as in Oracle.
@roadmap_1311_li
Oracle compatibility: support NLS_DATE_FORMAT.
Import / Export of fixed with text files.
@roadmap_1312_li
Support flashback queries as in Oracle.
Support for OUT parameters in user-defined procedures.
@roadmap_1313_li
Import / Export of fixed with text files.
Support getGeneratedKeys to return multiple rows when used with batch updates. This is supported by MySQL, but not Derby. Both PostgreSQL and HSQLDB don't support getGeneratedKeys. Also support it when using INSERT ... SELECT.
@roadmap_1314_li
Support for OUT parameters in user-defined procedures.
HSQLDB compatibility: automatic data type for SUM if value is the value is too big (by default use the same type as the data).
@roadmap_1315_li
Support getGeneratedKeys to return multiple rows when used with batch updates. This is supported by MySQL, but not Derby. Both PostgreSQL and HSQLDB don't support getGeneratedKeys. Also support it when using INSERT ... SELECT.
Improve the optimizer to select the right index for special cases: where id between 2 and 4 and booleanColumn
@roadmap_1316_li
HSQLDB compatibility: automatic data type for SUM if value is the value is too big (by default use the same type as the data).
Enable warning for 'Local variable declaration hides another field or variable'.
@roadmap_1317_li
Improve the optimizer to select the right index for special cases: where id between 2 and 4 and booleanColumn
Linked tables: make hidden columns available (Oracle: rowid and ora_rowscn columns).
@roadmap_1318_li
Enable warning for 'Local variable declaration hides another field or variable'.
Support merge join.
@roadmap_1319_li
Linked tables: make hidden columns available (Oracle: rowid and ora_rowscn columns).
H2 Console: in-place autocomplete.
@roadmap_1320_li
Support merge join.
Oracle: support DECODE method (convert to CASE WHEN).
@roadmap_1321_li
H2 Console: in-place autocomplete.
Support large databases: split LOB (BLOB, CLOB) to multiple directories / disks (similar to tablespaces).
@roadmap_1322_li
Oracle: support DECODE method (convert to CASE WHEN).
Support to assign a primary key index a user defined name.
@roadmap_1323_li
Support large databases: split LOB (BLOB, CLOB) to multiple directories / disks (similar to tablespaces).
Cluster: Add feature to make sure cluster nodes can not get out of sync (for example by stopping one process).
@roadmap_1324_li
Support to assign a primary key index a user defined name.
H2 Console: support configuration option for fixed width (monospace) font.
@roadmap_1325_li
Cluster: Add feature to make sure cluster nodes can not get out of sync (for example by stopping one process).
Native fulltext search: support analyzers (specially for Chinese, Japanese).
@roadmap_1326_li
H2 Console: support configuration option for fixed width (monospace) font.
Automatically compact databases from time to time (as a background process).
@roadmap_1327_li
Native fulltext search: support analyzers (specially for Chinese, Japanese).
Support SCOPE_IDENTITY().
@roadmap_1328_li
Automatically compact databases from time to time (as a background process).
Support GRANT SELECT, UPDATE ON *.
@roadmap_1329_li
Support SCOPE_IDENTITY().
Test Eclipse DTP.
@roadmap_1330_li
Support GRANT SELECT, UPDATE ON *.
H2 Console: autocomplete: keep the previous setting
@roadmap_1331_li
Test Eclipse DTP.
executeBatch: option to stop at the first failed statement.
@roadmap_1332_li
H2 Console: autocomplete: keep the previous setting
Implement OLAP features as described here: http://www.devx.com/getHelpOn/10MinuteSolution/16573/0/page/5
@roadmap_1333_li
executeBatch: option to stop at the first failed statement.
Support Oracle ROWID (unique identifier for each row).
@roadmap_1334_li
Implement OLAP features as described here: http://www.devx.com/getHelpOn/10MinuteSolution/16573/0/page/5
Server mode: Improve performance for batch updates.
@roadmap_1335_li
Support Oracle ROWID (unique identifier for each row).
Applets: Support read-only databases in a zip file (accessed as a resource).
@roadmap_1336_li
Server mode: Improve performance for batch updates.
Long running queries / errors / trace system table.
@roadmap_1337_li
Applets: Support read-only databases in a zip file (accessed as a resource).
H2 Console should support JaQu directly.
@roadmap_1338_li
Long running queries / errors / trace system table.
Option to copy the old version of each changed page once after a checkpoint.
@roadmap_1339_li
H2 Console should support JaQu directly.
H2 Console: support single file upload and directory download (optional).
@roadmap_1340_li
Option to copy the old version of each changed page once after a checkpoint.
Document FTL_SEARCH, FTL_SEARCH_DATA.
@roadmap_1341_li
H2 Console: support single file upload and directory download (optional).
Support DatabaseMetaData.insertsAreDetected: updatable result sets should detect inserts.
@roadmap_1342_li
Document FTL_SEARCH, FTL_SEARCH_DATA.
Auto-server: add option to define the IP address range or list.
@roadmap_1343_li
Support DatabaseMetaData.insertsAreDetected: updatable result sets should detect inserts.
Open a read-only database but don't share it with other connections. jdbc:h2:~/test;PRIVATE=TRUE
@roadmap_1344_li
Auto-server: add option to define the IP address range or list.
Index creation only using deterministic functions.
@roadmap_1345_li
Open a read-only database but don't share it with other connections. jdbc:h2:~/test;PRIVATE=TRUE
Use http://recaptcha.net somehow to secure the Google Group.
@roadmap_1346_li
Index creation only using deterministic functions.
Support DELETE with TOP or LIMIT. See also: http://dev.mysql.com/doc/refman/5.1/de/delete.html
@roadmap_1347_li
Use http://recaptcha.net somehow to secure the Google Group.
Change the default for NULL || 'x' to return NULL
@roadmap_1348_li
Support DELETE with TOP or LIMIT. See also: http://dev.mysql.com/doc/refman/5.1/de/delete.html
ANALYZE: Use a bloom filter for each indexed column to estimate count of distinct values.
@roadmap_1349_li
Change the default for NULL || 'x' to return NULL
ANALYZE: For unique indexes that allow null, count the number of null.
@roadmap_1350_li
ANALYZE: Use a bloom filter for each indexed column to estimate count of distinct values.
AUTO_SERVER: support changing IP addresses (disable a network while the database is open).
@roadmap_1351_li
ANALYZE: For unique indexes that allow null, count the number of null.
Avoid using java.util.Calendar internally because it's slow, complicated, and seems to be buggy.
@roadmap_1352_li
AUTO_SERVER: support changing IP addresses (disable a network while the database is open).
Support TRUNCATE .. CASCADE like PostgreSQL.
@roadmap_1353_li
Avoid using java.util.Calendar internally because it's slow, complicated, and seems to be buggy.
Support opening a database that is in the classpath, maybe using a new file system.
@roadmap_1354_li
Support TRUNCATE .. CASCADE like PostgreSQL.
Fulltext search: lazy result generation using SimpleRowSource.
@roadmap_1355_h2
Not Planned
@roadmap_1355_li
Support transformation to join for user defined functions, as for IN(SELECT...).
@roadmap_1356_li
Fulltext search: Support alternative syntax: WHERE FTL_CONTAINS(name, 'hello').
@roadmap_1357_h2
Not Planned
@roadmap_1358_li
HSQLDB (did) support this: select id i from test where i>0 (other databases don't). Supporting it may break compatibility.
@roadmap_1357_li
@roadmap_1359_li
String.intern (so that Strings can be compared with ==) will not be used because some VMs have problems when used extensively.
@search_1000_b
...
...
@@ -8876,50 +8927,68 @@ You need to initialize it in each database where you want to use it. Afterwards,
PUBLIC is the schema, TEST is the table name. The list of column names (column separated) is optional, in this case all columns are indexed. The index is updated in read time. To search the index, use the following query:
@tutorial_1200_p
This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1201_p
QUERY: "PUBLIC"."TEST" WHERE "ID"=1
@tutorial_1202_p
To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code> . The result contains the columns SCHEMA (the schema name), TABLE (the table name), COLUMNS (an array of column names), and KEYS (an array of objects). To join a table, use a join as in: <code>SELECT T.*FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID= FT.KEYS[0];</code>
@tutorial_1203_p
You can also call the index from within a Java application:
@tutorial_1201_h3
@tutorial_1204_h3
Using the Lucene Fulltext Search
@tutorial_1202_p
@tutorial_1205_p
To use the Lucene full text search, you need the Lucene library in the classpath. How his is done depends on the application; if you use the H2 Console, you can add the Lucene jar file to the environment variables H2DRIVERS or CLASSPATH. To initialize the Lucene full text search in a database, call:
@tutorial_1203_p
@tutorial_1206_p
You need to initialize it in each database where you want to use it. Afterwards, you can create a full text index for a table using:
@tutorial_1204_p
@tutorial_1207_p
PUBLIC is the schema, TEST is the table name. The list of column names (column separated) is optional, in this case all columns are indexed. The index is updated in read time. To search the index, use the following query:
@tutorial_1205_p
@tutorial_1208_p
This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1209_p
QUERY: "PUBLIC"."TEST" WHERE "ID"=1
@tutorial_1210_p
To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code> . The result contains the columns SCHEMA (the schema name), TABLE (the table name), COLUMNS (an array of column names), and KEYS (an array of objects). To join a table, use a join as in: <code>SELECT T.*FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID= FT.KEYS[0];</code>
@tutorial_1211_p
You can also call the index from within a Java application:
@tutorial_1206_h2
@tutorial_1212_h2
User-Defined Variables
@tutorial_1207_p
@tutorial_1213_p
This database supports user-defined variables. Variables start with @ and can be used wherever expressions or parameters are used. Variables not persisted and session scoped, that means only visible for the session where they are defined. A value is usually assigned using the SET command:
@tutorial_1208_p
@tutorial_1214_p
It is also possible to change a value using the SET() method. This is useful in queries:
@tutorial_1209_p
@tutorial_1215_p
Variables that are not set evaluate to NULL. The data type of a user-defined variable is the data type of the value assigned to it, that means it is not necessary (or possible) to declare variable names before using them. There are no restrictions on the assigned values; large objects (LOBs) are supported as well.
@tutorial_1210_h2
@tutorial_1216_h2
Date and Time
@tutorial_1211_p
@tutorial_1217_p
Date, time and timestamp values support ISO 8601 formatting, including time zone:
@tutorial_1212_p
@tutorial_1218_p
If the time zone is not set, the value is parsed using the current time zone setting of the system. Date and time information is stored in H2 database files in GMT (Greenwich Mean Time). If the database is opened using another system time zone, the date and time will change accordingly. If you want to move a database from one time zone to the other and don't want this to happen, you need to create a SQL script file using the SCRIPT command or Script tool, and then load the database using the RUNSCRIPT command or the RunScript tool in the new time zone.
@tutorial_1213_h2
@tutorial_1219_h2
Using Spring
@tutorial_1214_p
@tutorial_1220_p
Use the following configuration to start and stop the H2 TCP Server using the Spring Framework:
@tutorial_1215_p
@tutorial_1221_p
The "destroy-method" will help prevent exceptions on hot-redeployment or when restarting server.
#The fulltext search documentation has been improved.
@changelog_1003_li
#H2 Console: Columns are now listed for up to 500 tables instead of 100.
#ARRAY_GET returned the wrong data type (ARRAY). Now it returns VARCHAR.
@changelog_1004_li
#H2 Console: Cmd+Enter executes the current statement.
#Natural join: the joined columns are not repeated any more when using SELECT *.
@changelog_1005_li
#JaQu: the maximum length of a column can now be defined using maxLength. For an example, see Product.java (maxLength(category, 255)).
#User defined aggregate functions: the method getType expected internal data types instead of SQL types.
@changelog_1006_li
#R&\#305;dvan A&\#287;ar has completed the Turkish translation of the H2 Console. Thanks a lot!
#User defined aggregate functions did not work if there was no group by expression.
@changelog_1007_h2
#Version 1.1.104 (2008-11-28)
@changelog_1007_li
#MySQL compatibility: support for := assignment as in @sum:=@sum+x
@changelog_1008_li
#New meta data column INFORMATION_SCHEMA.TABLES.LAST_MODIFICATION to get the table modification counter.
#INSERT INTO TEST(SELECT * FROM TEST) is now supported.
@changelog_1009_li
#If a query that was used like a table contained group by and was ordered by an expression that is not in the column list, an exception was thrown.
#Each session threw an invisible exception when garbage collected.
@changelog_1010_li
#JaQu: tables are now auto-created when running a query.
#Foreign key constraints that refer to a quoted column did not work.
@changelog_1011_li
#The optimizer had problems with function tables (for example CSVREAD and FTL_SEARCH). A new system property h2.estimatedFunctionTableRows (default 1000) defines how many rows can be expected in the table.
#New meta data column INFORMATION_SCHEMA.TABLES.LAST_MODIFICATION to get the table modification counter.
@changelog_1012_li
#The function SUM could overflow when using large values. It returns now a data type that is safe.
#Shell: line comments didn't work correctly.
@changelog_1013_li
#The function AVG could overflow when using large values. Fixed.
#H2 Console: Columns are now listed for up to 500 tables instead of 100.
@changelog_1014_li
#The emergency reserve file has been removed. It didn't provide an appropriate solution for the problem. It is still possible for an application to detect and deal with the low disk space problem (deleting temporary files for example) using DatabaseEventListener.diskSpaceIsLow, but this method is now always called with stillAvailable=0.
#H2 Console: Cmd+Enter executes the current statement, Alt+Space for autocomplete.
@changelog_1015_li
#Build: JAVA_HOME is now automatically detected on Mac OS X.
#JaQu: the maximum length of a column can now be defined using maxLength. For an example, see Product.java (maxLength(category, 255)).
@changelog_1016_li
#R&\#305;dvan A&\#287;ar has completed the Turkish translation of the H2 Console. Thanks a lot!
@changelog_1017_h2
#Version 1.1.104 (2008-11-28)
@changelog_1018_li
#If a query that was used like a table contained group by and was ordered by an expression that is not in the column list, an exception was thrown.
@changelog_1019_li
#JaQu: tables are now auto-created when running a query.
@changelog_1020_li
#The optimizer had problems with function tables (for example CSVREAD and FTL_SEARCH). A new system property h2.estimatedFunctionTableRows (default 1000) defines how many rows can be expected in the table.
@changelog_1021_li
#The function SUM could overflow when using large values. It returns now a data type that is safe.
@changelog_1022_li
#The function AVG could overflow when using large values. Fixed.
@changelog_1023_li
#The emergency reserve file has been removed. It didn't provide an appropriate solution for the problem. It is still possible for an application to detect and deal with the low disk space problem (deleting temporary files for example) using DatabaseEventListener.diskSpaceIsLow, but this method is now always called with stillAvailable=0.
@changelog_1024_li
#Build: JAVA_HOME is now automatically detected on Mac OS X.
@changelog_1025_li
#Testing for local connections was very slow on some systems.
@changelog_1017_li
@changelog_1026_li
#The cache memory usage calculation is more conservative.
@changelog_1018_li
@changelog_1027_li
#Allocating space got slower and slower the larger the database.
@changelog_1019_li
@changelog_1028_li
#ALTER TABLE ALTER COLUMN could throw the wrong exception in the last version (Table not found).
@changelog_1020_li
@changelog_1029_li
#Updatable result sets: the key columns can now be updated.
@changelog_1021_li
@changelog_1030_li
#The H2DatabaseProvider for ActiveObjects is now included in the tools section.
@changelog_1022_li
@changelog_1031_li
#The H2Platform for Oracle Toplink Essential has been improved a bit.
@changelog_1023_li
@changelog_1032_li
#The Windows service to start H2 didn't work in version 1.1.
@changelog_1024_li
@changelog_1033_li
#File systems with a maximum file size (for example FAT) are now supported using the file prefix 'split:'. In this case the files are split in parts of 1 GB. Example URL: jdbc:h2:split:~/db/test. If you want to split into parts of 1 MB, use jdbc:h2:split:20:~/db/test (the part size is 1 << x, the default is 30 meaning 1 GB).
@changelog_1025_li
@changelog_1034_li
#The database now tries to detect if the classloader or virtual machine has almost shut down by checking if static final variables are set to null. This should help reduce exceptions when stopping the web application.
@changelog_1026_li
@changelog_1035_li
#Compatibility for MS SQL Server DATEDIFF(YYYY, .., ..)
@changelog_1027_li
@changelog_1036_li
#ResultSet.getObject for CLOB or BLOB will return a java.sql.Clob / java.sql.Blob object instead of a java.io.Reader / java.io.InputStream as in version 1.0. This behavior can be changed using the system property h2.returnLobObjects (true by default for version 1.1).
@changelog_1028_li
@changelog_1037_li
#The interface CloseListener has a new method 'remove' that is called when the trigger is dropped.
@changelog_1029_li
@changelog_1038_li
#Fulltext search: there was a memory leak when creating and dropping fulltext indexes in a loop.
@changelog_1030_h2
@changelog_1039_h2
#Version 1.1.103 (2008-11-07)
@changelog_1031_li
@changelog_1040_li
#Could not order by a formula when the formula was in the group by list but not in the select list.
@changelog_1032_li
@changelog_1041_li
#Date values that match the daylight saving time end were not allowed in times zones were the daylight saving time ends at midnight, for years larger than 2037. Example: timezone Brasilia, date 2042-10-12. This is a problem of Java, however a workaround is implemented in H2 that solves most problems (except the problems of java.util.Date itself).
@changelog_1033_li
@changelog_1042_li
#ALTER TABLE used a lot of memory when using multi-version concurrency.
@changelog_1034_li
@changelog_1043_li
#Referential integrity for in-memory databases didn't work in some cases in version 1.1.102.
@changelog_1035_li
@changelog_1044_li
#New column INFORMATION_SCHEMA.COLUMNS.SEQUENCE_NAME to get the name of the sequence for auto-increment columns.
@changelog_1036_li
@changelog_1045_li
#Aliases for built-in data types (such as MEDIUMBLOB which is an alias for BLOB) can now be re-mapped to another data type using CREATE DOMAIN. However main built-in data types (such as INTEGER) can not be re-mapped.
@changelog_1037_li
@changelog_1046_li
#The Japanese translation has been completed by Masahiro Ikemoto. Thanks a lot!
@changelog_1038_li
@changelog_1047_li
#Improved PostgreSQL compatibility for NEXTVAL and CURRVAL.
@changelog_1039_li
@changelog_1048_li
#Less heap memory is needed when multiple databases are open at the same time: The memory reserve (used to rollback after out of memory) is now global and no longer allocated for each database separately.
@changelog_1040_li
@changelog_1049_li
#New system property h2.browser to set the browser to use.
@changelog_1041_li
@changelog_1050_li
#To start the browser, java.awt.Desktop.browse is now used if available.
@changelog_1042_h2
@changelog_1051_h2
#Version 1.1.102 (2008-10-24)
@changelog_1043_li
@changelog_1052_li
#The French translation of the H2 Console has been improved by Olivier Parent. Thanks a lot!
@changelog_1044_li
@changelog_1053_li
#There was a memory leak when creating and dropping tables and indexes in a loop (persistent database only).
@changelog_1045_li
@changelog_1054_li
#SET LOG 2 was not effective if executed after opening the database.
@changelog_1046_li
@changelog_1055_li
#Translating the H2 Console is now simpler.
@changelog_1047_li
@changelog_1056_li
#Common exception (error code 23*) are no longer written to the .trace.db file by default.
@changelog_1048_li
@changelog_1057_li
#In-memory databases don't write LOBs to files any longer.
@changelog_1049_li
@changelog_1058_li
#Self referencing constraints didn't restrict deleting rows that reference itself if there is another row that references it.
@changelog_1050_li
@changelog_1059_li
#ResultSetMetaData.getColumnName now returns the alias name except for columns.
@changelog_1051_li
@changelog_1060_li
#Temporary files are now deleted when the database is closed, even if they were not garbage collected so far.
@changelog_1052_h2
@changelog_1061_h2
#Version 1.1.101 (2008-10-17)
@changelog_1053_li
@changelog_1062_li
#Errors with code 42000 - 42999 are no longer written to the trace file by default.
@changelog_1054_li
@changelog_1063_li
#Queries with more than 10 tables are now faster.
@changelog_1055_li
@changelog_1064_li
#Opening a connection with AUTO_SERVER=TRUE is now fast when the database is already open in another process (less than 0.01 seconds instead of 2 seconds).
@changelog_1056_li
@changelog_1065_li
#IF [NOT] EXISTS is supported for named constraints in ALTER TABLE ... ADD/DROP CONSTRAINT.
@changelog_1057_li
@changelog_1066_li
#The error messages have been translated to Spanish by Dario V. Fassi. Thanks a lot!
@changelog_1058_li
@changelog_1067_li
#Linked tables: the automatic connection sharing didn't work. Actually the system property h2.shareLinkedConnections was working in the opposite direction: it was disabled when set to true. Now it works as expected.
@changelog_1059_li
@changelog_1068_li
#Opening large database is now faster.
@changelog_1060_li
@changelog_1069_li
#New system property h2.socketConnectTimeout, the timeout in milliseconds to connect to a server. The default is 2000 (2 seconds).
@changelog_1061_li
@changelog_1070_li
#The wrong parameters were bound to subqueries with parameters, specially when using IN(SELECT ...) and IN(...).
@changelog_1062_li
@changelog_1071_li
#Unset parameters were not detected when the query was re-compiled.
@changelog_1063_li
@changelog_1072_li
#New functions ISO_YEAR, ISO_WEEK, ISO_DAY_OF_WEEK. Thanks a lot to Robert Rathsack for implementing those!
@changelog_1064_li
@changelog_1073_li
#The date functions DAYOFYEAR, DAYOFMONTH, DAYOFWEEK are now called DAY_OF_YEAR, DAY_OF_MONTH, DAY_OF_WEEK (the old names still work).
@changelog_1065_li
@changelog_1074_li
#An out of memory error while deleting or updating many rows could result in a strange exception.
@changelog_1066_li
@changelog_1075_li
#Linked tables: compatibility with MS SQL Server has been improved.
@changelog_1067_li
@changelog_1076_li
#Renaming tables that have foreign keys with cascade didn't work correctly.
@changelog_1068_li
@changelog_1077_li
#The auto-reconnect feature didn't work when using the auto-server mode. Fixed.
@changelog_1069_li
@changelog_1078_li
#Fulltext search: new method FT_DROP_INDEX.
@changelog_1070_li
@changelog_1079_li
#The optimization to group using an index didn't work in some cases in version 1.1 (see also system property h2.optimizeGroupSorted).
@changelog_1071_li
@changelog_1080_li
#OSGi meta data is included in the manifest file. An OSGi BundleActivator is included: it loads the database driver when starting the bundle, and unloads it when stopping the bundle.
@changelog_1072_li
@changelog_1081_li
#The default value for MAX_MEMORY_UNDO is now 50000.
@changelog_1073_li
@changelog_1082_li
#For alias columns, ResultSetMetaData.getTableName() and getColumnName() now return the real table and column name in the default mode.
@changelog_1074_li
@changelog_1083_li
#In SQL scripts created with SCRIPT TO, schemas are now only created if they don't exist yet.
@changelog_1075_li
@changelog_1084_li
#After re-connecting to a database, the database event listener (if set) is informed about it.
@changelog_1076_li
@changelog_1085_li
#Local temporary tables now support indexes. Thanks a lot to Matt Roy!
@changelog_1077_li
@changelog_1086_li
#RUNSCRIPT no longer uses a temporary file.
@changelog_1078_li
@changelog_1087_li
#New system table INFORMATION_SCHEMA.SESSION_STATE containing the SQL statements that make up the session state. The list currently contains variables (SET @..) and local temporary tables (without data).
@changelog_1079_li
@changelog_1088_li
#After an automatic re-connect, part of the session state stays (the part that is stored in the SESSION_STATE table).
@changelog_1080_li
@changelog_1089_li
#The build didn't work if the directory temp didn't exist before.
@changelog_1081_li
@changelog_1090_li
#New system property h2.maxReconnect (default 3) to limit the number of re-connects for the same SQL statement (this is usually only important for SHUTDOWN).
@changelog_1082_li
@changelog_1091_li
#WHERE .. IN (SELECT ...) could throw a NullPointerException.
@changelog_1083_li
@changelog_1092_li
#Improved Glassfish / Toplink support in H2Platform thanks to Marcio Borges from Brazil. Thanks a lot!
@changelog_1084_h2
@changelog_1093_h2
#Version 1.1.100 (2008-10-04)
@changelog_1085_li
@changelog_1094_li
#In version 1.1, the following system properties are now enabled by default: h2.lobFilesInDirectories, h2.optimizeGroupSorted, h2.optimizeInJoin, h2.shareLinkedConnections
@changelog_1086_li
@changelog_1095_li
#The H2 Console tool now works with the JDBC-ODBC bridge.
@changelog_1087_li
@changelog_1096_li
#The H2 Console tool now supports command line options to start things separately.
@changelog_1088_li
@changelog_1097_li
#Large objects did not work for in-memory databases in server mode in Linux.
@changelog_1089_li
@changelog_1098_li
#Connections from a local address other than 'localhost' were not allowed if remote connections were disabled. This was always a problem, but only got visible in the last release because the server no longer connects to 'localhost' if networked.
@changelog_1090_li
@changelog_1099_li
#The h2console.war can now be built using the Java build.
@changelog_1091_li
@changelog_1100_li
#By default, databases are shared in the same process. For read-only databases this causes unnecessary synchronization, but safes memory. If you want that each connection opens its own database, append ;OPEN_NEW=TRUE to the database URL.
@changelog_1092_li
@changelog_1101_li
#New auto-reconnect feature will cause the JDBC driver to reconnect to the database if the connection is lost. To enable, append ;AUTO_RECONNECT=TRUE to the database URL. This is specially helpful when using AUTO_SERVER. AUTO_SERVER automatically uses auto-reconnect.
@changelog_1093_li
@changelog_1102_li
#CreateCluster: the property 'serverlist' is now called 'serverList'.
@changelog_1094_li
@changelog_1103_li
#The ConvertTraceFile tool could not parse some files because the trace mechanism did not encode prepared statement parameters.
@changelog_1095_li
@changelog_1104_li
#Databases names can now be one character long (the minimum size used to be 2 characters).
@changelog_1096_h2
@changelog_1105_h2
#Version 1.0.79 (2008-09-26)
@changelog_1097_li
@changelog_1106_li
#Linked tables that point to the same database can now share the connection within the same database. Access to the same connection is serialized. To enable this feature, set the system property h2.shareLinkedConnections to true.
@changelog_1098_li
@changelog_1107_li
#Multiple processes can now access the same database without having to explicitly start the server. To do that, append ;AUTO_SERVER=TRUE to the database URL. In this case, the server is started automatically if the connection is in embedded mode, and the server mode is used if a server is running. If the process that opened the first connection is closed, the other client need to reconnect (there is no automatic re-connect so far). Remote connections are allowed, but only to this database.
@changelog_1099_li
@changelog_1108_li
#The server tool now displays the correct IP address if networked.
@changelog_1100_li
@changelog_1109_li
#Can now start a TCP server with port 0 (automatically select a port).
@changelog_1101_li
@changelog_1110_li
#Result sets with just a unique index can now be updated (previously a primary key was required).
@changelog_1102_li
@changelog_1111_li
#LINKED TABLE: the schema name can now be set. When multiple tables exist in different schema, and the schema name is not set, an exception is thrown.
@changelog_1103_li
@changelog_1112_li
#LINKED TABLE: worked around a bug in Oracle with the CHAR data type.
@changelog_1104_li
@changelog_1113_li
#Faster hash code calculation for large binary arrays.
@changelog_1105_li
@changelog_1114_li
#Faster storage re-use algorithm thanks to Greg Dhuse from cleversafe.com.
@changelog_1106_li
@changelog_1115_li
#The database supports the SHOW command for better MySQL and PostgreSQL compatibility.
@changelog_1107_li
@changelog_1116_li
#The H2 Console now abbreviates large texts in results.
@changelog_1108_li
@changelog_1117_li
#Multiple UNION queries could not be used in derived tables.
@changelog_1109_li
@changelog_1118_li
#Linked tables can now be read-only.
@changelog_1110_li
@changelog_1119_li
#Temporary linked tables are now supported.
@changelog_1111_li
@changelog_1120_li
#It was possible to create tables in read-only databases.
@changelog_1112_li
@changelog_1121_li
#SET SCHEMA_SEARCH_PATH is now documented.
@changelog_1113_li
@changelog_1122_li
#SET SCHEMA did not work for views.
@changelog_1114_li
@changelog_1123_li
#Row level locking for MVCC is now enabled. The exception 'Concurrent update in table ...' is still thrown, but only after the lock timeout.
@changelog_1115_li
@changelog_1124_li
#The maximum log file size setting was ignored for large databases.
@changelog_1116_li
@changelog_1125_li
#Multi-Version Concurrency (MVCC) may no longer be used when using the multi-threaded kernel feature (MULTI_THREADED). An exception is thrown when trying to connect with both settings. Additional synchronization is required before those features can be used together.
@changelog_1117_li
@changelog_1126_li
#The data type JAVA_OBJECT could not be used in updatable result sets.
@changelog_1118_li
@changelog_1127_li
#The system property h2.optimizeInJoin did not work correctly.
@changelog_1119_li
@changelog_1128_li
#Conditions such as ID=? AND ID>? were slow.
@changelog_1120_h2
@changelog_1129_h2
#Version 1.0.78 (2008-08-28)
@changelog_1121_li
@changelog_1130_li
#The documentation no longer uses a frameset (except the Javadocs).
@changelog_1122_li
@changelog_1131_li
#When using DB_CLOSE_DELAY, sometimes a NullPointerException is thrown when the database is opened almost at the same time as it is closed automatically. Thanks a lot to Dmitry Pekar for finding this!
@changelog_1123_li
@changelog_1132_li
#Java methods with variable number of parameters can now be used (for Java 1.5 or newer).
@changelog_1124_li
@changelog_1133_li
#The Japanese translation has been improved by Masahiro Ikemoto. Thanks a lot!
@changelog_1125_li
@changelog_1134_li
#The H2 Console replaced an empty user name with a single space.
@changelog_1126_li
@changelog_1135_li
#The build target 'build jarSmall' now includes the embedded database.
@changelog_1127_li
@changelog_1136_li
#JdbcDataSource now keeps the password in a char array where possible.
@changelog_1128_li
@changelog_1137_li
#ResultSet.absolute did not always work with large result sets.
@changelog_1129_li
@changelog_1138_li
#Column aliases can now be used in GROUP BY and HAVING.
@changelog_1130_li
@changelog_1139_li
#Jason Brittain has contributed MySQL date functions. Thanks a lot! They are not in the h2.jar file currently, but in src/tools/org/h2/mode/FunctionsMySQL.java. To install, add this class to the classpath and call FunctionsMySQL.register(conn) in the Java code.
@changelog_1131_h2
@changelog_1140_h2
#Version 1.0.77 (2008-08-16)
@changelog_1132_li
@changelog_1141_li
#JaQu is now using prepared statements and supports Date, Time, Timestamp.
@changelog_1133_li
@changelog_1142_li
#When using remote in-memory databases, large LOB objects did not work.
@changelog_1134_li
@changelog_1143_li
#Timestamp columns such as TIMESTAMP(6) were not compatible to other database.
@changelog_1135_li
@changelog_1144_li
#Opening a large database was slow if there was a problem opening the previous time.
@changelog_1136_li
@changelog_1145_li
#NOT IN(SELECT ...) was incorrect if the subquery returns no rows.
@changelog_1137_li
@changelog_1146_li
#CREATE TABLE AS SELECT did not work correctly in the multi-version concurrency mode.
@changelog_1138_li
@changelog_1147_li
#Support a comma before closing a list, as in: create table test(id int,)
@changelog_1139_li
@changelog_1148_li
#MySQL compatibility: linked tables had lower case column names on some systems.
@changelog_1140_li
@changelog_1149_li
#DB2 compatibility: the DB2 fetch-first-clause is supported.
@changelog_1141_li
@changelog_1150_li
#Oracle compatibility: old style outer join syntax using (+) did work correctly sometimes.
@changelog_1142_li
@changelog_1151_li
#ResultSet.setFetchSize is now supported.
@changelog_1143_li
@changelog_1152_li
#It has been reported that when using Install4j on some Linux systems and enabling the 'pack200' option, the h2.jar becomes corrupted by the install process, causing application failure. A workaround is to add an empty file h2.jar.nopack next to the h2.jar file. The reason for this problem is not known.
@changelog_1144_h2
@changelog_1153_h2
#Version 1.0.76 (2008-07-27)
@changelog_1145_li
@changelog_1154_li
#The comment of a domain (user defined data type) is now used as the default column comment when creating a column with this domain.
@changelog_1146_li
@changelog_1155_li
#Invalid database names are now detected and a better error message is thrown.
@changelog_1147_li
@changelog_1156_li
#ResultSetMetaData.getColumnClassName now returns the correct class name for BLOB and CLOB.
@changelog_1148_li
@changelog_1157_li
#Fixed the Oracle mode: Oracle allows multiple rows only where all columns of the unique index are NULL.
@changelog_1149_li
@changelog_1158_li
#There is a problem with Hibernate when using Boolean columns. A patch for Hibernate has been submitted at http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401
@changelog_1150_li
@changelog_1159_li
#ORDER BY on tableName.columnName didn't work correctly if the column name was also used as an alias.
@changelog_1151_li
@changelog_1160_li
#H2 Console: The progress display when opening a database has been improved.
@changelog_1152_li
@changelog_1161_li
#The error message when the server doesn't start has been improved.
@changelog_1153_li
@changelog_1162_li
#Key values can now be changed in updatable result sets.
@changelog_1154_li
@changelog_1163_li
#Changes in updatable result sets are now visible even when resetting the result set.
@changelog_1155_li
@changelog_1164_li
#Temporary files were sometimes deleted too late when executing large insert, update, or delete operations.
@changelog_1156_li
@changelog_1165_li
#The database file was growing after deleting many rows, and after large update operations.
@changelog_1157_h2
@changelog_1166_h2
#Version 1.0.75 (2008-07-14)
@changelog_1158_li
@changelog_1167_li
#Multi version concurrency (MVCC): when a row was updated or deleted, but this change was rolled back, the row was not visible by other sessions if no index was used to access it. Fixed.
@changelog_1159_li
@changelog_1168_li
#Views with multiple joined tables (where one was an outer join) couldn't be used in some cases. Fixed.
@changelog_1160_li
@changelog_1169_li
#The CSVREAD method did not process NULL correctly when using a whitespace field separator.
@changelog_1161_li
@changelog_1170_li
#Fixed the Oracle mode: Oracle allows multiple rows with NULL in a unique index.
@changelog_1162_li
@changelog_1171_li
#Running out of memory could result in incomplete transactions or corrupted databases. Fixed.
@changelog_1163_li
@changelog_1172_li
#When using order by in a query that uses the same table multiple times, the order could be incorrect. Fixed.
@changelog_1164_li
@changelog_1173_li
#Referential constraint checking improvement: now the constraint is only checked if the key column values change.
@changelog_1165_li
@changelog_1174_li
#Some database metadata calls returned the wrong data type for DATA_TYPE columns.
@changelog_1166_li
@changelog_1175_li
#The Lucene fulltext index was empty when opening a database with fulltext index enabled, and re-indexing it didn't work. Fixed.
@changelog_1167_li
@changelog_1176_li
#The character '$' could not be used in identifier names (table name, column names and so on). Fixed.
@changelog_1168_li
@changelog_1177_li
#The new method org.h2.tools.Server.startWebServer(conn) starts the H2 Console to inspect a database while debugging.
@changelog_1169_li
@changelog_1178_li
#Stopping a WebServer didn't always work. Fixed.
@changelog_1170_h2
@changelog_1179_h2
#Version 1.0.74 (2008-06-21)
@changelog_1171_li
@changelog_1180_li
#Work on row level locking has been started (but there is nothing usable yet).
@changelog_1172_li
@changelog_1181_li
#JaQu (Java Query), a tool similar to LINQ (Language Integrated Query; from Microsoft) is now included under src/tools/org/h2/jaqu. A small sample application is included under src/test/org/h2/test/jaqu.
@changelog_1173_li
@changelog_1182_li
#The source code is now switched to Java 1.6 by default. To switch back to Java 1.4, run 'build compile'. The h2.jar file is still Java 1.4.
@changelog_1174_li
@changelog_1183_li
#The ChangePassword tool is now called ChangeFileEncryption.
@changelog_1175_li
@changelog_1184_li
#It is no longer allowed to create columns with the data type NULL. Also, it is no longer allowed to convert a column to the data type NULL. This was possible before but caused data loss.
@changelog_1176_li
@changelog_1185_li
#When using computed columns or default values with a different data type than the column data type, a class cast exception could occur. Fixed.
@changelog_1177_li
@changelog_1186_li
#Opening databases larger than 1 GB was sometimes very slow if a lot of data was deleted previously. Fixed.
@changelog_1178_li
@changelog_1187_li
#RUNSCRIPT could throw a NullPointerException if the script name was an expression.
@changelog_1179_li
@changelog_1188_li
#Improved compatibility. New compatibility modes for Oracle and Derby. New compatibility flag uniqueIndexNullDistinct to only allow one row with 'NULL' in a unique index. This flag is enabled for Derby, Oracle, MSSQLServer, and HSQLDB.
@changelog_1180_li
@changelog_1189_li
#Linked tables: To view the statements that are executed against the target table, set the trace level to 3.
@changelog_1181_li
@changelog_1190_li
#RunScript tool: new options to show and check the results of queries.
@changelog_1182_li
@changelog_1191_li
#Deadlocks are now detected. One transaction is rolled back automatically.
@changelog_1183_li
@changelog_1192_li
#The Lucene fulltext index was always re-created when opening a database with fulltext index enabled.
@changelog_1184_li
@changelog_1193_li
#Support for overloaded Java methods. A user defined function can now be bound to multiple Java methods, if the Java methods have the same name but a different number of parameters. Thanks to Gary Tong for providing a patch!
@changelog_1185_h2
@changelog_1194_h2
#Version 1.0.73 (2008-05-31)
@changelog_1186_li
@changelog_1195_li
#ParameterMetaData now returns the right data type for most conditions, as in WHERE ID=?.
@changelog_1187_li
@changelog_1196_li
#The table SYSTEM_RANGE now supports expressions and parameters.
@changelog_1188_li
@changelog_1197_li
#New column INFORMATION_SCHEMA.CONSTRAINTS.UNIQUE_INDEX_NAME that contains the name of the unique index used to enforce this constraint, if there is such an index.
@changelog_1189_li
@changelog_1198_li
#SET QUERY_TIMEOUT and Statement.setQueryTimeout no longer commits a transaction. The same applies to SET @VARIABLE, SET LOCK_TIMEOUT, SET TRACE_LEVEL_*, SET THROTTLE, and SET PATH.
@changelog_1190_li
@changelog_1199_li
#The SCRIPT command does now emit IF NOT EXISTS for CREATE ROLE.
@changelog_1191_li
@changelog_1200_li
#MySQL compatibility: auto_increment column are no longer automatically converted to primary key columns.
@changelog_1192_li
@changelog_1201_li
#PostgreSQL compatibility: support for BOOL_OR and BOOL_AND aggregate functions.
@changelog_1193_li
@changelog_1202_li
#Negative scale values for DECIMAL or NUMBER columns are now supported in regular tables and in linked tables.
@changelog_1194_li
@changelog_1203_li
#A role or right can now be granted or revoked multiple times without getting an exception.
@changelog_1195_li
@changelog_1204_li
#Infinite numbers in SQL scripts are listed as POWER(0, -1)), negative infinite as (-POWER(0, -1)), and NaN (not a number) as SQRT(-1).
@changelog_1196_li
@changelog_1205_li
#The special double and float values 'NaN' (not a number) did not work correctly when sorting or comparing.
@changelog_1197_li
@changelog_1206_li
#The fulltext search did not support CLOB data types.
@changelog_1198_li
@changelog_1207_li
#If the drive with the database files was disconnected or unmounted while writing, sometimes a stack overflow exception was thrown instead of a IO exception.
@changelog_1199_li
@changelog_1208_li
#The H2 Console could not be shut down from within the tool if the browser supports keepAlive (most browsers do).
@changelog_1200_li
@changelog_1209_li
#If the password was passed as a char array, it was kept in an internal buffer longer than required. Theoretically the password could have been stolen if the main memory was swapped to disk before the garbage collection was run.
@changelog_1201_h2
@changelog_1210_h2
#Version 1.0.72 (2008-05-10)
@changelog_1202_li
@changelog_1211_li
#Some databases could not be opened when appending ;RECOVER=1 to the database URL.
@changelog_1203_li
@changelog_1212_li
#The Japanese translation of the error messages and the H2 Console has been completed by Masahiro Ikemoto (Arizona Design Inc.)
@changelog_1204_li
@changelog_1213_li
#Updates made to updatable rows are now visible within the same result set. DatabaseMetaData.ownUpdatesAreVisible now returns true.
@changelog_1205_li
@changelog_1214_li
#ParameterMetaData now returns the correct data for INSERT and UPDATE statements.
@changelog_1206_li
@changelog_1215_li
#H2 Shell: DESCRIBE now supports an schema name.
@changelog_1207_li
@changelog_1216_li
#A subset of the PostgreSQL 'dollar quoting' feature is now supported.
@changelog_1208_li
@changelog_1217_li
#SLF4J is now supported by using adding TRACE_LEVEL_FILE=4 to the database URL.
@changelog_1209_li
@changelog_1218_li
#The recovery tool did not work if the table name contained spaces or if there was a comment on the table.
@changelog_1210_li
@changelog_1219_li
#Triggers are no longer executed when changing the table structure (ALTER TABLE).
@changelog_1211_li
@changelog_1220_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.
@changelog_1212_li
@changelog_1221_li
#Statements can now be canceled remotely (when using remote connections).
@changelog_1213_li
@changelog_1222_li
#The Shell tool now uses java.io.Console to read the password when using JDK 1.6
@changelog_1214_li
@changelog_1223_li
#When using read-only databases and setting LOG=2, an exception was written to the trace file when closing the database. Fixed.
@changelog_1215_h2
@changelog_1224_h2
#Version 1.0.71 (2008-04-25)
@changelog_1216_li
@changelog_1225_li
#H2 is now dual-licensed under the Eclipse Public License (EPL) and the old 'H2 License' (which is basically MPL).
@changelog_1217_li
@changelog_1226_li
#Sometimes an exception 'File ID mismatch' or 'try to add a record twice' occurred after large records (8 KB or larger) are updated or deleted. See also http://code.google.com/p/h2database/issues/detail?id=22
@changelog_1218_li
@changelog_1227_li
#H2 Console: The tools can now be translated (it didn't work in the last release).
@changelog_1219_li
@changelog_1228_li
#New traditional Chinese translation. Thanks a lot to Derek Chao!
@changelog_1220_li
@changelog_1229_li
#Indexes were not used when enabling the optimization for IN(SELECT...) (system property h2.optimizeInJoin).
@changelog_1221_h2
@changelog_1230_h2
#Version 1.0.70 (2008-04-20)
@changelog_1222_li
@changelog_1231_li
#The plan is to dual-license H2. The additional license is EPL (Eclipse Public License). The current license (MPL, Mozilla Public License) will stay. Current users are not affected because they can keep MPL. EPL is very similar to MPL, the only bigger difference is related to patents (EPL is a bit more business friendly in this regard). See also http://opensource.org/licenses/eclipse-1.0.php, http://www.eclipse.org/legal/eplfaq.php (FAQ), http://blogs.zdnet.com/Burnette/?p=131
@changelog_1223_li
@changelog_1232_li
#Multi version concurrency (MVCC): when a row was updated, and the updated column was not indexed, this update was visible sometimes for other sessions even if it was not committed.
@changelog_1224_li
@changelog_1233_li
#Calling SHUTDOWN on one connection and starting a query on another connection concurrently could result in a Java level deadlock.
@changelog_1225_li
@changelog_1234_li
#New system property h2.enableAnonymousSSL (default: true) to enable anonymous SSL connections.
@changelog_1226_li
@changelog_1235_li
#The precision if SUBSTR is now calculated if possible.
@changelog_1227_li
@changelog_1236_li
#The autocomplete in the H2 Console has been improved a bit.
@changelog_1228_li
@changelog_1237_li
#The tools in the H2 Console are now translatable.
@changelog_1229_li
@changelog_1238_li
#The servlet and lucene jar files are now automatically downloaded when building.
@changelog_1230_li
@changelog_1239_li
#The code switch tool has been replaced by a simpler tool called SwitchSource that just uses find and replace.
@changelog_1231_li
@changelog_1240_li
#Started to write a Ant replacement ('JAnt') that uses pure Java build definitions. Advantages: ability to debug the build, extensible, flexible, no XML, a bit faster. Future plan: support creating custom h2 distributions (for embedded use). Maybe create a new project 'Jant' or 'Javen' if other people are interested.
@changelog_1232_li
@changelog_1241_li
#The jar file is now about 10% smaller because the variable debugging info is no longer included. The source file and line number debugging info is still included. If required, the jar file size of the full version can be further reduced to about 720 KB using 'build jarSmall' or even more by removing unneeded components.
@changelog_1233_li
@changelog_1242_li
#Added shell scripts run.sh and build.sh. chmod +x is required, but otherwise it should work. Feedback or improvements are welcome!
@changelog_1234_li
@changelog_1243_li
#Databases in zip files: large queries are now supported. Temp files are created in the temp directory if required. The documentation how to create the zip file has been corrected.
#The Japanese translation of the error messages and the H2 Console has been improved. Thanks a lot to Masahiro IKEMOTO.
@changelog_1237_li
@changelog_1246_li
#Optimization for MIN() and MAX() when using MVCC.
@changelog_1238_li
@changelog_1247_li
#To protect against remote brute force password attacks, the delay after each unsuccessful login now gets double as long. New system properties h2.delayWrongPasswordMin and h2.delayWrongPasswordMax.
@changelog_1239_li
@changelog_1248_li
#After setting the query timeout and then resetting it, the next query would still timeout. Fixed.
@changelog_1240_li
@changelog_1249_li
#Adding a IDENTITY column to a table with data threw a lock timeout.
@changelog_1241_li
@changelog_1250_li
#OutOfMemoryError could occur when using EXISTS or IN(SELECT ..).
@changelog_1242_li
@changelog_1251_li
#The built-in connection pool is not called JdbcConnectionPool. The API and documentation has been changed.
@changelog_1243_li
@changelog_1252_li
#The ConvertTraceFile tool now generates SQL statement statistics at the end of the SQL script file (similar to the profiling data generated when using java -Xrunhprof).
@changelog_1244_li
@changelog_1253_li
#Nested joins are now supported (A JOIN B JOIN C ON .. ON ..)
@changelog_1245_h2
@changelog_1254_h2
#Version 1.0.69 (2008-03-29)
@changelog_1246_li
@changelog_1255_li
#Most command line tools can now be called from within the H2 Console.
@changelog_1247_li
@changelog_1256_li
#A new Shell tools is now included (org.h2.tools.Shell) to query a database from the command line.
@changelog_1248_li
@changelog_1257_li
#The command line options in the tools have changed: instead of '-log true' now '-trace' is used. Also, '-ifExists', '-tcpSSL' and '-tcpAllowOthers' and so on have changed: now the 'true' is no longer needed. The old behavior is still supported.
@changelog_1249_li
@changelog_1258_li
#New system property h2.sortNullsHigh to invert the default sorting behavior for NULL. The default didn't change.
@changelog_1250_li
@changelog_1259_li
#Performance was very slow when using LOG=2 and deleting or updating all rows of a table in a loop. Fixed.
@changelog_1251_li
@changelog_1260_li
#ALTER TABLE or CREATE TABLE now support parameters for the password field.
@changelog_1252_li
@changelog_1261_li
#The linear hash has been removed. It was always slower than the b-tree index, and there were some bugs that would be hard to fix.
@changelog_1253_li
@changelog_1262_li
#TRACE_LEVEL_ settings are no longer persistent. This was a problem when database initialization code caused a lot of trace output.
@changelog_1254_li
@changelog_1263_li
#Fulltext search (native implementation): The words table is no longer an in-memory table because this caused memory problems in some cases.
@changelog_1255_li
@changelog_1264_li
#It was possible to create a role with the name as an existing user (but not vice versa). This is not allowed any more.
@changelog_1256_li
@changelog_1265_li
#The recovery tool didn't work correctly for tables without rows.
@changelog_1257_li
@changelog_1266_li
#For years below 1, the YEAR method didn't return the correct value, and the conversion from date and timestamp to varchar was incorrect.
@changelog_1258_li
@changelog_1267_li
#CSVWRITE caused a NullPointerException when not specifying a nullString.
@changelog_1259_li
@changelog_1268_li
#When a log file switch occurred just after a truncate table or drop table statement, the database could not be started normally (RECOVER=1 was required). Fixed.
@changelog_1260_li
@changelog_1269_li
#When a log file switch occurred in the middle of a sequence flush (sequences are only flushed every 32 values by default), the sequence value was lost. Fixed.
@changelog_1261_li
@changelog_1270_li
#Altering a sequence didn't unlock the system table when autocommit switched off.
@changelog_1262_h2
@changelog_1271_h2
#Version 1.0.68 (2008-03-18)
@changelog_1263_li
@changelog_1272_li
#Very large SELECT DISTINCT and UNION EXCEPT queries are now supported, however this feature is disabled by default. To enable it, set the system property h2.maxMemoryRowsDistinct to a lower value, for example 10000.
@changelog_1264_li
@changelog_1273_li
#A error is now thrown when trying to call a method inside a trigger that implicitly commits the current transaction, if an object is locked.
@changelog_1265_li
@changelog_1274_li
#Unused LOB files were deleted much too late. Now they are deleted if no longer referenced in memory.
@changelog_1266_li
@changelog_1275_li
#ALTER SEQUENCE and ALTER TABLE ALTER COLUMN RESTART can now be used inside a transaction.
@changelog_1267_li
@changelog_1276_li
#New system property h2.aliasColumnName. When enabled, aliased columns (as in SELECT ID AS I FROM TEST) return the real table and column name in ResultSetMetaData.getTableName() and getColumnName(). This is disabled by default for compatibility with other databases (HSQLDB, Apache Derby, PostgreSQL, some version of MySQL). In version 1.1 this setting will be enabled.
@changelog_1268_li
@changelog_1277_li
#When using encrypted databases, and using the wrong file password, the log file was renamed if the database was not already open. Fixed.
@changelog_1269_li
@changelog_1278_li
#Improved performance when using lob files in directories (however this is still disabled by default)
@changelog_1270_li
@changelog_1279_li
#H2 Console: autocomplete didn't work with very large scripts. Fixed.
@changelog_1271_li
@changelog_1280_li
#Fulltext search: new method SEARCH_DATA that returns the column names and primary keys as arrays.
@changelog_1272_li
@changelog_1281_li
#New experimental optimization for GROUP BY queries if an index can be used that matches the group by columns. To enable this optimization, set the system property h2.optimizeGroupSorted to true.
@changelog_1273_li
@changelog_1282_li
#When using multi-version concurrency (MVCC=TRUE), duplicate rows could appear in the result set when running queries with uncommitted changes in the same session.
@changelog_1274_li
@changelog_1283_li
#H2 Console: remote connections were very slow because getHostName/getRemoteHost was used. Fixed (now using getHostAddress/getRemoteAddr.
@changelog_1275_li
@changelog_1284_li
#H2 Console: on Linux, Firefox, Konqueror, or Opera (in this order) are now started if available. This has been tested on Ubuntu.
@changelog_1276_li
@changelog_1285_li
#H2 Console: the start window works better with IKVM
@changelog_1277_li
@changelog_1286_li
#H2 Console: improved compatibility with Safari (Safari requires keep-alive)
@changelog_1278_li
@changelog_1287_li
#Random: the process didn't stop if generating the random seed using the standard way (SecureRandom.generateSeed) was very slow. Now using a daemon thread to avoid this problem.
@changelog_1279_li
@changelog_1288_li
#SELECT UNION with a different number of ORDER BY columns did throw an ArrayIndexOutOfBoundsException.
@changelog_1280_li
@changelog_1289_li
#When using a view, the column precision was changed to the default scale for some data types.
@changelog_1281_li
@changelog_1290_li
#CSVWRITE now supports a 'null string' that is used for parsing and writing NULL.
@changelog_1282_li
@changelog_1291_li
#Some long running queries could not be canceled.
@changelog_1283_li
@changelog_1292_li
#Queries with many outer join tables were very slow. Fixed.
@changelog_1284_li
@changelog_1293_li
#The performance of text comparison has been improved when using locale sensitive string comparison (SET COLLATOR). Now CollationKey is used with a LRU cache. The default cache size is 10000, and can be changed using the system property h2.collatorCacheSize. Use 0 to disable the cache.
@changelog_1285_li
@changelog_1294_li
#UPDATE SET column=DEFAULT is now supported.
@changelog_1286_h2
@changelog_1295_h2
#Version 1.0.67 (2008-02-22)
@changelog_1287_li
@changelog_1296_li
#New function FILE_READ to read a file or from an URL. Both binary and text data is supported.
@changelog_1288_li
@changelog_1297_li
#CREATE TABLE AS SELECT now supports specifying the column list and data types.
@changelog_1289_li
@changelog_1298_li
#Connecting to a TCP server and at shutting it down at the same time could cause a Java level deadlock.
@changelog_1290_li
@changelog_1299_li
#A user now has all rights on his own local temporary tables.
@changelog_1291_li
@changelog_1300_li
#The CSV tool now supports a custom lineSeparator.
@changelog_1292_li
@changelog_1301_li
#When using multiple connections, empty space was reused too early sometimes. This could corrupt the database when recovering.
@changelog_1293_li
@changelog_1302_li
#The H2 Console has been translated to Dutch. Thanks a lot to Remco Schoen!
@changelog_1294_li
@changelog_1303_li
#Databases can now be opened even if trigger classes are not in the classpath. The exception is thrown when trying to fire the trigger.
@changelog_1295_li
@changelog_1304_li
#Opening databases with ACCESS_MODE_DATA=r is now supported. In this case the database is read-only, but the files don't not need to be read-only.
@changelog_1296_li
@changelog_1305_li
#Security: The database now waits 200 ms before throwing an exception if the user name or password don't match, to slow down dictionary attacks.
@changelog_1297_li
@changelog_1306_li
#The value cache is now a soft reference cache. This should help save memory.
@changelog_1298_li
@changelog_1307_li
#CREATE INDEX on a table with many rows could run out of memory. Fixed.
@changelog_1299_li
@changelog_1308_li
#Large result sets are now a bit faster.
@changelog_1300_li
@changelog_1309_li
#ALTER TABLE ALTER COLUMN RESTART and ALTER SEQUENCE now support parameters (any expressions).
@changelog_1301_li
@changelog_1310_li
#When setting the base directory on the command line, the user directory prefix ('~') was ignored.
@changelog_1302_li
@changelog_1311_li
#The DbStarter servlet didn't start the TCP listener even if configured.
@changelog_1303_li
@changelog_1312_li
#Statement.setQueryTimeout() is now supported.
@changelog_1304_li
@changelog_1313_li
#New session setting QUERY_TIMEOUT, and new system property h2.maxQueryTimeout.
@changelog_1305_li
@changelog_1314_li
#Changing the transaction log level (SET LOG) is now written to the trace file by default.
@changelog_1306_li
@changelog_1315_li
#In a SQL script, primary key constraints are now ordered before foreign key constraints.
@changelog_1307_li
@changelog_1316_li
#It was not possible to create a referential constraint to a table in a different schema in some situations.
@changelog_1308_li
@changelog_1317_li
#The H2 Console was slow when the database contains many tables. Now the column names are not shown in this case.
@changelog_1309_h2
@changelog_1318_h2
#Version 1.0.66 (2008-02-02)
@changelog_1310_li
@changelog_1319_li
#There is a new online error analyzer tool.
@changelog_1311_li
@changelog_1320_li
#H2 Console: stack traces are now links to the source code in the source repository (H2 database only).
@changelog_1312_li
@changelog_1321_li
#CHAR data type equals comparison was case insensitive instead of case sensitive.
@changelog_1313_li
@changelog_1322_li
#The exception 'Value too long for column' now includes the data.
@changelog_1314_li
@changelog_1323_li
#The table name was missing in the documentation of CREATE INDEX.
@changelog_1315_li
@changelog_1324_li
#Better support for IKVM (www.ikvm.net): the H2 Console now opens a browser window.
@changelog_1316_li
@changelog_1325_li
#The cache size was not correctly calculated for tables with large objects (specially if compression is used). This could lead to out-of-memory exceptions.
@changelog_1317_li
@changelog_1326_li
#The exception "Hexadecimal string contains non-hex character" was not always thrown when it should have been. Fixed.
@changelog_1318_li
@changelog_1327_li
#The H2 Console now provides a link to the documentation when an error occurs (H2 databases only so far).
@changelog_1319_li
@changelog_1328_li
#The acting as PostgreSQL server, when a base directory was set, and the H2 Console was started as well, the base directory was applied twice.
@changelog_1320_li
@changelog_1329_li
#Calling EXTRACT(HOUR FROM ...) or EXTRACT(HH FROM ...) returned the wrong values (0 to 11 instead of 0 to 23). All other tested databases return values from 0 to 23. Please check if your application relies on the old behavior before upgrading.
@changelog_1321_li
@changelog_1330_li
#For compatibility with other databases the column default (COLUMN_DEF) for columns without default is now null (it was an empty string).
@changelog_1322_li
@changelog_1331_li
#Statements that contain very large subqueries (where the subquery result does not fit in memory) are now faster.
@changelog_1323_li
@changelog_1332_li
#Variables: large objects (CLOB and BLOB) that don't fit in memory did not work correctly when used as variables.
@changelog_1324_li
@changelog_1333_li
#Fulltext search is now supported in named in-memory databases.
@changelog_1325_li
@changelog_1334_li
#H2 Console: multiple consecutive spaces in the setting name did not work. Fixed.
@changelog_1326_h2
@changelog_1335_h2
#Version 1.0.65 (2008-01-18)
@changelog_1327_li
@changelog_1336_li
#The build (ant) now automatically switches the source code to the correct version (JDK 1.4/1.5 or 1.6).
@changelog_1328_li
@changelog_1337_li
#A recovery bug has been fixed. With older versions, it was necessary to add ;RECOVER=1 to the database URL in cases where it should not have been required.
@changelog_1329_li
@changelog_1338_li
#The performance for DROP and DROP ALL OBJECTS has been improved.
@changelog_1330_li
@changelog_1339_li
#The ChangePassword API has been improved.
@changelog_1331_li
@changelog_1340_li
#User defined variables are now supported. Examples: SET @VAR=10;CALL @VAR. This can be used for running totals as in: select x, set(@t, ifnull(@t, 0) + x) from system_range(1, 10)
@changelog_1332_li
@changelog_1341_li
#The Ukrainian translation has been improved.
@changelog_1333_li
@changelog_1342_li
#CALL statements can now be used in batch updates and called using Statement.executeUpdate.
@changelog_1334_li
@changelog_1343_li
#New read-only setting CREATE_BUILD (the build number of the database engine that created the database).
@changelog_1335_li
@changelog_1344_li
#The optimizer did not use multi column indexes for range queries in some cases. Fixed.
@changelog_1336_li
@changelog_1345_li
#The H2 Console now calls DataSource.getConnection() instead of DataSource.getConnection(user, password) when user name and password are not specified.
@changelog_1337_li
@changelog_1346_li
#The bind IP address can now be set when using multi-homed host (if multiple network adapters are available) using the system property h2.bindAddress.
@changelog_1338_li
@changelog_1347_li
#Batch update: Calling BatchUpdateException.printStackTrace() could result in out of memory. Fixed.
@changelog_1339_li
@changelog_1348_li
#Indexes of unique or foreign constraints where not dropped when the constraint was dropped after altering the table (for example dropping a column). Fixed.
@changelog_1340_li
@changelog_1349_li
#The performance for large result sets in the server mode has been improved.
@changelog_1341_li
@changelog_1350_li
#The setting h2.serverSmallResultSetSize has been renamed to h2.serverResultSetFetchSize.
@changelog_1342_li
@changelog_1351_li
#The SCRIPT command now uses multi-row insert statements to save space except if the option SIMPLE is used.
@changelog_1343_li
@changelog_1352_li
#The SCRIPT command did not split up CLOB data correctly. Fixed.
@changelog_1344_li
@changelog_1353_li
#Optimization for single column distinct queries with an index: select distinct name from test. Can be disabled by setting the system property h2.optimizeDistinct to false.
@changelog_1345_li
@changelog_1354_li
#DROP ALL OBJECTS did not drop user defined aggregate functions and domains.
@changelog_1346_li
@changelog_1355_li
#PostgreSQL compatibility: COUNT(T.*) is now supported.
@changelog_1347_li
@changelog_1356_li
#LIKE comparisons are now faster.
@changelog_1348_li
@changelog_1357_li
#Encrypted databases are now faster.
@download_1000_h1
...
...
@@ -5617,45 +5644,51 @@ Sourceファイル
#Platform for developing multiuser applications and games with Macromedia Flash.
@links_1175_a
#StorYBook
#SQLOrm
@links_1176_p
#A summary-based tool for novelist and script writers. It helps to keep the overview over the various traces a story has.
#Java Object Relation Mapping.
@links_1177_a
#StreamCruncher
#StorYBook
@links_1178_p
#Event (stream) processing kernel.
#A summary-based tool for novelist and script writers. It helps to keep the overview over the various traces a story has.
@links_1179_a
#Tune Backup
#StreamCruncher
@links_1180_p
#Easy-to-use backup solution for your iTunes library.
#Event (stream) processing kernel.
@links_1181_a
#weblica
#Tune Backup
@links_1182_p
#Desktop CMS.
#Easy-to-use backup solution for your iTunes library.
@links_1183_a
#Web of Web
#weblica
@links_1184_p
#Collaborative and realtime interactive media platform for the web.
#Desktop CMS.
@links_1185_a
#Werkzeugkasten
#Web of Web
@links_1186_p
#Minimum Java Toolset.
#Collaborative and realtime interactive media platform for the web.
@links_1187_a
#Volunteer database
#Werkzeugkasten
@links_1188_p
#Minimum Java Toolset.
@links_1189_a
#Volunteer database
@links_1190_p
#A database front end to register volunteers, partnership and donation for a Non Profit organization.
@mainWeb_1000_h1
...
...
@@ -6912,91 +6945,103 @@ MySQL
@performance_1381_td
#87112
@performance_1382_h2
@performance_1382_p
#There are a few problems with the PolePosition test:
@performance_1383_li
#HSQLDB uses in-memory tables by default while H2 uses persistent tables. The HSQLDB version included in PolePosition does not support changing this, so you need to replace poleposition-0.20/lib/hsqldb.jar with a newer version (for example hsqldb-1.8.0.7.jar), and then use the setting hsqldb.connecturl=jdbc:hsqldb:file:data/hsqldb/dbbench2;hsqldb.default_table_type=cached;sql.enforce_size=true in Jdbc.properties.
@performance_1384_li
#HSQLDB keeps the database open between tests, while H2 closes the database (losing all the cache). To change that, use the database URL jdbc:h2:file:data/h2/dbbench;DB_CLOSE_DELAY=-1
@performance_1385_li
#The amount of cache memory is quite important, specially for the PolePosition test. Unfortunately, the PolePosition test does not take this into account.
@performance_1386_h2
#Application Profiling
@performance_1383_h3
@performance_1387_h3
#Analyze First
@performance_1384_p
@performance_1388_p
#Before trying to optimize the performance, it is important to know where the time is actually spent. The same is true for memory problems. Premature or 'blind' optimization should be avoided, as it is not an efficient way to solve the problem. There are various ways to analyze the application. In some situations it is possible to compare two implementations and use System.currentTimeMillis() to find out which one is faster. But this does not work for complex applications with many modules, and for memory problems.
@performance_1385_p
@performance_1389_p
#A very good tool to measure both the memory and the CPU is the <a href="http://www.yourkit.com">YourKit Java Profiler</a> . This tool is also used to optimize the performance and memory footprint of this database engine.
@performance_1386_p
@performance_1390_p
#A simple way to profile an application is to use the built-in profiling tool of java. Example:
@performance_1387_p
@performance_1391_p
#Unfortunately, it is only possible to profile the application from start to end.
@performance_1388_h2
@performance_1392_h2
#Database Profiling
@performance_1389_p
@performance_1393_p
#The ConvertTraceFile tool generates SQL statement statistics at the end of the SQL script file. The format used is similar to the profiling data generated when using java -Xrunhprof. As an example, execute the the following script using the H2 Console:
@performance_1390_p
@performance_1394_p
#Now convert the .trace.db file using the ConvertTraceFile tool:
@performance_1391_p
@performance_1395_p
#The generated file <code>test.sql</code> will contain the SQL statements as well as the following profiling data (results vary):
@performance_1392_h2
@performance_1396_h2
#Database Performance Tuning
@performance_1393_h3
@performance_1397_h3
#Virus Scanners
@performance_1394_p
@performance_1398_p
#Some virus scanners scan files every time they are accessed. It is very important for performance that database files are not scanned for viruses. The database engine does never interprets the data stored in the files as programs, that means even if somebody would store a virus in a database file, this would be harmless (when the virus does not run, it cannot spread). Some virus scanners allow excluding file endings. Make sure files ending with .db are not scanned.
@performance_1395_h3
@performance_1399_h3
トレースオプションを使用する
@performance_1396_p
@performance_1400_p
#If the main performance hot spots are in the database engine, in many cases the performance can be optimized by creating additional indexes, or changing the schema. Sometimes the application does not directly generate the SQL statements, for example if an O/R mapping tool is used. To view the SQL statements and JDBC API calls, you can use the trace options. For more information, see <a href="features.html#trace_options">Using the Trace Options</a> .
@performance_1397_h3
@performance_1401_h3
#Index Usage
@performance_1398_p
@performance_1402_p
#This database uses indexes to improve the performance of SELECT, UPDATE and DELETE statements. If a column is used in the WHERE clause of a query, and if an index exists on this column, then the index can be used. Multi-column indexes are used if all or the first columns of the index are used. Both equality lookup and range scans are supported. Indexes are not used to order result sets: The results are sorted in memory if required. Indexes are created automatically for primary key and unique constraints. Indexes are also created for foreign key constraints, if required. For other columns, indexes need to be created manually using the CREATE INDEX statement.
@performance_1399_h3
@performance_1403_h3
#Optimizer
@performance_1400_p
@performance_1404_p
#This database uses a cost based optimizer. For simple and queries and queries with medium complexity (less than 7 tables in the join), the expected cost (running time) of all possible plans is calculated, and the plan with the lowest cost is used. For more complex queries, the algorithm first tries all possible combinations for the first few tables, and the remaining tables added using a greedy algorithm (this works well for most joins). Afterwards a genetic algorithm is used to test at most 2000 distinct plans. Only left-deep plans are evaluated.
@performance_1401_h3
@performance_1405_h3
#Expression Optimization
@performance_1402_p
@performance_1406_p
#After the statement is parsed, all expressions are simplified automatically if possible. Operations are evaluated only once if all parameters are constant. Functions are also optimized, but only if the function is constant (always returns the same result for the same parameter values). If the WHERE clause is always false, then the table is not accessed at all.
@performance_1403_h3
@performance_1407_h3
#COUNT(*) Optimization
@performance_1404_p
@performance_1408_p
#If the query only counts all rows of a table, then the data is not accessed. However, this is only possible if no WHERE clause is used, that means it only works for queries of the form SELECT COUNT(*) FROM table.
#When executing a query, at most one index per joined table can be used. If the same table is joined multiple times, for each join only one index is used. Example: for the query SELECT * FROM TEST T1, TEST T2 WHERE T1.NAME='A' AND T2.ID=T1.ID, two index can be used, in this case the index on NAME for T1 and the index on ID for T2.
@performance_1407_p
@performance_1411_p
#If a table has multiple indexes, sometimes more than one index could be used. Example: if there is a table TEST(ID, NAME, FIRSTNAME) and an index on each column, then two indexes could be used for the query SELECT * FROM TEST WHERE NAME='A' AND FIRSTNAME='B', the index on NAME or the index on FIRSTNAME. It is not possible to use both indexes at the same time. Which index is used depends on the selectivity of the column. The selectivity describes the 'uniqueness' of values in a column. A selectivity of 100 means each value appears only once, and a selectivity of 1 means the same value appears in many or most rows. For the query above, the index on NAME should be used if the table contains more distinct names than first names.
@performance_1408_p
@performance_1412_p
#The SQL statement ANALYZE can be used to automatically estimate the selectivity of the columns in the tables. This command should be run from time to time to improve the query plans generated by the optimizer.
@performance_1409_h3
@performance_1413_h3
#Optimization Examples
@performance_1410_p
@performance_1414_p
#See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
@quickstart_1000_h1
...
...
@@ -7192,7 +7237,7 @@ SQLコマンドがコマンドエリアに表示されます。
#Option for Java functions: [DETERMINISTIC] FOR ...
@roadmap_1031_li
#Improved fulltext search (supports LOBs).
#Fulltext search: support streaming CLOB data.
@roadmap_1032_li
#Support mixed clustering mode (one embedded, the other server mode)
...
...
@@ -7573,7 +7618,7 @@ SQLコマンドがコマンドエリアに表示されます。
#Read InputStream when executing, as late as possible (maybe only embedded mode). Problem with re-execute.
@roadmap_1158_li
#Fulltext search: min word length; store word positions
#Native fulltext search: min word length; store word positions
@roadmap_1159_li
#FTP Server: Implement a client to send / receive files to server (dir, get, put)
...
...
@@ -7816,360 +7861,366 @@ SQLコマンドがコマンドエリアに表示されます。
#Support data type INTERVAL
@roadmap_1239_li
#NATURAL JOIN: MySQL and PostgreSQL don't repeat columns when using SELECT * ...
#Optimize SELECT MIN(ID), MAX(ID), COUNT(*) FROM TEST WHERE ID BETWEEN 100 AND 200
@roadmap_1240_li
#Optimize SELECT MIN(ID), MAX(ID), COUNT(*) FROM TEST WHERE ID BETWEEN 100 AND 200
#Triggers for metadata tables; use for PostgreSQL catalog
@roadmap_1268_li
#Javadoc: document design patterns used
#Does the FTP server has problems with multithreading?
@roadmap_1269_li
#Triggers for metadata tables; use for PostgreSQL catalog
#Write an article about SQLInjection (h2\src\docsrc\html\images\SQLInjection.txt)
@roadmap_1270_li
#Does the FTP server has problems with multithreading?
#Convert SQL-injection-2.txt to html document, include SQLInjection.java sample
@roadmap_1271_li
#Write an article about SQLInjection (h2\src\docsrc\html\images\SQLInjection.txt)
#Send SQL Injection solution proposal to MySQL, Derby, HSQLDB,...
@roadmap_1272_li
#Convert SQL-injection-2.txt to html document, include SQLInjection.java sample
#Improve LOB in directories performance
@roadmap_1273_li
#Send SQL Injection solution proposal to MySQL, Derby, HSQLDB,...
#Optimize OR conditions: convert them to IN(...) if possible.
@roadmap_1274_li
#Improve LOB in directories performance
#Web site design: http://www.igniterealtime.org/projects/openfire/index.jsp
@roadmap_1275_li
#Optimize OR conditions: convert them to IN(...) if possible.
#HSQLDB compatibility: Openfire server uses: CREATE SCHEMA PUBLIC AUTHORIZATION DBA; CREATE USER SA PASSWORD ""; GRANT DBA TO SA; SET SCHEMA PUBLIC
@roadmap_1276_li
#Web site design: http://www.igniterealtime.org/projects/openfire/index.jsp
#Web site: Rename Performance to Comparison [/Compatibility], move Comparison to Other Database Engines to Comparison, move Products that Work with H2 to Comparison, move Performance Tuning to Advanced Topics
@roadmap_1277_li
#HSQLDB compatibility: Openfire server uses: CREATE SCHEMA PUBLIC AUTHORIZATION DBA; CREATE USER SA PASSWORD ""; GRANT DBA TO SA; SET SCHEMA PUBLIC
#Support JMX: Create an MBean for each database and server (support JConsole). See http://thedevcloud.blogspot.com/2008/10/displaying-hsql-database-manager-in.html
@roadmap_1278_li
#Web site: Rename Performance to Comparison [/Compatibility], move Comparison to Other Database Engines to Comparison, move Products that Work with H2 to Comparison, move Performance Tuning to Advanced Topics
#Translation: use ?? in help.csv
@roadmap_1279_li
#Support JMX: Create an MBean for each database and server (support JConsole). See http://thedevcloud.blogspot.com/2008/10/displaying-hsql-database-manager-in.html
#Translated .pdf
@roadmap_1280_li
#Translation: use ?? in help.csv
#Cluster: hot deploy (adding a node at runtime)
@roadmap_1281_li
#Translated .pdf
#MySQL compatibility: update test1 t1, test2 t2 set t1.id = t2.id where t1.id = t2.id;
@roadmap_1282_li
#Cluster: hot deploy (adding a node at runtime)
#Try again with Lobo browser (pure Java)
@roadmap_1283_li
#MySQL compatibility: update test1 t1, test2 t2 set t1.id = t2.id where t1.id = t2.id;
#Recovery tool: bad blocks should be converted to INSERT INTO SYSTEM_ERRORS(...), and things should go into the .trace.db file
@roadmap_1284_li
#Try again with Lobo browser (pure Java)
#RECOVER=2 to backup the database, run recovery, open the database
@roadmap_1285_li
#Recovery tool: bad blocks should be converted to INSERT INTO SYSTEM_ERRORS(...), and things should go into the .trace.db file
#Recovery should work with encrypted databases
@roadmap_1286_li
#RECOVER=2 to backup the database, run recovery, open the database
#Corruption: new error code, add help
@roadmap_1287_li
#Recovery should work with encrypted databases
#Space reuse: after init, scan all storages and free those that don't belong to a live database object
@roadmap_1288_li
#Corruption: new error code, add help
#SysProperties: change everything to H2_...
@roadmap_1289_li
#Space reuse: after init, scan all storages and free those that don't belong to a live database object
#Use FilterIn / FilterOut putStream?
@roadmap_1290_li
#SysProperties: change everything to H2_...
#Access rights: add missing features (users should be 'owner' of objects; missing rights for sequences; dropping objects)
@roadmap_1291_li
#Use FilterIn / FilterOut putStream?
#Support NOCACHE table option (Oracle)
@roadmap_1292_li
#Access rights: add missing features (users should be 'owner' of objects; missing rights for sequences; dropping objects)
#Index usage for UPDATE ... WHERE .. IN (SELECT...)
@roadmap_1293_li
#Support NOCACHE table option (Oracle)
#Add regular javadocs (using the default doclet, but another css) to the homepage.
@roadmap_1294_li
#Index usage for UPDATE ... WHERE .. IN (SELECT...)
#The database should be kept open for a longer time when using the server mode.
@roadmap_1295_li
#Add regular javadocs (using the default doclet, but another css) to the homepage.
#Javadocs: for each tool, add a copy & paste sample in the class level.
@roadmap_1296_li
#The database should be kept open for a longer time when using the server mode.
#Javadocs: add @author tags.
@roadmap_1297_li
#Javadocs: for each tool, add a copy & paste sample in the class level.
#Fluent API for tools: Server.createTcpServer().setPort(9081).setPassword(password).start();
@roadmap_1298_li
#Javadocs: add @author tags.
#MySQL compatibility: real SQL statements for SHOW TABLES, DESCRIBE TEST (then remove from Shell)
@roadmap_1299_li
#Fluent API for tools: Server.createTcpServer().setPort(9081).setPassword(password).start();
#Use a default delay of 1 second before closing a database.
@roadmap_1300_li
#MySQL compatibility: real SQL statements for SHOW TABLES, DESCRIBE TEST (then remove from Shell)
#Maven: upload source code and javadocs as well.
@roadmap_1301_li
#Use a default delay of 1 second before closing a database.
#Write (log) to system table before adding to internal data structures.
@roadmap_1302_li
#Maven: upload source code and javadocs as well.
#Support very large deletes and updates.
@roadmap_1303_li
#Write (log) to system table before adding to internal data structures.
#Doclet (javadocs): constructors are not listed.
@roadmap_1304_li
#Support very large deletes and updates.
#Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup).
@roadmap_1305_li
#Doclet (javadocs): constructors are not listed.
#Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object);
@roadmap_1306_li
#Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup).
#MVCC should not be memory bound (uncommitted data is kept in memory in the delta index; maybe using a regular btree index solves the problem).
@roadmap_1307_li
#Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object);
#Support CREATE TEMPORARY LINKED TABLE.
@roadmap_1308_li
#MVCC should not be memory bound (uncommitted data is kept in memory in the delta index; maybe using a regular btree index solves the problem).
#MySQL compatibility: SELECT @variable := x FROM SYSTEM_RANGE(1, 50);
@roadmap_1309_li
#Support CREATE TEMPORARY LINKED TABLE.
#Oracle compatibility: support NLS_DATE_FORMAT.
@roadmap_1310_li
#MySQL compatibility: SELECT @variable := x FROM SYSTEM_RANGE(1, 50);
#Support flashback queries as in Oracle.
@roadmap_1311_li
#Oracle compatibility: support NLS_DATE_FORMAT.
#Import / Export of fixed with text files.
@roadmap_1312_li
#Support flashback queries as in Oracle.
#Support for OUT parameters in user-defined procedures.
@roadmap_1313_li
#Import / Export of fixed with text files.
#Support getGeneratedKeys to return multiple rows when used with batch updates. This is supported by MySQL, but not Derby. Both PostgreSQL and HSQLDB don't support getGeneratedKeys. Also support it when using INSERT ... SELECT.
@roadmap_1314_li
#Support for OUT parameters in user-defined procedures.
#HSQLDB compatibility: automatic data type for SUM if value is the value is too big (by default use the same type as the data).
@roadmap_1315_li
#Support getGeneratedKeys to return multiple rows when used with batch updates. This is supported by MySQL, but not Derby. Both PostgreSQL and HSQLDB don't support getGeneratedKeys. Also support it when using INSERT ... SELECT.
#Improve the optimizer to select the right index for special cases: where id between 2 and 4 and booleanColumn
@roadmap_1316_li
#HSQLDB compatibility: automatic data type for SUM if value is the value is too big (by default use the same type as the data).
#Enable warning for 'Local variable declaration hides another field or variable'.
@roadmap_1317_li
#Improve the optimizer to select the right index for special cases: where id between 2 and 4 and booleanColumn
#Linked tables: make hidden columns available (Oracle: rowid and ora_rowscn columns).
@roadmap_1318_li
#Enable warning for 'Local variable declaration hides another field or variable'.
#Support merge join.
@roadmap_1319_li
#Linked tables: make hidden columns available (Oracle: rowid and ora_rowscn columns).
#H2 Console: in-place autocomplete.
@roadmap_1320_li
#Support merge join.
#Oracle: support DECODE method (convert to CASE WHEN).
@roadmap_1321_li
#H2 Console: in-place autocomplete.
#Support large databases: split LOB (BLOB, CLOB) to multiple directories / disks (similar to tablespaces).
@roadmap_1322_li
#Oracle: support DECODE method (convert to CASE WHEN).
#Support to assign a primary key index a user defined name.
@roadmap_1323_li
#Support large databases: split LOB (BLOB, CLOB) to multiple directories / disks (similar to tablespaces).
#Cluster: Add feature to make sure cluster nodes can not get out of sync (for example by stopping one process).
@roadmap_1324_li
#Support to assign a primary key index a user defined name.
#H2 Console: support configuration option for fixed width (monospace) font.
@roadmap_1325_li
#Cluster: Add feature to make sure cluster nodes can not get out of sync (for example by stopping one process).
#Native fulltext search: support analyzers (specially for Chinese, Japanese).
@roadmap_1326_li
#H2 Console: support configuration option for fixed width (monospace) font.
#Automatically compact databases from time to time (as a background process).
@roadmap_1327_li
#Native fulltext search: support analyzers (specially for Chinese, Japanese).
#Support SCOPE_IDENTITY().
@roadmap_1328_li
#Automatically compact databases from time to time (as a background process).
#Support GRANT SELECT, UPDATE ON *.
@roadmap_1329_li
#Support SCOPE_IDENTITY().
#Test Eclipse DTP.
@roadmap_1330_li
#Support GRANT SELECT, UPDATE ON *.
#H2 Console: autocomplete: keep the previous setting
@roadmap_1331_li
#Test Eclipse DTP.
#executeBatch: option to stop at the first failed statement.
@roadmap_1332_li
#H2 Console: autocomplete: keep the previous setting
#Implement OLAP features as described here: http://www.devx.com/getHelpOn/10MinuteSolution/16573/0/page/5
@roadmap_1333_li
#executeBatch: option to stop at the first failed statement.
#Support Oracle ROWID (unique identifier for each row).
@roadmap_1334_li
#Implement OLAP features as described here: http://www.devx.com/getHelpOn/10MinuteSolution/16573/0/page/5
#Server mode: Improve performance for batch updates.
@roadmap_1335_li
#Support Oracle ROWID (unique identifier for each row).
#Applets: Support read-only databases in a zip file (accessed as a resource).
@roadmap_1336_li
#Server mode: Improve performance for batch updates.
#Long running queries / errors / trace system table.
@roadmap_1337_li
#Applets: Support read-only databases in a zip file (accessed as a resource).
#H2 Console should support JaQu directly.
@roadmap_1338_li
#Long running queries / errors / trace system table.
#Option to copy the old version of each changed page once after a checkpoint.
@roadmap_1339_li
#H2 Console should support JaQu directly.
#H2 Console: support single file upload and directory download (optional).
@roadmap_1340_li
#Option to copy the old version of each changed page once after a checkpoint.
#Document FTL_SEARCH, FTL_SEARCH_DATA.
@roadmap_1341_li
#H2 Console: support single file upload and directory download (optional).
#Support DatabaseMetaData.insertsAreDetected: updatable result sets should detect inserts.
@roadmap_1342_li
#Document FTL_SEARCH, FTL_SEARCH_DATA.
#Auto-server: add option to define the IP address range or list.
@roadmap_1343_li
#Support DatabaseMetaData.insertsAreDetected: updatable result sets should detect inserts.
#Open a read-only database but don't share it with other connections. jdbc:h2:~/test;PRIVATE=TRUE
@roadmap_1344_li
#Auto-server: add option to define the IP address range or list.
#Index creation only using deterministic functions.
@roadmap_1345_li
#Open a read-only database but don't share it with other connections. jdbc:h2:~/test;PRIVATE=TRUE
#Use http://recaptcha.net somehow to secure the Google Group.
@roadmap_1346_li
#Index creation only using deterministic functions.
#Support DELETE with TOP or LIMIT. See also: http://dev.mysql.com/doc/refman/5.1/de/delete.html
@roadmap_1347_li
#Use http://recaptcha.net somehow to secure the Google Group.
#Change the default for NULL || 'x' to return NULL
@roadmap_1348_li
#Support DELETE with TOP or LIMIT. See also: http://dev.mysql.com/doc/refman/5.1/de/delete.html
#ANALYZE: Use a bloom filter for each indexed column to estimate count of distinct values.
@roadmap_1349_li
#Change the default for NULL || 'x' to return NULL
#ANALYZE: For unique indexes that allow null, count the number of null.
@roadmap_1350_li
#ANALYZE: Use a bloom filter for each indexed column to estimate count of distinct values.
#AUTO_SERVER: support changing IP addresses (disable a network while the database is open).
@roadmap_1351_li
#ANALYZE: For unique indexes that allow null, count the number of null.
#Avoid using java.util.Calendar internally because it's slow, complicated, and seems to be buggy.
@roadmap_1352_li
#AUTO_SERVER: support changing IP addresses (disable a network while the database is open).
#Support TRUNCATE .. CASCADE like PostgreSQL.
@roadmap_1353_li
#Avoid using java.util.Calendar internally because it's slow, complicated, and seems to be buggy.
#Support opening a database that is in the classpath, maybe using a new file system.
@roadmap_1354_li
#Support TRUNCATE .. CASCADE like PostgreSQL.
#Fulltext search: lazy result generation using SimpleRowSource.
@roadmap_1355_h2
#Not Planned
@roadmap_1355_li
#Support transformation to join for user defined functions, as for IN(SELECT...).
@roadmap_1356_li
#Fulltext search: Support alternative syntax: WHERE FTL_CONTAINS(name, 'hello').
@roadmap_1357_h2
#Not Planned
@roadmap_1358_li
#HSQLDB (did) support this: select id i from test where i>0 (other databases don't). Supporting it may break compatibility.
@roadmap_1357_li
@roadmap_1359_li
#String.intern (so that Strings can be compared with ==) will not be used because some VMs have problems when used extensively.
#This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1201_p
#QUERY: "PUBLIC"."TEST" WHERE "ID"=1
@tutorial_1202_p
#To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code> . The result contains the columns SCHEMA (the schema name), TABLE (the table name), COLUMNS (an array of column names), and KEYS (an array of objects). To join a table, use a join as in: <code>SELECT T.*FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID= FT.KEYS[0];</code>
@tutorial_1203_p
Javaアプリケーション内からインデックスを呼び出すことも可能です:
@tutorial_1201_h3
@tutorial_1204_h3
Luceneフルテキストサーチを使用する
@tutorial_1202_p
@tutorial_1205_p
#To use the Lucene full text search, you need the Lucene library in the classpath. How his is done depends on the application; if you use the H2 Console, you can add the Lucene jar file to the environment variables H2DRIVERS or CLASSPATH. To initialize the Lucene full text search in a database, call:
@tutorial_1203_p
@tutorial_1206_p
#You need to initialize it in each database where you want to use it. Afterwards, you can create a full text index for a table using:
#This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1209_p
#QUERY: "PUBLIC"."TEST" WHERE "ID"=1
@tutorial_1210_p
#To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code> . The result contains the columns SCHEMA (the schema name), TABLE (the table name), COLUMNS (an array of column names), and KEYS (an array of objects). To join a table, use a join as in: <code>SELECT T.*FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID= FT.KEYS[0];</code>
@tutorial_1211_p
Javaアプリケーション内からインデックスを呼び出すことも可能です:
@tutorial_1206_h2
@tutorial_1212_h2
#User-Defined Variables
@tutorial_1207_p
@tutorial_1213_p
#This database supports user-defined variables. Variables start with @ and can be used wherever expressions or parameters are used. Variables not persisted and session scoped, that means only visible for the session where they are defined. A value is usually assigned using the SET command:
@tutorial_1208_p
@tutorial_1214_p
#It is also possible to change a value using the SET() method. This is useful in queries:
@tutorial_1209_p
@tutorial_1215_p
#Variables that are not set evaluate to NULL. The data type of a user-defined variable is the data type of the value assigned to it, that means it is not necessary (or possible) to declare variable names before using them. There are no restrictions on the assigned values; large objects (LOBs) are supported as well.
@tutorial_1210_h2
@tutorial_1216_h2
#Date and Time
@tutorial_1211_p
@tutorial_1217_p
#Date, time and timestamp values support ISO 8601 formatting, including time zone:
@tutorial_1212_p
@tutorial_1218_p
#If the time zone is not set, the value is parsed using the current time zone setting of the system. Date and time information is stored in H2 database files in GMT (Greenwich Mean Time). If the database is opened using another system time zone, the date and time will change accordingly. If you want to move a database from one time zone to the other and don't want this to happen, you need to create a SQL script file using the SCRIPT command or Script tool, and then load the database using the RUNSCRIPT command or the RunScript tool in the new time zone.
@tutorial_1213_h2
@tutorial_1219_h2
#Using Spring
@tutorial_1214_p
@tutorial_1220_p
#Use the following configuration to start and stop the H2 TCP Server using the Spring Framework:
@tutorial_1215_p
@tutorial_1221_p
#The "destroy-method" will help prevent exceptions on hot-redeployment or when restarting server.
