When using large transactions or a small log size, the database could get very slow (profiling shows the hotspot is in FileObjectDisk.sync()).
@changelog_1003_h2
Version 1.2.131 (2010-03-05)
@changelog_1003_li
The Shell tool now prints the stack trace when the list mode is enabled.
@changelog_1004_li
Older versions of H2 (version 1.2.127 and older) could not connect to a new version (version 1.2.129 and newer). The connection blocked when trying to connect. Now the connection no longer blocks, instead a SQL exception is thrown.
CREATE ALIAS ... AS: Compilation was incorrect if the source code contained characters that are not supported by the default file encoding.
@changelog_1005_li
In versions 1.2.129 and 1.2.130, a database could not be opened sometimes after dropping tables or indexes, and then creating new indexes for existing tables. The exception contained the text "parent not found" (version 1.2.129) or "Table not found" (version 1.2.130).
Issue 176: the JdbcDataSource now also supports a 'description' property.
@changelog_1006_li
After the database was closed, a null pointer exception could occur in Database.flush.
The Shell tool threw a IndexOutOfBoundsException after 20 statements.
@changelog_1007_li
When using the small version of H2 ('jarClient'), the first call to Connection.createBlob (or similar) could throw a ClassNotFoundException because the file org.h2.store.fs.FileSystemZip is not included. This missing class is now ignored.
@changelog_1008_li
Literals of type BIGINT now have the correct data type.
@changelog_1009_h2
Version 1.2.131 (2010-03-05)
@changelog_1010_li
Older versions of H2 (version 1.2.127 and older) could not connect to a new version (version 1.2.129 and newer). The connection blocked when trying to connect. Now the connection no longer blocks, instead a SQL exception is thrown.
@changelog_1011_li
In versions 1.2.129 and 1.2.130, a database could not be opened sometimes after dropping tables or indexes, and then creating new indexes for existing tables. The exception contained the text "parent not found" (version 1.2.129) or "Table not found" (version 1.2.130).
@changelog_1012_li
After the database was closed, a null pointer exception could occur in Database.flush.
@changelog_1013_li
An IndexOutOfBoundsException could occur in the page store (eg. on "delete from table"). Fixed.
@changelog_1008_h2
@changelog_1014_h2
Version 1.2.130 (2010-02-26)
@changelog_1009_li
@changelog_1015_li
EXPLAIN: The query plan now contains ".tableScan" if a table scan is used.
@changelog_1010_li
@changelog_1016_li
IN(..): when combining and IN(..) condition with a condition that didn't use an index, the result could contain duplicate rows.
@changelog_1011_li
@changelog_1017_li
IN(..): the index was not used if there were multiple IN(..) conditions.
@changelog_1012_li
@changelog_1018_li
For foreign key constraints, the metadata column INFORMATION_SCHEMA.INDEXES.CONSTRAINT_NAME was not set for non-unique indexes.
@changelog_1013_li
@changelog_1019_li
PostgreSQL compatibility: when using the following exception was thrown: Column "T.TYPTYPMOD" not found. Fixed. This is only when using psqlodbc_08_04*.
@changelog_1014_li
@changelog_1020_li
A tool to migrate an old database from the non-page store format to the newest version has been added in src/tools/org/h2/dev/util/Migrate.java. This file is not included in the jar file currently.
@changelog_1015_li
@changelog_1021_li
When using temporary tables, the database didn't shrink sometimes when closing. Also, sometimes a database could not recover normally.
@changelog_1016_li
@changelog_1022_li
Large transactions could run out of heap space. The maximum size of a transaction is now much larger.
@changelog_1017_li
@changelog_1023_li
The default setting for the system property h2.webMaxValueLength is now 100000 (it was 10000 before).
@changelog_1018_li
@changelog_1024_li
Creating a database was delayed about 2 seconds if the directory didn't exist.
@changelog_1019_li
@changelog_1025_li
Implemented INIT feature. If the database URL contains ";INIT=...;" then the DDL or DML commands following are executed on startup. Example URL: jdbc:h2:mem:test;INIT=RUNSCRIPT FROM '~/create.sql' (patch from Kerry Sainsbury).
@changelog_1020_h2
@changelog_1026_h2
Version 1.2.129 (2010-02-19)
@changelog_1021_li
@changelog_1027_li
The methods of the CloseListener are added to the Trigger interface. The interface CloseListener is removed. This is potentially a breaking change for existing triggers.
@changelog_1022_li
@changelog_1028_li
CREATE ALIAS: error message when compiling Java code have been improved.
@changelog_1023_li
@changelog_1029_li
MVCC: creating a table with an incorrect constraint could cause strange errors.
@changelog_1024_li
@changelog_1030_li
Hash indexes now are only used for single column indexes.
@changelog_1025_li
@changelog_1031_li
The cache types WEAK_* and TQ are no longer supported. A weak reference cache never frees up memory so it's the same as having a very large cache size. The TQ cache was not included in the jar file since a longer time, and was not tested.
@changelog_1026_li
@changelog_1032_li
The file system abstraction no longer throws SQL exceptions.
@changelog_1027_li
@changelog_1033_li
DatabaseEventListener.diskSpaceIsLow has changed.
@changelog_1028_li
@changelog_1034_li
The CompressTool no longer throw as SQL exceptions. Instead, it throws runtime exceptions.
@changelog_1029_li
@changelog_1035_li
SimpleResultSet.addColumn and addRow now can throw a IllegalStateException instead of a SQLException.
@changelog_1030_li
@changelog_1036_li
When doing an index lookup, decimal values with the same value but different scale (for example 0.00 and 0.0) where not considered equal in version 1.2.128. Now they are (unlike BigDecimal.equals()).
@changelog_1031_li
@changelog_1037_li
The BNF parser now uses the visitor pattern.
@changelog_1032_li
@changelog_1038_li
Converting a UUID to bytes was incorrect. Because of that, updatable result sets on tables with UUID primary key did not work.
@changelog_1033_li
@changelog_1039_li
The database URL property DATABASE_EVENT_LISTENER_OBJECT is no longer supported (there are problems passing objects when the PostgreSQL driver is installed as well).
@changelog_1034_li
@changelog_1040_li
H2 Console: asynchronous login (using a DatabaseEventListener) is no longer supported.
@changelog_1035_li
@changelog_1041_li
A workaround for a Windows socket problem has been implemented. Thanks a lot to Sergi Vladykin.
@changelog_1036_li
@changelog_1042_li
The Recover tool did not convert correctly convert CLOB data with non-ASCII characters.
@changelog_1037_li
@changelog_1043_li
Tools: the method run(String... args) has been renamed to runTool(String... args).
@changelog_1038_li
@changelog_1044_li
Server.startWebServer(Connection) was not working as expected.
@changelog_1039_li
@changelog_1045_li
The database URL option ACCESS_MODE_LOG is no longer supported.
@changelog_1040_li
@changelog_1046_li
The database URL option RECOVER has currently no effect.
@changelog_1041_li
@changelog_1047_li
Converting an old (non-page store) database is no longer supported using this version.
@changelog_1042_li
@changelog_1048_li
The following system properties are no longer supported: h2.overflowExceptions, h2.optimizeDropDependencies, h2.optimizeGroupSorted, h2.optimizeMinMax, h2.optimizeNot, h2.optimizeIn, h2.optimizeInJoin, h2.reuseSpace*. Most of then were there for a long time, but always with the same value. There was no unit test with the other value. So changing them was potentially dangerous (not a lot, but still).
@changelog_1043_li
@changelog_1049_li
The setting LOG has currently no effect (it only had an effect when the page store was disabled).
@changelog_1044_li
@changelog_1050_li
Disabling the page store is no longer supported. The old storage mechanism has been removed, shrinking the jar file size by almost 10%.
@changelog_1045_li
@changelog_1051_li
The translated resources are now stored in UTF-8 format.
@changelog_1046_li
@changelog_1052_li
The Windows service wrapper now detects if multiple versions of H2 are installed.
@changelog_1047_h2
@changelog_1053_h2
Version 1.2.128 (2010-01-30)
@changelog_1048_li
@changelog_1054_li
There are known errors on rollback when the page store is disabled and at the same time MVCC is used. See http://code.google.com/p/h2database/issues/detail?id=158
@changelog_1049_li
@changelog_1055_li
The DeleteDbFiles tool deleted all files in the .lob.db directory, even files that didn't belong to the database.
@changelog_1050_li
@changelog_1056_li
Automatic conversion of old databases to the page store format failed if the database contained LOB files.
@changelog_1051_li
@changelog_1057_li
Nested subqueries didn't work for INSERT INTO and IN(..). Example: insert into test ((select 1));
@changelog_1052_li
@changelog_1058_li
If the database was already closed using SHUTDOWN IMMEDIATELY, closing a second connection could throw a NullPointerException if there was a local temporary table.
@changelog_1053_li
@changelog_1059_li
Less classes are loaded when using the database in embedded mode.
@changelog_1054_li
@changelog_1060_li
The information schema tables are only initialized when needed. This reduces memory usage and speeds up creating in-memory databases. Each in-memory database needs about 8 KB of heap memory.
@changelog_1055_li
@changelog_1061_li
Nested UNION/INTERSECT queries with brackets could produce the wrong result if used within a subquery. Example: select count(*) from (select 1 union (select 2 intersect select 2)) x;
@changelog_1056_li
@changelog_1062_li
Comparing an column against a constant expression with a higher precision or length than the column could give wrong results (the expression was truncated before comparing).
@changelog_1057_li
@changelog_1063_li
Improved PostgreSQL compatibility (support SHOW DEFAULT_TRANSACTION_ISOLATION).
@changelog_1058_li
@changelog_1064_li
Documentation: the javadocs for Csv.write and read used the wrong default charset.
@changelog_1059_li
@changelog_1065_li
MVCC: if the table was locked in exclusive mode (such as SELECT ... FOR UPDATE), another session could query the table. This is now longer possible.
@changelog_1060_li
@changelog_1066_li
If a FOR UPDATE query was executed twice (using a PreparedStatement), the table was not locked.
@changelog_1061_li
@changelog_1067_li
Triggers: INSTEAD OF triggers are now supported. Such triggers can be defined on views.
@changelog_1062_li
@changelog_1068_li
New system property h2.identifiersToUpper. If set to false, identifiers in SQL statements are case sensitive even if they are not quoted.
@changelog_1063_li
@changelog_1069_li
Slightly improved performance if the table is already locked.
@changelog_1064_li
@changelog_1070_li
CompressLZF: faster decompression.
@changelog_1065_li
@changelog_1071_li
PgServer: the wrong size was sent for VARCHAR data. Thanks again to Sergi Vladykin for the patch.
@changelog_1066_li
@changelog_1072_li
Serialized access mode (server-less multi-connection mode): fixed getGeneratedKeys() for sequences.
@changelog_1067_h2
@changelog_1073_h2
Version 1.2.127 (2010-01-15)
@changelog_1068_li
@changelog_1074_li
Serialized access mode (server-less multi-connection mode): sequences did not work as expected (there were gaps in generated values when using multiple connections).
@changelog_1069_li
@changelog_1075_li
Page store: new databases can not be opened with older versions.
@changelog_1070_li
@changelog_1076_li
Page store: adding data to new database is now faster.
@changelog_1071_li
@changelog_1077_li
File system: getting the file name from a path is now faster. This should speed up BLOB and CLOB access.
@changelog_1072_li
@changelog_1078_li
PgServer: incorrect SQL types were returned in result set meta data. Concurrently opening a database could fail (PG catalog initialization was not synchronized). Thanks a lot to Sergi Vladykin for providing the patches!
@changelog_1073_li
@changelog_1079_li
SHOW COLUMNS did not work correctly if there where multiple indexes on the same columns.
@changelog_1074_li
@changelog_1080_li
Page store: the wrong write count was written to the database header. This could cause the server-less multi-connection mode to fail.
@changelog_1075_li
@changelog_1081_li
Result sets larger than 2 GB threw an exception "Negative seek offset". Fixed.
@changelog_1076_li
@changelog_1082_li
If the system property h2.check was set to false, an ArrayIndexOutOfBoundsException could occur.
@changelog_1077_li
@changelog_1083_li
Alter table is now supported even if a table has views defined.
@changelog_1078_li
@changelog_1084_li
Fulltext search: exceptions within the fulltext search package had the wrong SQL state.
@changelog_1079_li
@changelog_1085_li
The Lucene fulltext search ignored transaction rollback. Fixed using a trigger on rollback.
@changelog_1080_li
@changelog_1086_li
Trigger can now be called on rollback.
@changelog_1081_li
@changelog_1087_li
The shell script h2.sh ignored command line line arguments.
@changelog_1082_li
@changelog_1088_li
When running H2 in the Google AppEngine for Java, a AccessControlException could be thrown when trying to open a read-only database. Fixed.
@changelog_1083_li
@changelog_1089_li
The user home directory prefix (~) is now only expanded when followed by a slash or backslash, or standing alone.
@changelog_1084_li
@changelog_1090_li
Native fulltext search: before inserting or deleting data, FT_INIT() had to be called. This is no longer required.
@changelog_1085_li
@changelog_1091_li
The .trace.db file is now only created if required.
@changelog_1086_li
@changelog_1092_li
Shell tool: improved PostgreSQL compatibility.
@changelog_1087_li
@changelog_1093_li
Trying to open a database in read-only mode when a .lock.db file exists will now fail with a nice error message.
@changelog_1088_li
@changelog_1094_li
H2 Console: data that is too long is now abbreviated as follows: text... (100000 characters). A large binary is abbreviated as follows: abcdef... (100000 bytes).
@changelog_1089_li
@changelog_1095_li
Faster data conversion from BIGINT or INT to DECIMAL.
@changelog_1090_li
@changelog_1096_li
Server-less multi-connection mode: try to delete log files if switching between read/write operations.
@changelog_1091_li
@changelog_1097_li
CompressLZF: Faster decompress and improved javadocs
@changelog_1092_h2
@changelog_1098_h2
Version 1.2.126 (2009-12-18)
@changelog_1093_li
@changelog_1099_li
The ChangeFileEncryption tool will now fail with an exception if the database is still in use. The Backup tool will also fail except when running in quiet mode.
@changelog_1094_li
@changelog_1100_li
CSVREAD: when reading the column names from the CSV file, column names that contain no special characters are considered case insensitive now.
@changelog_1095_li
@changelog_1101_li
Optimization index conditions of the form 'column=NULL' (which is always false; unlike 'column IS NULL').
@changelog_1096_li
@changelog_1102_li
Script command and tool: the primary key constraint is now listed before inserting the data. This will result in a smaller database when using the page store.
@changelog_1097_li
@changelog_1103_li
Statements with IN(SELECT..) conditions could produce the wrong result. Example: index on id, name; query: select * from test where id between 1 and 3 and name in (select 'World').
@changelog_1098_li
@changelog_1104_li
Statements with IN(..) conditions could produce the wrong result when using views or nested select statements. Example: index on id; index on name; query: select * from (select * from test) where id=1 and name in('a', 'b'). select * from (select * from test) where id=1 and name in('Hello', 'World').
@changelog_1099_li
@changelog_1105_li
Page store: a rollback of a relatively large transaction could fail with an ArrayIndexOutOfBoundsException or a 'row not found' exception in the PageBtreeIndex in some cases.
@changelog_1100_li
@changelog_1106_li
JaQu: the decompiler has been improved, and a few test cases already work. It is still incomplete however.
@changelog_1101_li
@changelog_1107_li
LIKE: any letter is now allowed after the escape character (which is still '\' by default). Previously, an exception was thrown (unlike other databases) if it was not the escape character, '_' or '%'. If the escape character appears at the end of the pattern, the result is it is ignored (like PostgreSQL and MS SQL Server).
@changelog_1102_li
@changelog_1108_li
The reserve heap memory is no longer used.
@changelog_1103_li
@changelog_1109_li
Database.checkpoint() could throw a NullPointerException.
@changelog_1104_h2
@changelog_1110_h2
Version 1.2.125 (2009-12-06)
@changelog_1105_li
@changelog_1111_li
Lucene fulltext search: the Lucene field names now match the table column names, except if the column names start with _ (in which case another _ is prepended). Unfortunately this change means existing fulltext indexes need to be re-built.
@changelog_1106_li
@changelog_1112_li
The shell tool now has a very simple statement history.
@changelog_1107_li
@changelog_1113_li
The zip file system implementation now supports the '~' home directory prefix. Example database URL: jdbc:h2:zip:~/test.zip!/test
@changelog_1108_li
@changelog_1114_li
Right outer joins on tables that were already 'inner joined' was processed incorrectly.
@changelog_1109_li
@changelog_1115_li
Temporary files from LOB objects were not deleted early enough when using the server mode.
@changelog_1110_li
@changelog_1116_li
Trying to alter a temporary table threw a strange exception. It is still not possible to do that, but the exception message is better now.
@changelog_1111_li
@changelog_1117_li
When the system property h2.maxMemoryRowsDistinct was set, and using SELECT DISTINCT, the temporary table was not correctly dropped. This could cause problems in recovery when the process was killed.
@changelog_1112_li
@changelog_1118_li
Trigger that are called before a select statement are now supported. This allows to create tables that work like materialized views.
@changelog_1113_li
@changelog_1119_li
Non-row based triggers were called even if the action didn't match the declared action (INSERT triggers were also called when deleting rows). This has been changed. The MERGE statement calls both INSERT and DELETE triggers.
@changelog_1114_li
@changelog_1120_li
Statements with IN(..) conditions could produce the wrong result or a data conversion error (since version 1.2.120). Examples: index on id, name, condition: id=1 and name in('Hello', 'x'); index on id, query: select * from (select * from test) where id=1 and name in('Hello', 'World').
@changelog_1115_li
@changelog_1121_li
The CompressTool was not multithreading safe. Because of this, the following database operations where also not multithreading safe (even when using different databases): the SCRIPT command (only when using compression), the COMPRESS function, and storing CLOB or BLOB data (only when compression is enabled).
@changelog_1116_li
@changelog_1122_li
The compression algorithm "LZF" is now about 33% faster than before when compressing small block (around 2 KB). It is much faster than Deflate, but the compression ratio is lower. Some of the optimizations are from Sam Van Oort, thanks a lot!
@changelog_1117_li
@changelog_1123_li
Compressing large blocks of data didn't work when using the "Deflate" compression algorithm. Compressing a lot of data could run out of heap memory.
@changelog_1118_li
@changelog_1124_li
The test cases don't access the file system directly, this simplifies GAE for Java testing. Thanks to Vince Bonfanti.
@changelog_1119_li
@changelog_1125_li
More bugs in the server-less multi-connection mode have been fixed.
@changelog_1120_li
@changelog_1126_li
When running against an old database, the SCRIPT statement could generate a SQL script that contained duplicate indexes (PRIMARY_KEY_E).
@changelog_1121_li
@changelog_1127_li
JdbcConnectionPool.getConnection() could throw a NullPointerException.
@changelog_1122_li
@changelog_1128_li
User defined functions: the source code is now available using SELECT SOURCE FROM INFORMATION_SCHEMA.FUNCTION_ALIASES.
@changelog_1123_li
@changelog_1129_li
User defined functions with source code didn't work after re-opening the database.
@changelog_1124_li
@changelog_1130_li
The newsfeeds are now Atom 1.0 standard compliant.
@changelog_1125_li
@changelog_1131_li
The database is now closed after an out of memory exception, because the database could get corrupt otherwise.
@changelog_1126_li
@changelog_1132_li
Better error message if both AUTO_SERVER and SERIALIZED parameters are set to TRUE.
@changelog_1127_li
@changelog_1133_li
Drop table did not delete lob files in old file store (not PAGE_STORE).
@changelog_1128_h2
@changelog_1134_h2
Version 1.2.124 (2009-11-20)
@changelog_1129_li
@changelog_1135_li
Clustering: there is now a way to detect which cluster instances are running.
@changelog_1130_li
@changelog_1136_li
ConvertTraceFile: the SQL statement statistics are better formatted (newline are removed).
@changelog_1131_li
@changelog_1137_li
The file lock thread is now stopped when the database is closed.
@changelog_1132_li
@changelog_1138_li
Issue 140: the Script tool now supports writing to a stream.
@changelog_1133_li
@changelog_1139_li
Issue 138: the trace output of Statement.execute(String, int) and executeUpdate was incorrect.
@changelog_1134_li
@changelog_1140_li
Page store: new databases can not be opened with older versions.
@changelog_1135_li
@changelog_1141_li
Page store: multi-column indexes didn't work if the cache was very small.
@changelog_1136_li
@changelog_1142_li
Page store: opening a database could theoretically result in an endless loop.
@changelog_1137_li
@changelog_1143_li
Page store: adding large indexed columns could get very slow.
@changelog_1138_li
@changelog_1144_li
Page store: after a duplicate key exception, an ArrayIndexOutOfBoundsException could be thrown (only for very large rows).
@changelog_1139_li
@changelog_1145_li
Page store: the recover tool sometimes generated a script file that contained duplicate data.
@changelog_1140_li
@changelog_1146_li
Page store: sometimes opening a read-only database failed.
@changelog_1141_li
@changelog_1147_li
Page store: opening a database sometimes failed if large rows where updated, or if a table was truncated before.
@changelog_1142_li
@changelog_1148_li
Page store: when using a very small page size (128 bytes or smaller), writing a large row could result in an endless recursion. This is only a theoretical problem, as the page size is 2 KB.
@changelog_1143_li
@changelog_1149_li
Page store: getting the min value from a descending index with NULL entries could return the wrong result.
@changelog_1144_li
@changelog_1150_li
Page store: improved auto-recovery after power failure.
@changelog_1145_li
@changelog_1151_li
The JDBC client did not detect that it was not talking to an H2 server. This could result in strange exceptions when trying to connect to another kind of server.
@changelog_1146_li
@changelog_1152_li
User defined functions can be created with source code. Example: CREATE ALIAS HI AS 'String hi() { return "Hello"; }'
@changelog_1147_li
@changelog_1153_li
Database file lock: the exception "lock file modified in the future" is no longer thrown; instead, opening the file will be delayed by 2 seconds.
@changelog_1148_li
@changelog_1154_li
Inserting LOBs got slower each time the process was restarted. It could loop endlessly after about 1000 process restarts.
@changelog_1149_li
@changelog_1155_li
Issue 117: Multi-version concurrency: concurrent MERGE statements now work.
@changelog_1150_li
@changelog_1156_li
Improved read-only database detection.
@changelog_1151_h2
@changelog_1157_h2
Version 1.2.123 (2009-11-08)
@changelog_1152_li
@changelog_1158_li
Page store: new databases can not be opened with older versions.
@changelog_1153_li
@changelog_1159_li
Page store: updating large rows (rows with more than 2000 bytes of data) could corrupt the database.
@changelog_1154_li
@changelog_1160_li
Page store: inserting very large rows failed with ArrayIndexOutOfBoundsException.
@changelog_1155_li
@changelog_1161_li
When using multi-threaded kernel mode, setting disabling locking (LOCK_MODE=0) will now throw an exception. At this time this combination will result in corruption when multiple threads try to update the same table.
@changelog_1156_li
@changelog_1162_li
The fulltext search methods and fields are now protected instead of private, to make the classes more easily extensible.
@changelog_1157_li
@changelog_1163_li
The Lucene fulltext search now also returns the score.
@changelog_1158_li
@changelog_1164_li
New function SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger.
@changelog_1159_li
@changelog_1165_li
Statement.getGeneratedKeys() returned the wrong value if a trigger changed the identity value after inserting the row.
@changelog_1160_li
@changelog_1166_li
Improved error messages: identifiers and values are now quoted.
@changelog_1161_li
@changelog_1167_li
Improved error message when casting a value failed: the column name and type is included in the message.
@changelog_1162_li
@changelog_1168_li
Improved support for GAE for Java thanks to Vince Bonfanti.
@changelog_1163_h2
@changelog_1169_h2
Version 1.2.122 (2009-10-28)
@changelog_1164_li
@changelog_1170_li
The native fulltext search now supports streaming CLOB data.
@changelog_1165_li
@changelog_1171_li
If the database URL ends with ;PAGE_STORE=TRUE and a database in the old format exists, it is automatically converted to the new page store format if possible. A backup of the database is created first. Automatic conversion is not supported if the database was not closed normally (if it contains uncommitted transactions).
@changelog_1166_li
@changelog_1172_li
Dropping the current user is now allowed if another admin user exists.
@changelog_1167_li
@changelog_1173_li
Values of type BINARY or BLOB could not be converted to the data type OTHER.
@changelog_1168_li
@changelog_1174_li
SHUTDOWN COMPACT now fully compacts the database.
@changelog_1169_li
@changelog_1175_li
New system properties h2.maxCompactCount and h2.maxCompactTime to allow changing the default behavior (at most 2 seconds compacting when closing the database).
@changelog_1170_li
@changelog_1176_li
New sorted insert optimization (see Performance / Database Performance Tuning).
@changelog_1171_li
@changelog_1177_li
Issue 116: The files h2*-sources.jar and h2*-javadoc.jar are now in the Maven repository.
@changelog_1172_li
@changelog_1178_li
Page store: opening a large database was slow if it was not closed before.
@changelog_1173_li
@changelog_1179_li
Page store: new write and read counters in the meta data table. Use SELECT * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME IN( 'info.FILE_WRITE_TOTAL', 'info.FILE_WRITE', 'info.FILE_READ', 'info.CACHE_MAX_SIZE', 'info.CACHE_SIZE')
@changelog_1174_li
@changelog_1180_li
The SQL syntax is documented using (railroad) diagrams. The diagrams are HTML.
@changelog_1175_li
@changelog_1181_li
The documentation is no longer available in Japanese because the translation was too much out of sync. Please use the Google translation instead.
@changelog_1176_li
@changelog_1182_li
Certain queries were not sorted if subselect queries were involved
@changelog_1177_li
@changelog_1183_li
More bugs in the server-less multi-connection mode have been fixed: 90097 The database is read only, caches must be cleared on reconnect, etc.
@changelog_1178_h2
@changelog_1184_h2
Version 1.2.121 (2009-10-11)
@changelog_1179_li
@changelog_1185_li
Better support GaeVFS (Google App Engine Virtual File System) thanks to Thanks to Vince Bonfanti.
@changelog_1180_li
@changelog_1186_li
CSVREAD didn't close the file. Thanks to Vince Bonfanti for the patch!
@changelog_1181_li
@changelog_1187_li
If a database in the old format exists, it is now used. The system property is used for new databases, or if databases exist in both formats. In any case, the flag in the URL overrides this logic.
@changelog_1182_li
@changelog_1188_li
Page store bugs were fixed. Large values in indexed columns could corrupt the index.
@changelog_1183_li
@changelog_1189_li
The page store did not work when using Retrotranslator (because the Retrotranslator doesn't support Integer.reverse and Long.reverse).
@changelog_1184_li
@changelog_1190_li
New system property h2.pageStoreTrim to disable shrinking the database when closing (disabled by default, meaning by default the database is trimmed).
@changelog_1185_h2
@changelog_1191_h2
Version 1.2.120 (2009-10-04)
@changelog_1186_li
@changelog_1192_li
This is a beta version.
@changelog_1187_li
@changelog_1193_li
Large updates could throw an ArrayIndexOutOfBoundsException in RowList.writeRow.
@changelog_1188_li
@changelog_1194_li
In version 1.2, the following system properties are now enabled by default: h2.pageStore, h2.nullConcatIsNull, h2.optimizeInList. The default value for h2.defaultMaxLengthInplaceLob is now 4096 (it was 1024 with version 1.1).
@changelog_1189_li
@changelog_1195_li
New databases are now stored in the new 'page store' file format. Existing databases are kept in the old file format. To use the old file format, append ;PAGE_STORE=FALSE to the database URL or set the system property h2.pageStore to false.
@changelog_1190_li
@changelog_1196_li
Issue 125: Renaming primary keys was not persistent. Fixed. Unfortunately, databases created by this version can not be opened with older versions because of this change.
@changelog_1191_li
@changelog_1197_li
Issue 124: Hibernate schema validation failed for decimal/numeric columns. This problem is fixed in the Hibernate dialect that is included with H2 (src/tools/org/hibernate/dialect/H2Dialect.java.txt), but not in Hibernate yet.
@changelog_1192_li
@changelog_1198_li
PostgreSQL compatibility: function LASTVAL() as an alias for IDENTITY().
@changelog_1193_li
@changelog_1199_li
Linked tables now support default values when inserting, updating or merging.
@changelog_1194_li
@changelog_1200_li
Bugfixes in the page store.
@changelog_1195_li
@changelog_1201_li
Possibility to set a vendor id in Constants.java, so that unofficial builds are distinguishable from official releases.
@changelog_1196_li
@changelog_1202_li
Allow writing to linked tables in readonly databases.
@changelog_1197_h2
@changelog_1203_h2
Version 1.1.119 (2009-09-26)
@changelog_1198_li
@changelog_1204_li
SQL statements in the exception message are no longer included if they contain '--hide--'.
@changelog_1199_li
@changelog_1205_li
Temporary local tables did not always work after reconnect if AUTO_SERVER=TRUE
@changelog_1200_li
@changelog_1206_li
New system property h2.defaultMaxLengthInplaceLob to change the default maximum size of an in-place LOB object.
@changelog_1201_li
@changelog_1207_li
New system property h2.nullConcatIsNull to change the default null concatenation behavior. The default will be enabled in version 1.2.
@changelog_1202_li
@changelog_1208_li
The cache algorithm TQ is disabled in this version, because it is unstable, and because the current implementation does not have any measurable advantages over the default.
@changelog_1203_li
@changelog_1209_li
New committer: Christian Peter. He works for <a href="http://www.docware.com">Docware</a> and helped a lot finding and fixing bugs, and generally improving the database. He is now a committer.
@changelog_1204_li
@changelog_1210_li
ChangeFileEncryption did not work with Lob subdirectories. Fixed.
@changelog_1205_li
@changelog_1211_li
Issue 121: JaQu: new simple update and merge methods.
@changelog_1206_li
@changelog_1212_li
Issue 120: JaQu didn't close result sets.
@changelog_1207_li
@changelog_1213_li
Issue 119: JaQu creates wrong WHERE conditions on some inputs.
@changelog_1208_li
@changelog_1214_li
The new page store mechanism is now alpha-level quality. The next release will most likely be "1.2.120 beta" where this mode is enabled by default. To use it right now, append ;PAGE_STORE=TRUE to the database URL. The file format of this mode will probably not change any more.
@changelog_1209_li
@changelog_1215_li
SELECT COUNT(*) FROM SYSTEM_RANGE(...) returned the wrong result. Fixed.
@changelog_1210_li
@changelog_1216_li
The Recover tool now also processes the log files, however applying those changes is still a manual process.
@changelog_1211_li
@changelog_1217_li
New sample application that shows how to pass data to a trigger.
@changelog_1212_li
@changelog_1218_li
More bugs in the server-less multi-connection mode have been fixed: On Windows, two processes could write to the same database at the same time.
@changelog_1213_li
@changelog_1219_li
When loading triggers or other client classes (static functions, database event listener, user aggregate functions, other JDBC drivers), the database now uses the context class loader if the class could not be found using Class.forName().
@changelog_1214_li
@changelog_1220_li
Updating many rows with the same CLOB or BLOB values could result in FileNotFoundException.
@changelog_1215_li
@changelog_1221_li
Statement.getConnection() threw an exception if the connection was already closed.
@changelog_1216_li
@changelog_1222_li
The native fulltext index kept a reference to a database after the database was closed.
@changelog_1217_li
@changelog_1223_li
Non-unique in-memory hash indexes are now supported. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1218_li
@changelog_1224_li
The optimizer does a better job for joins if indexes are missing.
@changelog_1219_h2
@changelog_1225_h2
Version 1.1.118 (2009-09-04)
@changelog_1220_li
@changelog_1226_li
SHOW COLUMNS only listed indexed columns.
@changelog_1221_li
@changelog_1227_li
When calling SHUTDOWN IMMEDIATELY in the server mode, the .trace.db file was not closed.
@changelog_1222_li
@changelog_1228_li
DatabaseMetaData.getPrimaryKeys: the wrong constraint name was reported if there was another constraint on the same table and columns.
@changelog_1223_li
@changelog_1229_li
AUTO_INCREMENT now works in the same way in ALTER TABLE ALTER COLUMN as in CREATE TABLE (it does not create a primary key).
@changelog_1224_li
@changelog_1230_li
Native fulltext search: before searching, FT_INIT() had to be called. This is no longer required.
@changelog_1225_li
@changelog_1231_li
Better support GaeVFS (Google App Engine Virtual File System).
@changelog_1226_li
@changelog_1232_li
JaQu: the plan is to support natural (pure Java / Scala) conditions such as (id == 1 && name.equals("Test")). A proof of concept decompiler is now included (it doesn't work yet).
@changelog_1227_li
@changelog_1233_li
Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1228_li
@changelog_1234_li
PreparedStatement.setObject now converts a java.lang.Character to a string.
@changelog_1229_li
@changelog_1235_li
H2 Console: PierPaolo Ucchino has completed the Italian translation. Thanks a lot!
@changelog_1230_li
@changelog_1236_li
Various tools now use Java 5 var-args, such as main the methods and SimpleResultSet.addRow.
@changelog_1231_li
@changelog_1237_li
H2 Console: indexes of tables of non-default schemas are now also listed.
@changelog_1232_li
@changelog_1238_li
Issue 111: Multi-version concurrency / duplicate primary key after rollback.
@changelog_1233_li
@changelog_1239_li
Issue 110: Multi-version concurrency / wrong exception is thrown.
@changelog_1234_li
@changelog_1240_li
Parser: sequenceName.NEXTVAL and CURRVAL did not respect the schema search path.
@changelog_1235_li
@changelog_1241_li
Issue 101: The following sequence could throw the exception "Row not found when trying to delete": start a transaction, insert many rows, delete many rows, rollback. The number of rows depends on the cache size.
@changelog_1236_li
@changelog_1242_li
The stack trace of very common exceptions is no longer written to the .trace.db file by default.
@changelog_1237_li
@changelog_1243_li
An optimization for OR is implemented, but disabled by default. Expressions of the type X=1 OR X=2 are converted to X IN(1, 2). To enable, set the system property h2.optimizeInList to true before loading the H2 JDBC driver.
@changelog_1238_li
@changelog_1244_li
An optimization for IN(..) and IN(SELECT...) is implemented, but disabled by default. To enable, set the system property h2.optimizeInList to true before loading the H2 JDBC driver. If enabled, this overrides h2.optimizeIn and h2.optimizeInJoin. Unlike now, this optimization will also speed up updates and deletes.
@changelog_1239_h2
@changelog_1245_h2
Version 1.1.117 (2009-08-09)
@changelog_1240_li
@changelog_1246_li
New committer: Sam Van Oort has been contributing to H2 since quite some time in many ways (on the mailing list, documentation, and in the form of patches). He is now a committer.
@changelog_1241_li
@changelog_1247_li
JaQu: the order of the fields in the database no longer needs to match the order in the database.
@changelog_1242_li
@changelog_1248_li
Issue 103: MVCC: the setting MAX_MEMORY_UNDO can currently not be supported when using multi-version concurrency, that means the complete undo log must fit in memory.
@changelog_1243_li
@changelog_1249_li
LIKE: the escape mechanism can now be disable using ESCAPE ''. The default escape character can be changed using the system property h2.defaultEscape. The default is still '\' (as in MySQL and PostgreSQL).
@changelog_1244_li
@changelog_1250_li
Views using functions were not re-evaluated when necessary.
@changelog_1245_li
@changelog_1251_li
Improved MySQL compatibility for SHOW COLUMNS.
@changelog_1246_li
@changelog_1252_li
Improved PostgreSQL compatibility for timestamp literals with timezone.
@changelog_1247_li
@changelog_1253_li
Sergi Vladykin translated the error messages to Russian. Thanks a lot!
@changelog_1248_li
@changelog_1254_li
Support for Java 6 DatabaseMetaData.getTables, getColumns, getProcedures, and getProcedureColumns.
@changelog_1249_li
@changelog_1255_li
Issue 101: Rollback of a large transaction (more than 100000 rows) could fail.
@changelog_1250_li
@changelog_1256_li
Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1251_li
@changelog_1257_li
The functions LENGTH, OCTET_LENGTH, and BIT_LENGTH now return BIGINT.
@changelog_1252_li
@changelog_1258_li
Data types CLOB and BLOB: the maximum precision was Integer.MAX_VALUE, it is now Long.MAX_VALUE.
@changelog_1253_li
@changelog_1259_li
Multi-threaded kernel: creating and dropping temporary database objects and the potentially free pages list was not correctly synchronized. Thanks a lot to Eric Faulhaber for the test case and patch!
@changelog_1254_li
@changelog_1260_li
Parsing SQL script files is now faster.
@changelog_1255_li
@changelog_1261_li
CSV reading is now faster.
@changelog_1256_li
@changelog_1262_li
SimpleResultSet.newInstance(SimpleRowSource rs) did not work.
@changelog_1257_h2
@changelog_1263_h2
Version 1.1.116 (2009-07-18)
@changelog_1258_li
@changelog_1264_li
Server-less multi-connection mode: more bugs are fixed.
@changelog_1259_li
@changelog_1265_li
The built-in help (INFORMATION_SCHEMA.HELP) is smaller, shrinking the jar file size a bit.
@changelog_1260_li
@changelog_1266_li
H2 Console: column of tables of non-default schemas are now also listed, except for schemas starting with 'INFO'.
@changelog_1261_li
@changelog_1267_li
ALTER TABLE: removing an auto-increment or identity column didn't remove the sequence.
@changelog_1262_li
@changelog_1268_li
Creating indexes is now a bit faster.
@changelog_1263_li
@changelog_1269_li
PG Server: new system property h2.pgClientEncoding to explicitly set the encoding for clients that don't send the encoding (the default encoding is UTF-8). Thanks a lot to Sergi Vladykin for the patch!
@changelog_1264_li
@changelog_1270_li
PG Server: improved compatibility by using the type ids of the PostgreSQL driver. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1265_li
@changelog_1271_li
H2 Console: Oracle system tables are no longer listed, improving performance.
@changelog_1266_li
@changelog_1272_li
Result sets are now read-only except if the statement or prepared statement was created with the concurrency ResultSet.CONCUR_UPDATABLE. This change is required because the old behavior (all result set are updatable) violated the JDBC spec. For backward compatibility, use the system property h2.defaultResultSetConcurrency.
@changelog_1267_li
@changelog_1273_li
New system property h2.defaultResultSetConcurrency to change the default result set concurrency.
@changelog_1268_li
@changelog_1274_li
JDBC: using an invalid result set type or concurrency now throws an exception.
@changelog_1269_li
@changelog_1275_li
If a pooled connection was not closed but garbage collected, a NullPointerException could occur.
@changelog_1270_li
@changelog_1276_li
Fulltext search: a NullPointerException was thrown when updating a value that was NULL previously.
@changelog_1271_li
@changelog_1277_li
The Recover tool did not work with .data.db files of the wrong size.
@changelog_1272_li
@changelog_1278_li
Triggers: if there was an exception when initializing a trigger, this exception could be hidden, and in some cases (specially when using the Lucene fulltext index mechanism) a NullPointerException was thrown later on. Now the exception that occurred on init is thrown when changing data.
@changelog_1273_li
@changelog_1279_li
The soft-references cache (CACHE_TYPE=SOFT_LRU) could throw a NullPointerException.
@changelog_1274_li
@changelog_1280_li
To enable the new page store mechanism, append ;PAGE_STORE=TRUE to the database URL. or set the system property h2.pageStore to true. This mechanism is still experimental, and the file format will change, but it is quite stable now.
@changelog_1275_h2
@changelog_1281_h2
Version 1.1.115 (2009-06-21)
@changelog_1276_li
@changelog_1282_li
The new storage mechanism is now alpha quality. To try it out, set the system property "h2.pageStore" to "true" (java -Dh2.pageStore=true). There are still bugs to be found and fixed, for example inserting many rows references a lot of main memory. Performance is currently about the same as with the regular storage mechanism, but the database file size is smaller. The file format is not stable yet.
@changelog_1277_li
@changelog_1283_li
ALTER TABLE could throw an exception "object already exists" in some cases.
@changelog_1278_li
@changelog_1284_li
Views: in some situations, an ArrayIndexOutOfBoundsException was thrown when using the same view concurrently.
@changelog_1279_li
@changelog_1285_li
java.util.UUID is now supported in PreparedStatement.setObject and user defined Java functions. ResultSet.getObject() returns a java.util.UUID when using the UUID data type.
@changelog_1280_li
@changelog_1286_li
H2 Console: the language was reset to the browser language when disconnecting.
@changelog_1281_li
@changelog_1287_li
H2 Console: improved Polish translation.
@changelog_1282_li
@changelog_1288_li
Server-less multi-connection mode: more bugs are fixed.
@changelog_1283_li
@changelog_1289_li
The download page now included the SHA1 checksums.
@changelog_1284_li
@changelog_1290_li
Shell tool: the file encoding workaround is now documented if you run java org.h2.tools.Shell -?.
@changelog_1285_li
@changelog_1291_li
The RunScript tool and SQL statement did not work with the compression method LZF.
@changelog_1286_li
@changelog_1292_li
Fulltext search: searching for NULL or an empty string threw an exception.
@changelog_1287_li
@changelog_1293_li
Lucene fulltext search: FTL_DROP_ALL did not drop the triggers.
@changelog_1288_li
@changelog_1294_li
Backup: if the database contained CLOB or BLOB data, the backup included a file entry for the LOB directory. This caused the restore to fail.
@changelog_1289_li
@changelog_1295_li
Data types: LONG is now an alias for BIGINT.
@changelog_1290_h2
@changelog_1296_h2
Version 1.1.114 (2009-06-01)
@changelog_1291_li
@changelog_1297_li
ResultSetMetaData.getColumnClassName returned the wrong class for CLOB and BLOB columns.
@changelog_1292_li
@changelog_1298_li
Fulltext search: data is no longer deleted and re-inserted if the indexed columns didn't change.
@changelog_1293_li
@changelog_1299_li
In some situations, an ArrayIndexOutOfBoundsException was thrown when adding rows. This was caused by a bug in the b-tree code.
@changelog_1294_li
@changelog_1300_li
Microsoft Windows Vista: when using the the installer, Vista wrote "This program may not have installed correctly." This message should no longer appear (in the h2.nsi file, the line 'RequestExecutionLevel highest' was added).
@changelog_1295_li
@changelog_1301_li
The Recover tool did not always work when the database contains referential integrity constraints.
@changelog_1296_li
@changelog_1302_li
Java 1.5 is now required to run H2. If required, Retrotranslator can be used to create a Java 1.4 version (http://retrotranslator.sourceforge.net/).
@changelog_1297_h2
@changelog_1303_h2
Version 1.1.113 (2009-05-21)
@changelog_1298_li
@changelog_1304_li
Shell tool: the built-in commands EXIT, HELP, ?, LIST, and so on didn't work with a semicolon at the end.
@changelog_1299_li
@changelog_1305_li
JDK 1.5 is now required to build the jar file. However it is still possible to create a jar file for Java 1.4. For details, see buildRelease.sh and buildRelease.bat. As an alternative, compile using JDK 1.5 or 1.6 and use Retrotranslator to create a Java 1.4 version (http://retrotranslator.sourceforge.net/).
@changelog_1300_li
@changelog_1306_li
When deleting or updating many rows in a table, the space in the index file was not re-used in the default mode (persistent database, b-tree index, LOG=1). This caused the index file to grow over time. Workarounds were to delete and re-created the index file, alter the table (add a remove a column), or append ;LOG=2 to the database URL. To disable the change, set the system property h2.reuseSpaceBtreeIndex to false.
@changelog_1301_li
@changelog_1307_li
Identifiers with a digit and then a dollar sign didn't work. Example: A1$B.
@changelog_1302_li
@changelog_1308_li
MS SQL Server compatibility: support for linked tables with NVARCHAR, NCHAR, NCLOB, and LONGNVARCHAR.
@changelog_1303_li
@changelog_1309_li
Android: workaround for a problem when using read-only databases in zip files (skip seems to be implemented incorrectly on the Android system).
@changelog_1304_li
@changelog_1310_li
Calling execute() or prepareStatement() with null as the SQL statement now throws an exception.
@changelog_1305_li
@changelog_1311_li
Benchmark: the number of executed statements was incorrect. The H2 database was loaded at the beginning of the test to collect results, now it is loaded at the very end. Thanks to Fred Toussi from HSQLDB for reporting those problems. However the changed do not affect the relative performance.
@changelog_1306_li
@changelog_1312_li
H2 Console: command line settings are no longer stored in the properties file. They are now only used for the current process, except if they are explicitly saved.
@changelog_1307_li
@changelog_1313_li
Cache: support for a second level soft-references cache. To enable it, append ;CACHE_TYPE=SOFT_LRU (or SOFT_TQ) to the database URL, or set the system property h2.cacheTypeDefault to "SOFT_LRU" / "SOFT_TQ". Enabling the second level cache reduces performance for small databases, but speeds up large databases. It makes sense to use it if the available memory size is unknown. Thanks a lot to Jan Kotek!
@changelog_1308_h2
@changelog_1314_h2
Version 1.1.112 (2009-05-01)
@changelog_1309_li
@changelog_1315_li
JdbcPreparedStatement.toString() could throw a NullPointerException.
@changelog_1310_li
@changelog_1316_li
EclipseLink: added H2Platform.supportsIdentity().
@changelog_1311_li
@changelog_1317_li
Connection pool: the default login timeout is now 5 minutes.
@changelog_1312_li
@changelog_1318_li
After truncating tables, opening large databases could become slow because indexes were always re-built unnecessarily when opening.
@changelog_1313_li
@changelog_1319_li
More bugs in the server-less multi-connection mode have been fixed: Sometimes parameters of prepared statements were lost when a reconnecting. Concurrent read operations were slow. To improve performance, executeQuery(..) must be used for queries (execute(..) switches to the write mode, which is slow).
@changelog_1314_li
@changelog_1320_li
GROUP BY queries with a self-join (join to the same table) that were grouped by columns with indexes returned the wrong result in some cases.
@changelog_1315_li
@changelog_1321_li
Improved error message when the .lock.db file modification time is in the future.
@changelog_1316_li
@changelog_1322_li
The MERGE statement now returns 0 as the generated key if the row was updated.
@changelog_1317_li
@changelog_1323_li
Running code coverage is now automated.
@changelog_1318_li
@changelog_1324_li
A file system implementation can now be registered using FileSystem.register.
@changelog_1319_li
@changelog_1325_li
The database file system is no longer included in the jar file, it moved to the test section.
@changelog_1320_h2
@changelog_1326_h2
Version 1.1.111 (2009-04-10)
@changelog_1321_li
@changelog_1327_li
In-memory databases can now run inside the Google App Engine.
@changelog_1322_li
@changelog_1328_li
Queries that are ordered by an indexed column returned no rows in certain cases (if all rows were deleted from the table previously, and there is a low number of rows in the table, and when not using other conditions, and when using the default b tree index).
@changelog_1323_li
@changelog_1329_li
The wrong exception was thrown when using unquoted text for the SQL statements COMMENT, ALTER USER, and SET PASSWORD.
@changelog_1324_li
@changelog_1330_li
The built-in connection pool did not roll back transactions and enable autocommit enabled after closing a connection.
@changelog_1325_li
@changelog_1331_li
Sometimes a StackOverflow occurred when checking for deadlock. See also http://code.google.com/p/h2database/issues/detail?id=61
@changelog_1326_li
@changelog_1332_li
The Shell tool no longer truncates results with only one column, and displays a message if data was truncated.
@cheatSheet_1000_h1
...
...
@@ -8135,43 +8153,43 @@ Option to shutdown all the running servers (on the same VM).
Full outer joins.
@roadmap_1014_li
Support mixed clustering mode (one embedded, others in server mode).
Automatic collection of statistics (auto ANALYZE; AUTOVACUUM). See http://www.postgresql.org/docs/current/static/routine-vacuuming.html#AUTOVACUUM
@roadmap_1015_li
PostgreSQL catalog: use BEFORE SELECT triggers instead of views over metadata tables.
Support mixed clustering mode (one embedded, others in server mode).
@roadmap_1016_li
Test very large databases and LOBs (up to 256 GB).
PostgreSQL catalog: use BEFORE SELECT triggers instead of views over metadata tables.
@roadmap_1017_li
Support hints for the optimizer (which index to use, enforce the join order).
Test very large databases and LOBs (up to 256 GB).
@roadmap_1018_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).
Support hints for the optimizer (which index to use, enforce the join order).
@roadmap_1019_li
Clustering: recovery needs to becomes fully automatic. Global write lock feature.
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).
@roadmap_1020_li
Clustering: reads should be randomly distributed (optional) or to a designated database on RAM (parameter: READ_FROM=3).
Clustering: recovery needs to becomes fully automatic. Global write lock feature.
@roadmap_1021_li
Sequence: add features [NO] MINVALUE, MAXVALUE, CYCLE.
Clustering: reads should be randomly distributed (optional) or to a designated database on RAM (parameter: READ_FROM=3).
Migrate database tool (also from other database engines).
Add a migration guide (list differences between databases).
@roadmap_1026_li
Automatic collection of statistics (auto ANALYZE; AUTOVACUUM). See http://www.postgresql.org/docs/current/static/routine-vacuuming.html#AUTOVACUUM
Migrate database tool (also from other database engines).
@roadmap_1027_li
Optimization: automatic index creation suggestion using the trace file?
...
...
@@ -8405,7 +8423,7 @@ Support custom Collators.
Document ROWNUM usage for reports: SELECT ROWNUM, * FROM (subquery).
@roadmap_1104_li
MS SQL Server compatibility: support 1+'2'=3, '1'+'2'='12'
MS SQL Server compatibility: support string concatenation using +: 1+'2'=3, '1'+'2'='12'
@roadmap_1105_li
Clustering: when a database is back alive, automatically synchronize with the master.
...
...
@@ -9893,278 +9911,281 @@ Restore from a Script
Online Backup
@tutorial_1137_p
The <code>BACKUP</code> SQL statement and the <code>Backup</code> tool both create a zip file with all database files. However, the contents of this file are not human readable. Other than the SCRIPT statement, the <code>BACKUP</code> statement does not lock the database objects, and therefore does not block other users. The resulting backup is transactionally consistent:
The <code>BACKUP</code> SQL statement and the <code>Backup</code> tool both create a zip file with all database files. However, the contents of this file are not human readable.
@tutorial_1138_p
The <code>Backup</code> tool (<code>org.h2.tools.Backup</code>) can not be used to create a online backup; the database must not be in use while running this program.
Unlike than the SCRIPT statement, the <code>BACKUP</code> statement does not lock the database objects when using the multi-threaded mode, and therefore does not block other users. The resulting backup is transactionally consistent:
@tutorial_1139_p
Creating a backup while the database is running is not supported, except if the file systems support creating snapshots. The problem is that it can't be guaranteed that the data is copied in the right order.
The <code>Backup</code> tool (<code>org.h2.tools.Backup</code>) can not be used to create a online backup; the database must not be in use while running this program.
@tutorial_1140_p
Creating a backup by copying the database files while the database is running is not supported, except if the file systems support creating snapshots. The problem is that it can't be guaranteed that the data is copied in the right order.
@tutorial_1140_h2
@tutorial_1141_h2
Command Line Tools
@tutorial_1141_p
@tutorial_1142_p
This database comes with a number of command line tools. To get more information about a tool, start it with the parameter '-?', for example:
@tutorial_1142_p
@tutorial_1143_p
The command line tools are:
@tutorial_1143_code
@tutorial_1144_code
Backup
@tutorial_1144_li
@tutorial_1145_li
creates a backup of a database.
@tutorial_1145_code
@tutorial_1146_code
ChangeFileEncryption
@tutorial_1146_li
@tutorial_1147_li
allows changing the file encryption password or algorithm of a database.
@tutorial_1147_code
@tutorial_1148_code
Console
@tutorial_1148_li
@tutorial_1149_li
starts the browser based H2 Console.
@tutorial_1149_code
@tutorial_1150_code
ConvertTraceFile
@tutorial_1150_li
@tutorial_1151_li
converts a .trace.db file to a Java application and SQL script.
@tutorial_1151_code
@tutorial_1152_code
CreateCluster
@tutorial_1152_li
@tutorial_1153_li
creates a cluster from a standalone database.
@tutorial_1153_code
@tutorial_1154_code
DeleteDbFiles
@tutorial_1154_li
@tutorial_1155_li
deletes all files belonging to a database.
@tutorial_1155_code
@tutorial_1156_code
Recover
@tutorial_1156_li
@tutorial_1157_li
helps recovering a corrupted database.
@tutorial_1157_code
@tutorial_1158_code
Restore
@tutorial_1158_li
@tutorial_1159_li
restores a backup of a database.
@tutorial_1159_code
@tutorial_1160_code
RunScript
@tutorial_1160_li
@tutorial_1161_li
runs a SQL script against a database.
@tutorial_1161_code
@tutorial_1162_code
Script
@tutorial_1162_li
@tutorial_1163_li
allows converting a database to a SQL script for backup or migration.
@tutorial_1163_code
@tutorial_1164_code
Server
@tutorial_1164_li
@tutorial_1165_li
is used in the server mode to start a H2 server.
@tutorial_1165_code
@tutorial_1166_code
Shell
@tutorial_1166_li
@tutorial_1167_li
is a command line database tool.
@tutorial_1167_p
@tutorial_1168_p
The tools can also be called from an application by calling the main or another public method. For details, see the Javadoc documentation.
@tutorial_1168_h2
@tutorial_1169_h2
The Shell Tool
@tutorial_1169_p
@tutorial_1170_p
The Shell tool is a simple interactive command line tool. To start it, type:
@tutorial_1170_p
@tutorial_1171_p
You will be asked for a database URL, JDBC driver, user name, and password. The connection setting can also be set as command line parameters. After connecting, you will get the list of options. The built-in commands don't need to end with a semicolon, but SQL statements are only executed if the line ends with a semicolon <code>;</code>. This allows to enter multi-line statements:
@tutorial_1171_p
@tutorial_1172_p
By default, results are printed as a table. For results with many column, consider using the list mode:
@tutorial_1172_h2
@tutorial_1173_h2
Using OpenOffice Base
@tutorial_1173_p
@tutorial_1174_p
OpenOffice.org Base supports database access over the JDBC API. To connect to a H2 database using OpenOffice Base, you first need to add the JDBC driver to OpenOffice. The steps to connect to a H2 database are:
@tutorial_1174_li
@tutorial_1175_li
Start OpenOffice Writer, go to [Tools], [Options]
@tutorial_1175_li
@tutorial_1176_li
Make sure you have selected a Java runtime environment in OpenOffice.org / Java
@tutorial_1176_li
@tutorial_1177_li
Click [Class Path...], [Add Archive...]
@tutorial_1177_li
@tutorial_1178_li
Select your h2 jar file (location is up to you, could be wherever you choose)
@tutorial_1178_li
@tutorial_1179_li
Click [OK] (as much as needed), stop OpenOffice (including the Quickstarter)
@tutorial_1179_li
@tutorial_1180_li
Start OpenOffice Base
@tutorial_1180_li
@tutorial_1181_li
Connect to an existing database; select [JDBC]; [Next]
@tutorial_1181_li
@tutorial_1182_li
Example datasource URL: <code>jdbc:h2:~/test</code>
@tutorial_1182_li
@tutorial_1183_li
JDBC driver class: <code>org.h2.Driver</code>
@tutorial_1183_p
@tutorial_1184_p
Now you can access the database stored in the current users home directory.
@tutorial_1184_p
@tutorial_1185_p
To use H2 in NeoOffice (OpenOffice without X11):
@tutorial_1185_li
@tutorial_1186_li
In NeoOffice, go to [NeoOffice], [Preferences]
@tutorial_1186_li
@tutorial_1187_li
Look for the page under [NeoOffice], [Java]
@tutorial_1187_li
@tutorial_1188_li
Click [Class Path], [Add Archive...]
@tutorial_1188_li
@tutorial_1189_li
Select your h2 jar file (location is up to you, could be wherever you choose)
@tutorial_1189_li
@tutorial_1190_li
Click [OK] (as much as needed), restart NeoOffice.
@tutorial_1190_p
@tutorial_1191_p
Now, when creating a new database using the "Database Wizard" :
@tutorial_1191_li
@tutorial_1192_li
Click [File], [New], [Database].
@tutorial_1192_li
@tutorial_1193_li
Select [Connect to existing database] and the select [JDBC]. Click next.
@tutorial_1193_li
@tutorial_1194_li
Example datasource URL: <code>jdbc:h2:~/test</code>
@tutorial_1194_li
@tutorial_1195_li
JDBC driver class: <code>org.h2.Driver</code>
@tutorial_1195_p
@tutorial_1196_p
Another solution to use H2 in NeoOffice is:
@tutorial_1196_li
@tutorial_1197_li
Package the h2 jar within an extension package
@tutorial_1197_li
@tutorial_1198_li
Install it as a Java extension in NeoOffice
@tutorial_1198_p
@tutorial_1199_p
This can be done by create it using the NetBeans OpenOffice plugin. See also <a href="http://wiki.services.openoffice.org/wiki/Extensions_development_java">Extensions Development</a>.
@tutorial_1199_h2
@tutorial_1200_h2
Java Web Start / JNLP
@tutorial_1200_p
@tutorial_1201_p
When using Java Web Start / JNLP (Java Network Launch Protocol), permissions tags must be set in the .jnlp file, and the application .jar file must be signed. Otherwise, when trying to write to the file system, the following exception will occur: <code>java.security.AccessControlException</code>: access denied (<code>java.io.FilePermission ... read</code>). Example permission tags:
@tutorial_1201_h2
@tutorial_1202_h2
Using a Connection Pool
@tutorial_1202_p
@tutorial_1203_p
For H2, opening a connection is fast if the database is already open. Still, using a connection pool improves performance if you open and close connections a lot. A simple connection pool is included in H2. It is based on the <a href="http://www.source-code.biz/snippets/java/8.htm">Mini Connection Pool Manager</a> from Christian d'Heureuse. There are other, more complex, open source connection pools available, for example the <a href="http://jakarta.apache.org/commons/dbcp/">Apache Commons DBCP</a>. For H2, it is about twice as faster to get a connection from the built-in connection pool than to get one using <code>DriverManager.getConnection()</code>.The build-in connection pool is used as follows:
@tutorial_1203_h2
@tutorial_1204_h2
Fulltext Search
@tutorial_1204_p
@tutorial_1205_p
H2 includes two fulltext search implementations. One is using Apache Lucene, and the other (the native implementation) stores the index data in special tables in the database.
@tutorial_1205_h3
@tutorial_1206_h3
Using the Native Fulltext Search
@tutorial_1206_p
@tutorial_1207_p
To initialize, call:
@tutorial_1207_p
@tutorial_1208_p
You need to initialize it in each database where you want to use it. Afterwards, you can create a fulltext index for a table using:
@tutorial_1208_p
@tutorial_1209_p
PUBLIC is the schema name, 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 realtime. To search the index, use the following query:
@tutorial_1209_p
@tutorial_1210_p
This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1210_p
@tutorial_1211_p
To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in: <code>SELECT T.* FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID=FT.KEYS[0];</code>
@tutorial_1211_p
@tutorial_1212_p
You can also call the index from within a Java application:
@tutorial_1212_h3
@tutorial_1213_h3
Using the Lucene Fulltext Search
@tutorial_1213_p
@tutorial_1214_p
To use the Lucene full text search, you need the Lucene library in the classpath. How to do that depends on the application; if you use the H2 Console, you can add the Lucene jar file to the environment variables <code>H2DRIVERS</code> or <code>CLASSPATH</code>. To initialize the Lucene fulltext search in a database, call:
@tutorial_1214_p
@tutorial_1215_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_1215_p
@tutorial_1216_p
PUBLIC is the schema name, 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 realtime. To search the index, use the following query:
@tutorial_1216_p
@tutorial_1217_p
This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1217_p
@tutorial_1218_p
To get the raw data, use <code>FTL_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in: <code>SELECT T.* FROM FTL_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID=FT.KEYS[0];</code>
@tutorial_1218_p
@tutorial_1219_p
You can also call the index from within a Java application:
@tutorial_1219_h2
@tutorial_1220_h2
User-Defined Variables
@tutorial_1220_p
@tutorial_1221_p
This database supports user-defined variables. Variables start with <code>@</code> and can be used wherever expressions or parameters are allowed. Variables are not persisted and session scoped, that means only visible from within the session in which they are defined. A value is usually assigned using the SET command:
@tutorial_1221_p
@tutorial_1222_p
The value can also be changed using the SET() method. This is useful in queries:
@tutorial_1222_p
@tutorial_1223_p
Variables that are not set evaluate to <code>NULL</code>. The data type of a user-defined variable is the data type of the value assigned to it, that means it is not necessary (or possible) to declare variable names before using them. There are no restrictions on the assigned values; large objects (LOBs) are supported as well.
@tutorial_1223_h2
@tutorial_1224_h2
Date and Time
@tutorial_1224_p
@tutorial_1225_p
Date, time and timestamp values support ISO 8601 formatting, including time zone:
@tutorial_1225_p
@tutorial_1226_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 <code>SCRIPT</code> command or <code>Script</code> tool, and then load the database using the <code>RUNSCRIPT</code> command or the <code>RunScript</code> tool in the new time zone.
@tutorial_1226_h2
@tutorial_1227_h2
Using Spring
@tutorial_1227_p
@tutorial_1228_p
Use the following configuration to start and stop the H2 TCP server using the Spring Framework:
@tutorial_1228_p
@tutorial_1229_p
The <code>destroy-method</code> will help prevent exceptions on hot-redeployment or when restarting the server.
#When using large transactions or a small log size, the database could get very slow (profiling shows the hotspot is in FileObjectDisk.sync()).
@changelog_1003_h2
#Version 1.2.131 (2010-03-05)
@changelog_1003_li
#The Shell tool now prints the stack trace when the list mode is enabled.
@changelog_1004_li
#Older versions of H2 (version 1.2.127 and older) could not connect to a new version (version 1.2.129 and newer). The connection blocked when trying to connect. Now the connection no longer blocks, instead a SQL exception is thrown.
#CREATE ALIAS ... AS: Compilation was incorrect if the source code contained characters that are not supported by the default file encoding.
@changelog_1005_li
#In versions 1.2.129 and 1.2.130, a database could not be opened sometimes after dropping tables or indexes, and then creating new indexes for existing tables. The exception contained the text "parent not found" (version 1.2.129) or "Table not found" (version 1.2.130).
#Issue 176: the JdbcDataSource now also supports a 'description' property.
@changelog_1006_li
#After the database was closed, a null pointer exception could occur in Database.flush.
#The Shell tool threw a IndexOutOfBoundsException after 20 statements.
@changelog_1007_li
#When using the small version of H2 ('jarClient'), the first call to Connection.createBlob (or similar) could throw a ClassNotFoundException because the file org.h2.store.fs.FileSystemZip is not included. This missing class is now ignored.
@changelog_1008_li
#Literals of type BIGINT now have the correct data type.
@changelog_1009_h2
#Version 1.2.131 (2010-03-05)
@changelog_1010_li
#Older versions of H2 (version 1.2.127 and older) could not connect to a new version (version 1.2.129 and newer). The connection blocked when trying to connect. Now the connection no longer blocks, instead a SQL exception is thrown.
@changelog_1011_li
#In versions 1.2.129 and 1.2.130, a database could not be opened sometimes after dropping tables or indexes, and then creating new indexes for existing tables. The exception contained the text "parent not found" (version 1.2.129) or "Table not found" (version 1.2.130).
@changelog_1012_li
#After the database was closed, a null pointer exception could occur in Database.flush.
@changelog_1013_li
#An IndexOutOfBoundsException could occur in the page store (eg. on "delete from table"). Fixed.
@changelog_1008_h2
@changelog_1014_h2
#Version 1.2.130 (2010-02-26)
@changelog_1009_li
@changelog_1015_li
#EXPLAIN: The query plan now contains ".tableScan" if a table scan is used.
@changelog_1010_li
@changelog_1016_li
#IN(..): when combining and IN(..) condition with a condition that didn't use an index, the result could contain duplicate rows.
@changelog_1011_li
@changelog_1017_li
#IN(..): the index was not used if there were multiple IN(..) conditions.
@changelog_1012_li
@changelog_1018_li
#For foreign key constraints, the metadata column INFORMATION_SCHEMA.INDEXES.CONSTRAINT_NAME was not set for non-unique indexes.
@changelog_1013_li
@changelog_1019_li
#PostgreSQL compatibility: when using the following exception was thrown: Column "T.TYPTYPMOD" not found. Fixed. This is only when using psqlodbc_08_04*.
@changelog_1014_li
@changelog_1020_li
#A tool to migrate an old database from the non-page store format to the newest version has been added in src/tools/org/h2/dev/util/Migrate.java. This file is not included in the jar file currently.
@changelog_1015_li
@changelog_1021_li
#When using temporary tables, the database didn't shrink sometimes when closing. Also, sometimes a database could not recover normally.
@changelog_1016_li
@changelog_1022_li
#Large transactions could run out of heap space. The maximum size of a transaction is now much larger.
@changelog_1017_li
@changelog_1023_li
#The default setting for the system property h2.webMaxValueLength is now 100000 (it was 10000 before).
@changelog_1018_li
@changelog_1024_li
#Creating a database was delayed about 2 seconds if the directory didn't exist.
@changelog_1019_li
@changelog_1025_li
#Implemented INIT feature. If the database URL contains ";INIT=...;" then the DDL or DML commands following are executed on startup. Example URL: jdbc:h2:mem:test;INIT=RUNSCRIPT FROM '~/create.sql' (patch from Kerry Sainsbury).
@changelog_1020_h2
@changelog_1026_h2
#Version 1.2.129 (2010-02-19)
@changelog_1021_li
@changelog_1027_li
#The methods of the CloseListener are added to the Trigger interface. The interface CloseListener is removed. This is potentially a breaking change for existing triggers.
@changelog_1022_li
@changelog_1028_li
#CREATE ALIAS: error message when compiling Java code have been improved.
@changelog_1023_li
@changelog_1029_li
#MVCC: creating a table with an incorrect constraint could cause strange errors.
@changelog_1024_li
@changelog_1030_li
#Hash indexes now are only used for single column indexes.
@changelog_1025_li
@changelog_1031_li
#The cache types WEAK_* and TQ are no longer supported. A weak reference cache never frees up memory so it's the same as having a very large cache size. The TQ cache was not included in the jar file since a longer time, and was not tested.
@changelog_1026_li
@changelog_1032_li
#The file system abstraction no longer throws SQL exceptions.
@changelog_1027_li
@changelog_1033_li
#DatabaseEventListener.diskSpaceIsLow has changed.
@changelog_1028_li
@changelog_1034_li
#The CompressTool no longer throw as SQL exceptions. Instead, it throws runtime exceptions.
@changelog_1029_li
@changelog_1035_li
#SimpleResultSet.addColumn and addRow now can throw a IllegalStateException instead of a SQLException.
@changelog_1030_li
@changelog_1036_li
#When doing an index lookup, decimal values with the same value but different scale (for example 0.00 and 0.0) where not considered equal in version 1.2.128. Now they are (unlike BigDecimal.equals()).
@changelog_1031_li
@changelog_1037_li
#The BNF parser now uses the visitor pattern.
@changelog_1032_li
@changelog_1038_li
#Converting a UUID to bytes was incorrect. Because of that, updatable result sets on tables with UUID primary key did not work.
@changelog_1033_li
@changelog_1039_li
#The database URL property DATABASE_EVENT_LISTENER_OBJECT is no longer supported (there are problems passing objects when the PostgreSQL driver is installed as well).
@changelog_1034_li
@changelog_1040_li
#H2 Console: asynchronous login (using a DatabaseEventListener) is no longer supported.
@changelog_1035_li
@changelog_1041_li
#A workaround for a Windows socket problem has been implemented. Thanks a lot to Sergi Vladykin.
@changelog_1036_li
@changelog_1042_li
#The Recover tool did not convert correctly convert CLOB data with non-ASCII characters.
@changelog_1037_li
@changelog_1043_li
#Tools: the method run(String... args) has been renamed to runTool(String... args).
@changelog_1038_li
@changelog_1044_li
#Server.startWebServer(Connection) was not working as expected.
@changelog_1039_li
@changelog_1045_li
#The database URL option ACCESS_MODE_LOG is no longer supported.
@changelog_1040_li
@changelog_1046_li
#The database URL option RECOVER has currently no effect.
@changelog_1041_li
@changelog_1047_li
#Converting an old (non-page store) database is no longer supported using this version.
@changelog_1042_li
@changelog_1048_li
#The following system properties are no longer supported: h2.overflowExceptions, h2.optimizeDropDependencies, h2.optimizeGroupSorted, h2.optimizeMinMax, h2.optimizeNot, h2.optimizeIn, h2.optimizeInJoin, h2.reuseSpace*. Most of then were there for a long time, but always with the same value. There was no unit test with the other value. So changing them was potentially dangerous (not a lot, but still).
@changelog_1043_li
@changelog_1049_li
#The setting LOG has currently no effect (it only had an effect when the page store was disabled).
@changelog_1044_li
@changelog_1050_li
#Disabling the page store is no longer supported. The old storage mechanism has been removed, shrinking the jar file size by almost 10%.
@changelog_1045_li
@changelog_1051_li
#The translated resources are now stored in UTF-8 format.
@changelog_1046_li
@changelog_1052_li
#The Windows service wrapper now detects if multiple versions of H2 are installed.
@changelog_1047_h2
@changelog_1053_h2
#Version 1.2.128 (2010-01-30)
@changelog_1048_li
@changelog_1054_li
#There are known errors on rollback when the page store is disabled and at the same time MVCC is used. See http://code.google.com/p/h2database/issues/detail?id=158
@changelog_1049_li
@changelog_1055_li
#The DeleteDbFiles tool deleted all files in the .lob.db directory, even files that didn't belong to the database.
@changelog_1050_li
@changelog_1056_li
#Automatic conversion of old databases to the page store format failed if the database contained LOB files.
@changelog_1051_li
@changelog_1057_li
#Nested subqueries didn't work for INSERT INTO and IN(..). Example: insert into test ((select 1));
@changelog_1052_li
@changelog_1058_li
#If the database was already closed using SHUTDOWN IMMEDIATELY, closing a second connection could throw a NullPointerException if there was a local temporary table.
@changelog_1053_li
@changelog_1059_li
#Less classes are loaded when using the database in embedded mode.
@changelog_1054_li
@changelog_1060_li
#The information schema tables are only initialized when needed. This reduces memory usage and speeds up creating in-memory databases. Each in-memory database needs about 8 KB of heap memory.
@changelog_1055_li
@changelog_1061_li
#Nested UNION/INTERSECT queries with brackets could produce the wrong result if used within a subquery. Example: select count(*) from (select 1 union (select 2 intersect select 2)) x;
@changelog_1056_li
@changelog_1062_li
#Comparing an column against a constant expression with a higher precision or length than the column could give wrong results (the expression was truncated before comparing).
@changelog_1057_li
@changelog_1063_li
#Improved PostgreSQL compatibility (support SHOW DEFAULT_TRANSACTION_ISOLATION).
@changelog_1058_li
@changelog_1064_li
#Documentation: the javadocs for Csv.write and read used the wrong default charset.
@changelog_1059_li
@changelog_1065_li
#MVCC: if the table was locked in exclusive mode (such as SELECT ... FOR UPDATE), another session could query the table. This is now longer possible.
@changelog_1060_li
@changelog_1066_li
#If a FOR UPDATE query was executed twice (using a PreparedStatement), the table was not locked.
@changelog_1061_li
@changelog_1067_li
#Triggers: INSTEAD OF triggers are now supported. Such triggers can be defined on views.
@changelog_1062_li
@changelog_1068_li
#New system property h2.identifiersToUpper. If set to false, identifiers in SQL statements are case sensitive even if they are not quoted.
@changelog_1063_li
@changelog_1069_li
#Slightly improved performance if the table is already locked.
@changelog_1064_li
@changelog_1070_li
#CompressLZF: faster decompression.
@changelog_1065_li
@changelog_1071_li
#PgServer: the wrong size was sent for VARCHAR data. Thanks again to Sergi Vladykin for the patch.
@changelog_1066_li
@changelog_1072_li
#Serialized access mode (server-less multi-connection mode): fixed getGeneratedKeys() for sequences.
@changelog_1067_h2
@changelog_1073_h2
#Version 1.2.127 (2010-01-15)
@changelog_1068_li
@changelog_1074_li
#Serialized access mode (server-less multi-connection mode): sequences did not work as expected (there were gaps in generated values when using multiple connections).
@changelog_1069_li
@changelog_1075_li
#Page store: new databases can not be opened with older versions.
@changelog_1070_li
@changelog_1076_li
#Page store: adding data to new database is now faster.
@changelog_1071_li
@changelog_1077_li
#File system: getting the file name from a path is now faster. This should speed up BLOB and CLOB access.
@changelog_1072_li
@changelog_1078_li
#PgServer: incorrect SQL types were returned in result set meta data. Concurrently opening a database could fail (PG catalog initialization was not synchronized). Thanks a lot to Sergi Vladykin for providing the patches!
@changelog_1073_li
@changelog_1079_li
#SHOW COLUMNS did not work correctly if there where multiple indexes on the same columns.
@changelog_1074_li
@changelog_1080_li
#Page store: the wrong write count was written to the database header. This could cause the server-less multi-connection mode to fail.
@changelog_1075_li
@changelog_1081_li
#Result sets larger than 2 GB threw an exception "Negative seek offset". Fixed.
@changelog_1076_li
@changelog_1082_li
#If the system property h2.check was set to false, an ArrayIndexOutOfBoundsException could occur.
@changelog_1077_li
@changelog_1083_li
#Alter table is now supported even if a table has views defined.
@changelog_1078_li
@changelog_1084_li
#Fulltext search: exceptions within the fulltext search package had the wrong SQL state.
@changelog_1079_li
@changelog_1085_li
#The Lucene fulltext search ignored transaction rollback. Fixed using a trigger on rollback.
@changelog_1080_li
@changelog_1086_li
#Trigger can now be called on rollback.
@changelog_1081_li
@changelog_1087_li
#The shell script h2.sh ignored command line line arguments.
@changelog_1082_li
@changelog_1088_li
#When running H2 in the Google AppEngine for Java, a AccessControlException could be thrown when trying to open a read-only database. Fixed.
@changelog_1083_li
@changelog_1089_li
#The user home directory prefix (~) is now only expanded when followed by a slash or backslash, or standing alone.
@changelog_1084_li
@changelog_1090_li
#Native fulltext search: before inserting or deleting data, FT_INIT() had to be called. This is no longer required.
@changelog_1085_li
@changelog_1091_li
#The .trace.db file is now only created if required.
@changelog_1086_li
@changelog_1092_li
#Shell tool: improved PostgreSQL compatibility.
@changelog_1087_li
@changelog_1093_li
#Trying to open a database in read-only mode when a .lock.db file exists will now fail with a nice error message.
@changelog_1088_li
@changelog_1094_li
#H2 Console: data that is too long is now abbreviated as follows: text... (100000 characters). A large binary is abbreviated as follows: abcdef... (100000 bytes).
@changelog_1089_li
@changelog_1095_li
#Faster data conversion from BIGINT or INT to DECIMAL.
@changelog_1090_li
@changelog_1096_li
#Server-less multi-connection mode: try to delete log files if switching between read/write operations.
@changelog_1091_li
@changelog_1097_li
#CompressLZF: Faster decompress and improved javadocs
@changelog_1092_h2
@changelog_1098_h2
#Version 1.2.126 (2009-12-18)
@changelog_1093_li
@changelog_1099_li
#The ChangeFileEncryption tool will now fail with an exception if the database is still in use. The Backup tool will also fail except when running in quiet mode.
@changelog_1094_li
@changelog_1100_li
#CSVREAD: when reading the column names from the CSV file, column names that contain no special characters are considered case insensitive now.
@changelog_1095_li
@changelog_1101_li
#Optimization index conditions of the form 'column=NULL' (which is always false; unlike 'column IS NULL').
@changelog_1096_li
@changelog_1102_li
#Script command and tool: the primary key constraint is now listed before inserting the data. This will result in a smaller database when using the page store.
@changelog_1097_li
@changelog_1103_li
#Statements with IN(SELECT..) conditions could produce the wrong result. Example: index on id, name; query: select * from test where id between 1 and 3 and name in (select 'World').
@changelog_1098_li
@changelog_1104_li
#Statements with IN(..) conditions could produce the wrong result when using views or nested select statements. Example: index on id; index on name; query: select * from (select * from test) where id=1 and name in('a', 'b'). select * from (select * from test) where id=1 and name in('Hello', 'World').
@changelog_1099_li
@changelog_1105_li
#Page store: a rollback of a relatively large transaction could fail with an ArrayIndexOutOfBoundsException or a 'row not found' exception in the PageBtreeIndex in some cases.
@changelog_1100_li
@changelog_1106_li
#JaQu: the decompiler has been improved, and a few test cases already work. It is still incomplete however.
@changelog_1101_li
@changelog_1107_li
#LIKE: any letter is now allowed after the escape character (which is still '\' by default). Previously, an exception was thrown (unlike other databases) if it was not the escape character, '_' or '%'. If the escape character appears at the end of the pattern, the result is it is ignored (like PostgreSQL and MS SQL Server).
@changelog_1102_li
@changelog_1108_li
#The reserve heap memory is no longer used.
@changelog_1103_li
@changelog_1109_li
#Database.checkpoint() could throw a NullPointerException.
@changelog_1104_h2
@changelog_1110_h2
#Version 1.2.125 (2009-12-06)
@changelog_1105_li
@changelog_1111_li
#Lucene fulltext search: the Lucene field names now match the table column names, except if the column names start with _ (in which case another _ is prepended). Unfortunately this change means existing fulltext indexes need to be re-built.
@changelog_1106_li
@changelog_1112_li
#The shell tool now has a very simple statement history.
@changelog_1107_li
@changelog_1113_li
#The zip file system implementation now supports the '~' home directory prefix. Example database URL: jdbc:h2:zip:~/test.zip!/test
@changelog_1108_li
@changelog_1114_li
#Right outer joins on tables that were already 'inner joined' was processed incorrectly.
@changelog_1109_li
@changelog_1115_li
#Temporary files from LOB objects were not deleted early enough when using the server mode.
@changelog_1110_li
@changelog_1116_li
#Trying to alter a temporary table threw a strange exception. It is still not possible to do that, but the exception message is better now.
@changelog_1111_li
@changelog_1117_li
#When the system property h2.maxMemoryRowsDistinct was set, and using SELECT DISTINCT, the temporary table was not correctly dropped. This could cause problems in recovery when the process was killed.
@changelog_1112_li
@changelog_1118_li
#Trigger that are called before a select statement are now supported. This allows to create tables that work like materialized views.
@changelog_1113_li
@changelog_1119_li
#Non-row based triggers were called even if the action didn't match the declared action (INSERT triggers were also called when deleting rows). This has been changed. The MERGE statement calls both INSERT and DELETE triggers.
@changelog_1114_li
@changelog_1120_li
#Statements with IN(..) conditions could produce the wrong result or a data conversion error (since version 1.2.120). Examples: index on id, name, condition: id=1 and name in('Hello', 'x'); index on id, query: select * from (select * from test) where id=1 and name in('Hello', 'World').
@changelog_1115_li
@changelog_1121_li
#The CompressTool was not multithreading safe. Because of this, the following database operations where also not multithreading safe (even when using different databases): the SCRIPT command (only when using compression), the COMPRESS function, and storing CLOB or BLOB data (only when compression is enabled).
@changelog_1116_li
@changelog_1122_li
#The compression algorithm "LZF" is now about 33% faster than before when compressing small block (around 2 KB). It is much faster than Deflate, but the compression ratio is lower. Some of the optimizations are from Sam Van Oort, thanks a lot!
@changelog_1117_li
@changelog_1123_li
#Compressing large blocks of data didn't work when using the "Deflate" compression algorithm. Compressing a lot of data could run out of heap memory.
@changelog_1118_li
@changelog_1124_li
#The test cases don't access the file system directly, this simplifies GAE for Java testing. Thanks to Vince Bonfanti.
@changelog_1119_li
@changelog_1125_li
#More bugs in the server-less multi-connection mode have been fixed.
@changelog_1120_li
@changelog_1126_li
#When running against an old database, the SCRIPT statement could generate a SQL script that contained duplicate indexes (PRIMARY_KEY_E).
@changelog_1121_li
@changelog_1127_li
#JdbcConnectionPool.getConnection() could throw a NullPointerException.
@changelog_1122_li
@changelog_1128_li
#User defined functions: the source code is now available using SELECT SOURCE FROM INFORMATION_SCHEMA.FUNCTION_ALIASES.
@changelog_1123_li
@changelog_1129_li
#User defined functions with source code didn't work after re-opening the database.
@changelog_1124_li
@changelog_1130_li
#The newsfeeds are now Atom 1.0 standard compliant.
@changelog_1125_li
@changelog_1131_li
#The database is now closed after an out of memory exception, because the database could get corrupt otherwise.
@changelog_1126_li
@changelog_1132_li
#Better error message if both AUTO_SERVER and SERIALIZED parameters are set to TRUE.
@changelog_1127_li
@changelog_1133_li
#Drop table did not delete lob files in old file store (not PAGE_STORE).
@changelog_1128_h2
@changelog_1134_h2
#Version 1.2.124 (2009-11-20)
@changelog_1129_li
@changelog_1135_li
#Clustering: there is now a way to detect which cluster instances are running.
@changelog_1130_li
@changelog_1136_li
#ConvertTraceFile: the SQL statement statistics are better formatted (newline are removed).
@changelog_1131_li
@changelog_1137_li
#The file lock thread is now stopped when the database is closed.
@changelog_1132_li
@changelog_1138_li
#Issue 140: the Script tool now supports writing to a stream.
@changelog_1133_li
@changelog_1139_li
#Issue 138: the trace output of Statement.execute(String, int) and executeUpdate was incorrect.
@changelog_1134_li
@changelog_1140_li
#Page store: new databases can not be opened with older versions.
@changelog_1135_li
@changelog_1141_li
#Page store: multi-column indexes didn't work if the cache was very small.
@changelog_1136_li
@changelog_1142_li
#Page store: opening a database could theoretically result in an endless loop.
@changelog_1137_li
@changelog_1143_li
#Page store: adding large indexed columns could get very slow.
@changelog_1138_li
@changelog_1144_li
#Page store: after a duplicate key exception, an ArrayIndexOutOfBoundsException could be thrown (only for very large rows).
@changelog_1139_li
@changelog_1145_li
#Page store: the recover tool sometimes generated a script file that contained duplicate data.
@changelog_1140_li
@changelog_1146_li
#Page store: sometimes opening a read-only database failed.
@changelog_1141_li
@changelog_1147_li
#Page store: opening a database sometimes failed if large rows where updated, or if a table was truncated before.
@changelog_1142_li
@changelog_1148_li
#Page store: when using a very small page size (128 bytes or smaller), writing a large row could result in an endless recursion. This is only a theoretical problem, as the page size is 2 KB.
@changelog_1143_li
@changelog_1149_li
#Page store: getting the min value from a descending index with NULL entries could return the wrong result.
@changelog_1144_li
@changelog_1150_li
#Page store: improved auto-recovery after power failure.
@changelog_1145_li
@changelog_1151_li
#The JDBC client did not detect that it was not talking to an H2 server. This could result in strange exceptions when trying to connect to another kind of server.
@changelog_1146_li
@changelog_1152_li
#User defined functions can be created with source code. Example: CREATE ALIAS HI AS 'String hi() { return "Hello"; }'
@changelog_1147_li
@changelog_1153_li
#Database file lock: the exception "lock file modified in the future" is no longer thrown; instead, opening the file will be delayed by 2 seconds.
@changelog_1148_li
@changelog_1154_li
#Inserting LOBs got slower each time the process was restarted. It could loop endlessly after about 1000 process restarts.
@changelog_1149_li
@changelog_1155_li
#Issue 117: Multi-version concurrency: concurrent MERGE statements now work.
@changelog_1150_li
@changelog_1156_li
#Improved read-only database detection.
@changelog_1151_h2
@changelog_1157_h2
#Version 1.2.123 (2009-11-08)
@changelog_1152_li
@changelog_1158_li
#Page store: new databases can not be opened with older versions.
@changelog_1153_li
@changelog_1159_li
#Page store: updating large rows (rows with more than 2000 bytes of data) could corrupt the database.
@changelog_1154_li
@changelog_1160_li
#Page store: inserting very large rows failed with ArrayIndexOutOfBoundsException.
@changelog_1155_li
@changelog_1161_li
#When using multi-threaded kernel mode, setting disabling locking (LOCK_MODE=0) will now throw an exception. At this time this combination will result in corruption when multiple threads try to update the same table.
@changelog_1156_li
@changelog_1162_li
#The fulltext search methods and fields are now protected instead of private, to make the classes more easily extensible.
@changelog_1157_li
@changelog_1163_li
#The Lucene fulltext search now also returns the score.
@changelog_1158_li
@changelog_1164_li
# New function SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger.
@changelog_1159_li
@changelog_1165_li
#Statement.getGeneratedKeys() returned the wrong value if a trigger changed the identity value after inserting the row.
@changelog_1160_li
@changelog_1166_li
#Improved error messages: identifiers and values are now quoted.
@changelog_1161_li
@changelog_1167_li
#Improved error message when casting a value failed: the column name and type is included in the message.
@changelog_1162_li
@changelog_1168_li
#Improved support for GAE for Java thanks to Vince Bonfanti.
@changelog_1163_h2
@changelog_1169_h2
#Version 1.2.122 (2009-10-28)
@changelog_1164_li
@changelog_1170_li
#The native fulltext search now supports streaming CLOB data.
@changelog_1165_li
@changelog_1171_li
#If the database URL ends with ;PAGE_STORE=TRUE and a database in the old format exists, it is automatically converted to the new page store format if possible. A backup of the database is created first. Automatic conversion is not supported if the database was not closed normally (if it contains uncommitted transactions).
@changelog_1166_li
@changelog_1172_li
#Dropping the current user is now allowed if another admin user exists.
@changelog_1167_li
@changelog_1173_li
#Values of type BINARY or BLOB could not be converted to the data type OTHER.
@changelog_1168_li
@changelog_1174_li
#SHUTDOWN COMPACT now fully compacts the database.
@changelog_1169_li
@changelog_1175_li
#New system properties h2.maxCompactCount and h2.maxCompactTime to allow changing the default behavior (at most 2 seconds compacting when closing the database).
@changelog_1170_li
@changelog_1176_li
#New sorted insert optimization (see Performance / Database Performance Tuning).
@changelog_1171_li
@changelog_1177_li
#Issue 116: The files h2*-sources.jar and h2*-javadoc.jar are now in the Maven repository.
@changelog_1172_li
@changelog_1178_li
#Page store: opening a large database was slow if it was not closed before.
@changelog_1173_li
@changelog_1179_li
#Page store: new write and read counters in the meta data table. Use SELECT * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME IN( 'info.FILE_WRITE_TOTAL', 'info.FILE_WRITE', 'info.FILE_READ', 'info.CACHE_MAX_SIZE', 'info.CACHE_SIZE')
@changelog_1174_li
@changelog_1180_li
#The SQL syntax is documented using (railroad) diagrams. The diagrams are HTML.
@changelog_1175_li
@changelog_1181_li
#The documentation is no longer available in Japanese because the translation was too much out of sync. Please use the Google translation instead.
@changelog_1176_li
@changelog_1182_li
#Certain queries were not sorted if subselect queries were involved
@changelog_1177_li
@changelog_1183_li
#More bugs in the server-less multi-connection mode have been fixed: 90097 The database is read only, caches must be cleared on reconnect, etc.
@changelog_1178_h2
@changelog_1184_h2
#Version 1.2.121 (2009-10-11)
@changelog_1179_li
@changelog_1185_li
#Better support GaeVFS (Google App Engine Virtual File System) thanks to Thanks to Vince Bonfanti.
@changelog_1180_li
@changelog_1186_li
#CSVREAD didn't close the file. Thanks to Vince Bonfanti for the patch!
@changelog_1181_li
@changelog_1187_li
#If a database in the old format exists, it is now used. The system property is used for new databases, or if databases exist in both formats. In any case, the flag in the URL overrides this logic.
@changelog_1182_li
@changelog_1188_li
#Page store bugs were fixed. Large values in indexed columns could corrupt the index.
@changelog_1183_li
@changelog_1189_li
#The page store did not work when using Retrotranslator (because the Retrotranslator doesn't support Integer.reverse and Long.reverse).
@changelog_1184_li
@changelog_1190_li
#New system property h2.pageStoreTrim to disable shrinking the database when closing (disabled by default, meaning by default the database is trimmed).
@changelog_1185_h2
@changelog_1191_h2
#Version 1.2.120 (2009-10-04)
@changelog_1186_li
@changelog_1192_li
#This is a beta version.
@changelog_1187_li
@changelog_1193_li
#Large updates could throw an ArrayIndexOutOfBoundsException in RowList.writeRow.
@changelog_1188_li
@changelog_1194_li
#In version 1.2, the following system properties are now enabled by default: h2.pageStore, h2.nullConcatIsNull, h2.optimizeInList. The default value for h2.defaultMaxLengthInplaceLob is now 4096 (it was 1024 with version 1.1).
@changelog_1189_li
@changelog_1195_li
#New databases are now stored in the new 'page store' file format. Existing databases are kept in the old file format. To use the old file format, append ;PAGE_STORE=FALSE to the database URL or set the system property h2.pageStore to false.
@changelog_1190_li
@changelog_1196_li
#Issue 125: Renaming primary keys was not persistent. Fixed. Unfortunately, databases created by this version can not be opened with older versions because of this change.
@changelog_1191_li
@changelog_1197_li
#Issue 124: Hibernate schema validation failed for decimal/numeric columns. This problem is fixed in the Hibernate dialect that is included with H2 (src/tools/org/hibernate/dialect/H2Dialect.java.txt), but not in Hibernate yet.
@changelog_1192_li
@changelog_1198_li
#PostgreSQL compatibility: function LASTVAL() as an alias for IDENTITY().
@changelog_1193_li
@changelog_1199_li
#Linked tables now support default values when inserting, updating or merging.
@changelog_1194_li
@changelog_1200_li
#Bugfixes in the page store.
@changelog_1195_li
@changelog_1201_li
#Possibility to set a vendor id in Constants.java, so that unofficial builds are distinguishable from official releases.
@changelog_1196_li
@changelog_1202_li
#Allow writing to linked tables in readonly databases.
@changelog_1197_h2
@changelog_1203_h2
#Version 1.1.119 (2009-09-26)
@changelog_1198_li
@changelog_1204_li
#SQL statements in the exception message are no longer included if they contain '--hide--'.
@changelog_1199_li
@changelog_1205_li
#Temporary local tables did not always work after reconnect if AUTO_SERVER=TRUE
@changelog_1200_li
@changelog_1206_li
#New system property h2.defaultMaxLengthInplaceLob to change the default maximum size of an in-place LOB object.
@changelog_1201_li
@changelog_1207_li
#New system property h2.nullConcatIsNull to change the default null concatenation behavior. The default will be enabled in version 1.2.
@changelog_1202_li
@changelog_1208_li
#The cache algorithm TQ is disabled in this version, because it is unstable, and because the current implementation does not have any measurable advantages over the default.
@changelog_1203_li
@changelog_1209_li
#New committer: Christian Peter. He works for <a href="http://www.docware.com">Docware</a> and helped a lot finding and fixing bugs, and generally improving the database. He is now a committer.
@changelog_1204_li
@changelog_1210_li
#ChangeFileEncryption did not work with Lob subdirectories. Fixed.
@changelog_1205_li
@changelog_1211_li
#Issue 121: JaQu: new simple update and merge methods.
@changelog_1206_li
@changelog_1212_li
#Issue 120: JaQu didn't close result sets.
@changelog_1207_li
@changelog_1213_li
#Issue 119: JaQu creates wrong WHERE conditions on some inputs.
@changelog_1208_li
@changelog_1214_li
#The new page store mechanism is now alpha-level quality. The next release will most likely be "1.2.120 beta" where this mode is enabled by default. To use it right now, append ;PAGE_STORE=TRUE to the database URL. The file format of this mode will probably not change any more.
@changelog_1209_li
@changelog_1215_li
#SELECT COUNT(*) FROM SYSTEM_RANGE(...) returned the wrong result. Fixed.
@changelog_1210_li
@changelog_1216_li
#The Recover tool now also processes the log files, however applying those changes is still a manual process.
@changelog_1211_li
@changelog_1217_li
#New sample application that shows how to pass data to a trigger.
@changelog_1212_li
@changelog_1218_li
#More bugs in the server-less multi-connection mode have been fixed: On Windows, two processes could write to the same database at the same time.
@changelog_1213_li
@changelog_1219_li
#When loading triggers or other client classes (static functions, database event listener, user aggregate functions, other JDBC drivers), the database now uses the context class loader if the class could not be found using Class.forName().
@changelog_1214_li
@changelog_1220_li
#Updating many rows with the same CLOB or BLOB values could result in FileNotFoundException.
@changelog_1215_li
@changelog_1221_li
#Statement.getConnection() threw an exception if the connection was already closed.
@changelog_1216_li
@changelog_1222_li
#The native fulltext index kept a reference to a database after the database was closed.
@changelog_1217_li
@changelog_1223_li
#Non-unique in-memory hash indexes are now supported. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1218_li
@changelog_1224_li
#The optimizer does a better job for joins if indexes are missing.
@changelog_1219_h2
@changelog_1225_h2
#Version 1.1.118 (2009-09-04)
@changelog_1220_li
@changelog_1226_li
#SHOW COLUMNS only listed indexed columns.
@changelog_1221_li
@changelog_1227_li
#When calling SHUTDOWN IMMEDIATELY in the server mode, the .trace.db file was not closed.
@changelog_1222_li
@changelog_1228_li
#DatabaseMetaData.getPrimaryKeys: the wrong constraint name was reported if there was another constraint on the same table and columns.
@changelog_1223_li
@changelog_1229_li
#AUTO_INCREMENT now works in the same way in ALTER TABLE ALTER COLUMN as in CREATE TABLE (it does not create a primary key).
@changelog_1224_li
@changelog_1230_li
#Native fulltext search: before searching, FT_INIT() had to be called. This is no longer required.
@changelog_1225_li
@changelog_1231_li
#Better support GaeVFS (Google App Engine Virtual File System).
@changelog_1226_li
@changelog_1232_li
#JaQu: the plan is to support natural (pure Java / Scala) conditions such as (id == 1 && name.equals("Test")). A proof of concept decompiler is now included (it doesn't work yet).
@changelog_1227_li
@changelog_1233_li
#Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1228_li
@changelog_1234_li
#PreparedStatement.setObject now converts a java.lang.Character to a string.
@changelog_1229_li
@changelog_1235_li
#H2 Console: PierPaolo Ucchino has completed the Italian translation. Thanks a lot!
@changelog_1230_li
@changelog_1236_li
#Various tools now use Java 5 var-args, such as main the methods and SimpleResultSet.addRow.
@changelog_1231_li
@changelog_1237_li
#H2 Console: indexes of tables of non-default schemas are now also listed.
@changelog_1232_li
@changelog_1238_li
#Issue 111: Multi-version concurrency / duplicate primary key after rollback.
@changelog_1233_li
@changelog_1239_li
#Issue 110: Multi-version concurrency / wrong exception is thrown.
@changelog_1234_li
@changelog_1240_li
#Parser: sequenceName.NEXTVAL and CURRVAL did not respect the schema search path.
@changelog_1235_li
@changelog_1241_li
#Issue 101: The following sequence could throw the exception "Row not found when trying to delete": start a transaction, insert many rows, delete many rows, rollback. The number of rows depends on the cache size.
@changelog_1236_li
@changelog_1242_li
#The stack trace of very common exceptions is no longer written to the .trace.db file by default.
@changelog_1237_li
@changelog_1243_li
#An optimization for OR is implemented, but disabled by default. Expressions of the type X=1 OR X=2 are converted to X IN(1, 2). To enable, set the system property h2.optimizeInList to true before loading the H2 JDBC driver.
@changelog_1238_li
@changelog_1244_li
#An optimization for IN(..) and IN(SELECT...) is implemented, but disabled by default. To enable, set the system property h2.optimizeInList to true before loading the H2 JDBC driver. If enabled, this overrides h2.optimizeIn and h2.optimizeInJoin. Unlike now, this optimization will also speed up updates and deletes.
@changelog_1239_h2
@changelog_1245_h2
#Version 1.1.117 (2009-08-09)
@changelog_1240_li
@changelog_1246_li
#New committer: Sam Van Oort has been contributing to H2 since quite some time in many ways (on the mailing list, documentation, and in the form of patches). He is now a committer.
@changelog_1241_li
@changelog_1247_li
#JaQu: the order of the fields in the database no longer needs to match the order in the database.
@changelog_1242_li
@changelog_1248_li
#Issue 103: MVCC: the setting MAX_MEMORY_UNDO can currently not be supported when using multi-version concurrency, that means the complete undo log must fit in memory.
@changelog_1243_li
@changelog_1249_li
#LIKE: the escape mechanism can now be disable using ESCAPE ''. The default escape character can be changed using the system property h2.defaultEscape. The default is still '\' (as in MySQL and PostgreSQL).
@changelog_1244_li
@changelog_1250_li
#Views using functions were not re-evaluated when necessary.
@changelog_1245_li
@changelog_1251_li
#Improved MySQL compatibility for SHOW COLUMNS.
@changelog_1246_li
@changelog_1252_li
#Improved PostgreSQL compatibility for timestamp literals with timezone.
@changelog_1247_li
@changelog_1253_li
#Sergi Vladykin translated the error messages to Russian. Thanks a lot!
@changelog_1248_li
@changelog_1254_li
#Support for Java 6 DatabaseMetaData.getTables, getColumns, getProcedures, and getProcedureColumns.
@changelog_1249_li
@changelog_1255_li
#Issue 101: Rollback of a large transaction (more than 100000 rows) could fail.
@changelog_1250_li
@changelog_1256_li
#Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1251_li
@changelog_1257_li
#The functions LENGTH, OCTET_LENGTH, and BIT_LENGTH now return BIGINT.
@changelog_1252_li
@changelog_1258_li
#Data types CLOB and BLOB: the maximum precision was Integer.MAX_VALUE, it is now Long.MAX_VALUE.
@changelog_1253_li
@changelog_1259_li
#Multi-threaded kernel: creating and dropping temporary database objects and the potentially free pages list was not correctly synchronized. Thanks a lot to Eric Faulhaber for the test case and patch!
@changelog_1254_li
@changelog_1260_li
#Parsing SQL script files is now faster.
@changelog_1255_li
@changelog_1261_li
#CSV reading is now faster.
@changelog_1256_li
@changelog_1262_li
#SimpleResultSet.newInstance(SimpleRowSource rs) did not work.
@changelog_1257_h2
@changelog_1263_h2
#Version 1.1.116 (2009-07-18)
@changelog_1258_li
@changelog_1264_li
#Server-less multi-connection mode: more bugs are fixed.
@changelog_1259_li
@changelog_1265_li
#The built-in help (INFORMATION_SCHEMA.HELP) is smaller, shrinking the jar file size a bit.
@changelog_1260_li
@changelog_1266_li
#H2 Console: column of tables of non-default schemas are now also listed, except for schemas starting with 'INFO'.
@changelog_1261_li
@changelog_1267_li
#ALTER TABLE: removing an auto-increment or identity column didn't remove the sequence.
@changelog_1262_li
@changelog_1268_li
#Creating indexes is now a bit faster.
@changelog_1263_li
@changelog_1269_li
#PG Server: new system property h2.pgClientEncoding to explicitly set the encoding for clients that don't send the encoding (the default encoding is UTF-8). Thanks a lot to Sergi Vladykin for the patch!
@changelog_1264_li
@changelog_1270_li
#PG Server: improved compatibility by using the type ids of the PostgreSQL driver. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1265_li
@changelog_1271_li
#H2 Console: Oracle system tables are no longer listed, improving performance.
@changelog_1266_li
@changelog_1272_li
#Result sets are now read-only except if the statement or prepared statement was created with the concurrency ResultSet.CONCUR_UPDATABLE. This change is required because the old behavior (all result set are updatable) violated the JDBC spec. For backward compatibility, use the system property h2.defaultResultSetConcurrency.
@changelog_1267_li
@changelog_1273_li
#New system property h2.defaultResultSetConcurrency to change the default result set concurrency.
@changelog_1268_li
@changelog_1274_li
#JDBC: using an invalid result set type or concurrency now throws an exception.
@changelog_1269_li
@changelog_1275_li
#If a pooled connection was not closed but garbage collected, a NullPointerException could occur.
@changelog_1270_li
@changelog_1276_li
#Fulltext search: a NullPointerException was thrown when updating a value that was NULL previously.
@changelog_1271_li
@changelog_1277_li
#The Recover tool did not work with .data.db files of the wrong size.
@changelog_1272_li
@changelog_1278_li
#Triggers: if there was an exception when initializing a trigger, this exception could be hidden, and in some cases (specially when using the Lucene fulltext index mechanism) a NullPointerException was thrown later on. Now the exception that occurred on init is thrown when changing data.
@changelog_1273_li
@changelog_1279_li
#The soft-references cache (CACHE_TYPE=SOFT_LRU) could throw a NullPointerException.
@changelog_1274_li
@changelog_1280_li
#To enable the new page store mechanism, append ;PAGE_STORE=TRUE to the database URL. or set the system property h2.pageStore to true. This mechanism is still experimental, and the file format will change, but it is quite stable now.
@changelog_1275_h2
@changelog_1281_h2
#Version 1.1.115 (2009-06-21)
@changelog_1276_li
@changelog_1282_li
#The new storage mechanism is now alpha quality. To try it out, set the system property "h2.pageStore" to "true" (java -Dh2.pageStore=true). There are still bugs to be found and fixed, for example inserting many rows references a lot of main memory. Performance is currently about the same as with the regular storage mechanism, but the database file size is smaller. The file format is not stable yet.
@changelog_1277_li
@changelog_1283_li
#ALTER TABLE could throw an exception "object already exists" in some cases.
@changelog_1278_li
@changelog_1284_li
#Views: in some situations, an ArrayIndexOutOfBoundsException was thrown when using the same view concurrently.
@changelog_1279_li
@changelog_1285_li
#java.util.UUID is now supported in PreparedStatement.setObject and user defined Java functions. ResultSet.getObject() returns a java.util.UUID when using the UUID data type.
@changelog_1280_li
@changelog_1286_li
#H2 Console: the language was reset to the browser language when disconnecting.
@changelog_1281_li
@changelog_1287_li
#H2 Console: improved Polish translation.
@changelog_1282_li
@changelog_1288_li
#Server-less multi-connection mode: more bugs are fixed.
@changelog_1283_li
@changelog_1289_li
#The download page now included the SHA1 checksums.
@changelog_1284_li
@changelog_1290_li
#Shell tool: the file encoding workaround is now documented if you run java org.h2.tools.Shell -?.
@changelog_1285_li
@changelog_1291_li
#The RunScript tool and SQL statement did not work with the compression method LZF.
@changelog_1286_li
@changelog_1292_li
#Fulltext search: searching for NULL or an empty string threw an exception.
@changelog_1287_li
@changelog_1293_li
#Lucene fulltext search: FTL_DROP_ALL did not drop the triggers.
@changelog_1288_li
@changelog_1294_li
#Backup: if the database contained CLOB or BLOB data, the backup included a file entry for the LOB directory. This caused the restore to fail.
@changelog_1289_li
@changelog_1295_li
#Data types: LONG is now an alias for BIGINT.
@changelog_1290_h2
@changelog_1296_h2
#Version 1.1.114 (2009-06-01)
@changelog_1291_li
@changelog_1297_li
#ResultSetMetaData.getColumnClassName returned the wrong class for CLOB and BLOB columns.
@changelog_1292_li
@changelog_1298_li
#Fulltext search: data is no longer deleted and re-inserted if the indexed columns didn't change.
@changelog_1293_li
@changelog_1299_li
#In some situations, an ArrayIndexOutOfBoundsException was thrown when adding rows. This was caused by a bug in the b-tree code.
@changelog_1294_li
@changelog_1300_li
#Microsoft Windows Vista: when using the the installer, Vista wrote "This program may not have installed correctly." This message should no longer appear (in the h2.nsi file, the line 'RequestExecutionLevel highest' was added).
@changelog_1295_li
@changelog_1301_li
#The Recover tool did not always work when the database contains referential integrity constraints.
@changelog_1296_li
@changelog_1302_li
#Java 1.5 is now required to run H2. If required, Retrotranslator can be used to create a Java 1.4 version (http://retrotranslator.sourceforge.net/).
@changelog_1297_h2
@changelog_1303_h2
#Version 1.1.113 (2009-05-21)
@changelog_1298_li
@changelog_1304_li
#Shell tool: the built-in commands EXIT, HELP, ?, LIST, and so on didn't work with a semicolon at the end.
@changelog_1299_li
@changelog_1305_li
#JDK 1.5 is now required to build the jar file. However it is still possible to create a jar file for Java 1.4. For details, see buildRelease.sh and buildRelease.bat. As an alternative, compile using JDK 1.5 or 1.6 and use Retrotranslator to create a Java 1.4 version (http://retrotranslator.sourceforge.net/).
@changelog_1300_li
@changelog_1306_li
#When deleting or updating many rows in a table, the space in the index file was not re-used in the default mode (persistent database, b-tree index, LOG=1). This caused the index file to grow over time. Workarounds were to delete and re-created the index file, alter the table (add a remove a column), or append ;LOG=2 to the database URL. To disable the change, set the system property h2.reuseSpaceBtreeIndex to false.
@changelog_1301_li
@changelog_1307_li
#Identifiers with a digit and then a dollar sign didn't work. Example: A1$B.
@changelog_1302_li
@changelog_1308_li
#MS SQL Server compatibility: support for linked tables with NVARCHAR, NCHAR, NCLOB, and LONGNVARCHAR.
@changelog_1303_li
@changelog_1309_li
#Android: workaround for a problem when using read-only databases in zip files (skip seems to be implemented incorrectly on the Android system).
@changelog_1304_li
@changelog_1310_li
#Calling execute() or prepareStatement() with null as the SQL statement now throws an exception.
@changelog_1305_li
@changelog_1311_li
#Benchmark: the number of executed statements was incorrect. The H2 database was loaded at the beginning of the test to collect results, now it is loaded at the very end. Thanks to Fred Toussi from HSQLDB for reporting those problems. However the changed do not affect the relative performance.
@changelog_1306_li
@changelog_1312_li
#H2 Console: command line settings are no longer stored in the properties file. They are now only used for the current process, except if they are explicitly saved.
@changelog_1307_li
@changelog_1313_li
#Cache: support for a second level soft-references cache. To enable it, append ;CACHE_TYPE=SOFT_LRU (or SOFT_TQ) to the database URL, or set the system property h2.cacheTypeDefault to "SOFT_LRU" / "SOFT_TQ". Enabling the second level cache reduces performance for small databases, but speeds up large databases. It makes sense to use it if the available memory size is unknown. Thanks a lot to Jan Kotek!
@changelog_1308_h2
@changelog_1314_h2
#Version 1.1.112 (2009-05-01)
@changelog_1309_li
@changelog_1315_li
#JdbcPreparedStatement.toString() could throw a NullPointerException.
#Connection pool: the default login timeout is now 5 minutes.
@changelog_1312_li
@changelog_1318_li
#After truncating tables, opening large databases could become slow because indexes were always re-built unnecessarily when opening.
@changelog_1313_li
@changelog_1319_li
#More bugs in the server-less multi-connection mode have been fixed: Sometimes parameters of prepared statements were lost when a reconnecting. Concurrent read operations were slow. To improve performance, executeQuery(..) must be used for queries (execute(..) switches to the write mode, which is slow).
@changelog_1314_li
@changelog_1320_li
#GROUP BY queries with a self-join (join to the same table) that were grouped by columns with indexes returned the wrong result in some cases.
@changelog_1315_li
@changelog_1321_li
#Improved error message when the .lock.db file modification time is in the future.
@changelog_1316_li
@changelog_1322_li
#The MERGE statement now returns 0 as the generated key if the row was updated.
@changelog_1317_li
@changelog_1323_li
#Running code coverage is now automated.
@changelog_1318_li
@changelog_1324_li
#A file system implementation can now be registered using FileSystem.register.
@changelog_1319_li
@changelog_1325_li
#The database file system is no longer included in the jar file, it moved to the test section.
@changelog_1320_h2
@changelog_1326_h2
#Version 1.1.111 (2009-04-10)
@changelog_1321_li
@changelog_1327_li
#In-memory databases can now run inside the Google App Engine.
@changelog_1322_li
@changelog_1328_li
#Queries that are ordered by an indexed column returned no rows in certain cases (if all rows were deleted from the table previously, and there is a low number of rows in the table, and when not using other conditions, and when using the default b tree index).
@changelog_1323_li
@changelog_1329_li
#The wrong exception was thrown when using unquoted text for the SQL statements COMMENT, ALTER USER, and SET PASSWORD.
@changelog_1324_li
@changelog_1330_li
#The built-in connection pool did not roll back transactions and enable autocommit enabled after closing a connection.
@changelog_1325_li
@changelog_1331_li
#Sometimes a StackOverflow occurred when checking for deadlock. See also http://code.google.com/p/h2database/issues/detail?id=61
@changelog_1326_li
@changelog_1332_li
#The Shell tool no longer truncates results with only one column, and displays a message if data was truncated.
@cheatSheet_1000_h1
...
...
@@ -8135,43 +8153,43 @@ H2 コンソール アプリケーション
#Full outer joins.
@roadmap_1014_li
#Support mixed clustering mode (one embedded, others in server mode).
#Automatic collection of statistics (auto ANALYZE; AUTOVACUUM). See http://www.postgresql.org/docs/current/static/routine-vacuuming.html#AUTOVACUUM
@roadmap_1015_li
#PostgreSQL catalog: use BEFORE SELECT triggers instead of views over metadata tables.
#Support mixed clustering mode (one embedded, others in server mode).
@roadmap_1016_li
#Test very large databases and LOBs (up to 256 GB).
#PostgreSQL catalog: use BEFORE SELECT triggers instead of views over metadata tables.
@roadmap_1017_li
#Support hints for the optimizer (which index to use, enforce the join order).
#Test very large databases and LOBs (up to 256 GB).
@roadmap_1018_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).
#Support hints for the optimizer (which index to use, enforce the join order).
@roadmap_1019_li
#Clustering: recovery needs to becomes fully automatic. Global write lock feature.
#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).
@roadmap_1020_li
#Clustering: reads should be randomly distributed (optional) or to a designated database on RAM (parameter: READ_FROM=3).
#Clustering: recovery needs to becomes fully automatic. Global write lock feature.
@roadmap_1021_li
#Sequence: add features [NO] MINVALUE, MAXVALUE, CYCLE.
#Clustering: reads should be randomly distributed (optional) or to a designated database on RAM (parameter: READ_FROM=3).
# The <code>BACKUP</code> SQL statement and the <code>Backup</code> tool both create a zip file with all database files. However, the contents of this file are not human readable. Other than the SCRIPT statement, the <code>BACKUP</code> statement does not lock the database objects, and therefore does not block other users. The resulting backup is transactionally consistent:
# The <code>BACKUP</code> SQL statement and the <code>Backup</code> tool both create a zip file with all database files. However, the contents of this file are not human readable.
@tutorial_1138_p
# The <code>Backup</code> tool (<code>org.h2.tools.Backup</code>) can not be used to create a online backup; the database must not be in use while running this program.
# Unlike than the SCRIPT statement, the <code>BACKUP</code> statement does not lock the database objects when using the multi-threaded mode, and therefore does not block other users. The resulting backup is transactionally consistent:
@tutorial_1139_p
# Creating a backup while the database is running is not supported, except if the file systems support creating snapshots. The problem is that it can't be guaranteed that the data is copied in the right order.
# The <code>Backup</code> tool (<code>org.h2.tools.Backup</code>) can not be used to create a online backup; the database must not be in use while running this program.
@tutorial_1140_p
# Creating a backup by copying the database files while the database is running is not supported, except if the file systems support creating snapshots. The problem is that it can't be guaranteed that the data is copied in the right order.
@tutorial_1140_h2
@tutorial_1141_h2
#Command Line Tools
@tutorial_1141_p
@tutorial_1142_p
# This database comes with a number of command line tools. To get more information about a tool, start it with the parameter '-?', for example:
@tutorial_1142_p
@tutorial_1143_p
# The command line tools are:
@tutorial_1143_code
@tutorial_1144_code
バックアップ
@tutorial_1144_li
@tutorial_1145_li
# creates a backup of a database.
@tutorial_1145_code
@tutorial_1146_code
#ChangeFileEncryption
@tutorial_1146_li
@tutorial_1147_li
# allows changing the file encryption password or algorithm of a database.
@tutorial_1147_code
@tutorial_1148_code
#Console
@tutorial_1148_li
@tutorial_1149_li
# starts the browser based H2 Console.
@tutorial_1149_code
@tutorial_1150_code
#ConvertTraceFile
@tutorial_1150_li
@tutorial_1151_li
# converts a .trace.db file to a Java application and SQL script.
@tutorial_1151_code
@tutorial_1152_code
#CreateCluster
@tutorial_1152_li
@tutorial_1153_li
# creates a cluster from a standalone database.
@tutorial_1153_code
@tutorial_1154_code
#DeleteDbFiles
@tutorial_1154_li
@tutorial_1155_li
# deletes all files belonging to a database.
@tutorial_1155_code
@tutorial_1156_code
#Recover
@tutorial_1156_li
@tutorial_1157_li
# helps recovering a corrupted database.
@tutorial_1157_code
@tutorial_1158_code
#Restore
@tutorial_1158_li
@tutorial_1159_li
# restores a backup of a database.
@tutorial_1159_code
@tutorial_1160_code
#RunScript
@tutorial_1160_li
@tutorial_1161_li
# runs a SQL script against a database.
@tutorial_1161_code
@tutorial_1162_code
#Script
@tutorial_1162_li
@tutorial_1163_li
# allows converting a database to a SQL script for backup or migration.
@tutorial_1163_code
@tutorial_1164_code
Server
@tutorial_1164_li
@tutorial_1165_li
# is used in the server mode to start a H2 server.
@tutorial_1165_code
@tutorial_1166_code
#Shell
@tutorial_1166_li
@tutorial_1167_li
# is a command line database tool.
@tutorial_1167_p
@tutorial_1168_p
# The tools can also be called from an application by calling the main or another public method. For details, see the Javadoc documentation.
@tutorial_1168_h2
@tutorial_1169_h2
#The Shell Tool
@tutorial_1169_p
@tutorial_1170_p
# The Shell tool is a simple interactive command line tool. To start it, type:
@tutorial_1170_p
@tutorial_1171_p
# You will be asked for a database URL, JDBC driver, user name, and password. The connection setting can also be set as command line parameters. After connecting, you will get the list of options. The built-in commands don't need to end with a semicolon, but SQL statements are only executed if the line ends with a semicolon <code>;</code>. This allows to enter multi-line statements:
@tutorial_1171_p
@tutorial_1172_p
# By default, results are printed as a table. For results with many column, consider using the list mode:
@tutorial_1172_h2
@tutorial_1173_h2
OpenOffice Baseを使用する
@tutorial_1173_p
@tutorial_1174_p
# OpenOffice.org Base supports database access over the JDBC API. To connect to a H2 database using OpenOffice Base, you first need to add the JDBC driver to OpenOffice. The steps to connect to a H2 database are:
@tutorial_1174_li
@tutorial_1175_li
#Start OpenOffice Writer, go to [Tools], [Options]
@tutorial_1175_li
@tutorial_1176_li
#Make sure you have selected a Java runtime environment in OpenOffice.org / Java
@tutorial_1176_li
@tutorial_1177_li
#Click [Class Path...], [Add Archive...]
@tutorial_1177_li
@tutorial_1178_li
#Select your h2 jar file (location is up to you, could be wherever you choose)
@tutorial_1178_li
@tutorial_1179_li
#Click [OK] (as much as needed), stop OpenOffice (including the Quickstarter)
@tutorial_1179_li
@tutorial_1180_li
#Start OpenOffice Base
@tutorial_1180_li
@tutorial_1181_li
#Connect to an existing database; select [JDBC]; [Next]
# This can be done by create it using the NetBeans OpenOffice plugin. See also <a href="http://wiki.services.openoffice.org/wiki/Extensions_development_java">Extensions Development</a>.
@tutorial_1199_h2
@tutorial_1200_h2
Java Web Start / JNLP
@tutorial_1200_p
@tutorial_1201_p
# When using Java Web Start / JNLP (Java Network Launch Protocol), permissions tags must be set in the .jnlp file, and the application .jar file must be signed. Otherwise, when trying to write to the file system, the following exception will occur: <code>java.security.AccessControlException</code>: access denied (<code>java.io.FilePermission ... read</code>). Example permission tags:
@tutorial_1201_h2
@tutorial_1202_h2
#Using a Connection Pool
@tutorial_1202_p
@tutorial_1203_p
# For H2, opening a connection is fast if the database is already open. Still, using a connection pool improves performance if you open and close connections a lot. A simple connection pool is included in H2. It is based on the <a href="http://www.source-code.biz/snippets/java/8.htm">Mini Connection Pool Manager</a> from Christian d'Heureuse. There are other, more complex, open source connection pools available, for example the <a href="http://jakarta.apache.org/commons/dbcp/">Apache Commons DBCP</a>. For H2, it is about twice as faster to get a connection from the built-in connection pool than to get one using <code>DriverManager.getConnection()</code>.The build-in connection pool is used as follows:
@tutorial_1203_h2
@tutorial_1204_h2
フルテキストサーチ
@tutorial_1204_p
@tutorial_1205_p
# H2 includes two fulltext search implementations. One is using Apache Lucene, and the other (the native implementation) stores the index data in special tables in the database.
@tutorial_1205_h3
@tutorial_1206_h3
#Using the Native Fulltext Search
@tutorial_1206_p
@tutorial_1207_p
# To initialize, call:
@tutorial_1207_p
@tutorial_1208_p
# You need to initialize it in each database where you want to use it. Afterwards, you can create a fulltext index for a table using:
@tutorial_1208_p
@tutorial_1209_p
# PUBLIC is the schema name, 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 realtime. To search the index, use the following query:
@tutorial_1209_p
@tutorial_1210_p
# This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1210_p
@tutorial_1211_p
# To get the raw data, use <code>FT_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in: <code>SELECT T.* FROM FT_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID=FT.KEYS[0];</code>
@tutorial_1211_p
@tutorial_1212_p
# You can also call the index from within a Java application:
@tutorial_1212_h3
@tutorial_1213_h3
Luceneフルテキストサーチを使用する
@tutorial_1213_p
@tutorial_1214_p
# To use the Lucene full text search, you need the Lucene library in the classpath. How to do that depends on the application; if you use the H2 Console, you can add the Lucene jar file to the environment variables <code>H2DRIVERS</code> or <code>CLASSPATH</code>. To initialize the Lucene fulltext search in a database, call:
@tutorial_1214_p
@tutorial_1215_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_1215_p
@tutorial_1216_p
# PUBLIC is the schema name, 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 realtime. To search the index, use the following query:
@tutorial_1216_p
@tutorial_1217_p
# This will produce a result set that contains the query needed to retrieve the data:
@tutorial_1217_p
@tutorial_1218_p
# To get the raw data, use <code>FTL_SEARCH_DATA('Hello', 0, 0);</code>. The result contains the columns <code>SCHEMA</code> (the schema name), <code>TABLE</code> (the table name), <code>COLUMNS</code> (an array of column names), and <code>KEYS</code> (an array of objects). To join a table, use a join as in: <code>SELECT T.* FROM FTL_SEARCH_DATA('Hello', 0, 0) FT, TEST T WHERE FT.TABLE='TEST' AND T.ID=FT.KEYS[0];</code>
@tutorial_1218_p
@tutorial_1219_p
# You can also call the index from within a Java application:
@tutorial_1219_h2
@tutorial_1220_h2
#User-Defined Variables
@tutorial_1220_p
@tutorial_1221_p
# This database supports user-defined variables. Variables start with <code>@</code> and can be used wherever expressions or parameters are allowed. Variables are not persisted and session scoped, that means only visible from within the session in which they are defined. A value is usually assigned using the SET command:
@tutorial_1221_p
@tutorial_1222_p
# The value can also be changed using the SET() method. This is useful in queries:
@tutorial_1222_p
@tutorial_1223_p
# Variables that are not set evaluate to <code>NULL</code>. The data type of a user-defined variable is the data type of the value assigned to it, that means it is not necessary (or possible) to declare variable names before using them. There are no restrictions on the assigned values; large objects (LOBs) are supported as well.
@tutorial_1223_h2
@tutorial_1224_h2
#Date and Time
@tutorial_1224_p
@tutorial_1225_p
# Date, time and timestamp values support ISO 8601 formatting, including time zone:
@tutorial_1225_p
@tutorial_1226_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 <code>SCRIPT</code> command or <code>Script</code> tool, and then load the database using the <code>RUNSCRIPT</code> command or the <code>RunScript</code> tool in the new time zone.
@tutorial_1226_h2
@tutorial_1227_h2
#Using Spring
@tutorial_1227_p
@tutorial_1228_p
# Use the following configuration to start and stop the H2 TCP server using the Spring Framework:
@tutorial_1228_p
@tutorial_1229_p
# The <code>destroy-method</code> will help prevent exceptions on hot-redeployment or when restarting the server.
