@@ -37,7 +37,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
<h2>Priority 2</h2>
<ul><li>Improve test code coverage.
</li><li>Automatic collection of statistics (auto ANALYZE; AUTOVACUUM). See http://www.postgresql.org/docs/current/static/routine-vacuuming.html#AUTOVACUUM
</li><li>Test multi-threaded in-memory db access
</li><li>MVCC: select for update should only lock the selected rows.
</li><li>Option to shutdown all the running servers (on the same VM).
There is a list of keywords that can't be used as identifiers (table names, column names and so on), unless they are quoted (surrounded with double quotes). The list is currently:
@advanced_1120_code
CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT, EXISTS, FALSE, FOR, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, WHERE
CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT, EXISTS, FALSE, FOR, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, UNIQUE, WHERE
@advanced_1121_p
Certain words of this list are keywords because they are functions that can be used without '()' for compatibility, for example <code>CURRENT_TIMESTAMP</code>.
...
...
@@ -1399,1021 +1399,1045 @@ Change Log
@changelog_1001_h2
Next Version (unreleased)
@changelog_1002_h2
Version 1.2.134 (2010-04-23)
@changelog_1002_li
Global temporary tables are now deleted when closing the database. Before, they were deleted when opening the database the next time.
@changelog_1003_li
New system property h2.analyzeAuto (default 0 meaning disabled) to automatically run ANALYZE after that many changes to a table. For details, see the Javadoc of this system property. The plan is to set this property to 2000 in version 1.3.x.
UNIQUE was not listed as a keyword.
@changelog_1004_li
JdbcXAConnection.start() does not support TMJOIN. Issue 189.
Improved error message when an non-SQL-exception occurred in a user defined function. The method name and parameters are included in the error message.
@changelog_1005_li
MySQL compatibility: TIMESTAMPDIFF is now an alias for DATEDIFF.
For some queries, the exception did not include the SQL statement. Example: select x from system_range(1, 2) group by 'a'.
@changelog_1006_li
MERGE did not respect foreign key and check constraints.
The Shell tool will execute SQL statements passed as using the command line parameter -sql.
@changelog_1007_li
ALTER TABLE ALTER COLUMN: changing the data type of a column no longer makes it nullable.
If InetAddress.getLocalHost() fails, the database should now throw an exception.
@changelog_1008_li
When using AUTO_SERVER=TRUE, the server is now started as a daemon thread. This was a problem when using Tomcat and a connection pool.
New columns INFORMATION_SCHEMA.INDEXES.INDEX_CLASS and INFORMATION_SCHEMA.TABLES.TABLE_CLASS.
@changelog_1009_li
INFORMATION_SCHEMA.INDEXES.SQL now contains the CREATE INDEX statement instead of just the fully qualified index name.
@changelog_1010_h2
Version 1.2.134 (2010-04-23)
@changelog_1011_li
New system property h2.analyzeAuto (default 0 meaning disabled) to automatically run ANALYZE after that many changes to a table. For details, see the Javadoc of this system property. The plan is to set this property to 2000 in version 1.3.x.
@changelog_1012_li
JdbcXAConnection.start() does not support TMJOIN. Issue 189.
@changelog_1013_li
MySQL compatibility: TIMESTAMPDIFF is now an alias for DATEDIFF.
@changelog_1014_li
MERGE did not respect foreign key and check constraints.
@changelog_1015_li
ALTER TABLE ALTER COLUMN: changing the data type of a column no longer makes it nullable.
@changelog_1016_li
When using AUTO_SERVER=TRUE, the server is now started as a daemon thread. This was a problem when using Tomcat and a connection pool.
@changelog_1017_li
Servers can now be started as a daemon thread using the command line options -tcpDaemon, -pgDaemon, and -webDaemon.
@changelog_1010_li
@changelog_1018_li
H2 Console: the built-in commands are now documented.
@changelog_1011_li
@changelog_1019_li
REPLACE: if any parameter is null, the result is null.
@changelog_1012_li
@changelog_1020_li
Queries with DISTINCT and ORDER BY will now use the index on ORDER BY if possible. This is specially important for queries used inside IN(SELECT ...).
@changelog_1013_li
@changelog_1021_li
The new statement EXPLAIN ANALYZE executes the statement, and displays the query plan with the actual row scan count for each table.
@changelog_1014_li
@changelog_1022_li
H2 Console: the auto-complete feature didn't quote column names that need quoting. Issue 186.
@changelog_1015_li
@changelog_1023_li
The experimental LOB storage mechanism now supports all features of the old one. To use it, set the system property "h2.lobInDatabase" to "true". If you have used this feature in version 1.2.133, you need to export and re-import the database using SCRIPT / RUNSCRIPT.
@changelog_1016_li
@changelog_1024_li
The functions isBeforeFirst() and isAfterLast() were not compliant to the JDBC spec. If the ResultSet contains no rows, they must return false. Fixed.
@changelog_1017_li
@changelog_1025_li
Filesystem parameters like "split:" didn't work in server mode with baseDir set.
@changelog_1018_li
@changelog_1026_li
If baseDir is set, and a database name is given which points to a directory outside the baseDir (eg. "../dbname"), an exception is thrown.
@changelog_1019_h2
@changelog_1027_h2
Version 1.2.133 (2010-04-10)
@changelog_1020_li
@changelog_1028_li
A new experimental LOB storage mechanism is available. When enabled, CLOB and BLOB data is stored in hidden tables in the database. To use it, set the system property "h2.lobInDatabase" to "true". Compression is not yet implemented. Duplicate objects are only stored once. Usually writing is slower, but reading is faster (mainly because of caching).
@changelog_1021_li
@changelog_1029_li
The Shell tool threw a NumberFormatException on a empty statement.
@changelog_1022_li
@changelog_1030_li
The h2small-*.jar did not support "drop all objects delete files". Now it is supported (the DeleteDbFiles tool is now included).
@changelog_1023_li
@changelog_1031_li
Operations that don't fit in memory are now faster. Temporary file handling was changed.
@changelog_1024_li
@changelog_1032_li
The default maximum log stream size is now 2 MB. This is a good value according to some performance tests.
@changelog_1025_li
@changelog_1033_li
New system property "h2.syncMethod" to configure what method to call when closing the database, on checkpoint, and on CHECKPOINT SYNC. The default is "sync" which calls RandomAccessFile.getFD().sync().
@changelog_1026_li
@changelog_1034_li
ROWNUM could not be used for pagination. The follow query returned no rows: select x from (select *, rownum as r from system_range(1, 3)) where r=2;
@changelog_1027_li
@changelog_1035_li
Workaround for a java.sql.Date issue: years above 9999 are not formatted correctly. When calling ResultSet.getString() on a date value, an alternative formatting algorithm is used.
@changelog_1028_li
@changelog_1036_li
Prepared statements with nested subqueries did not always return the correct result. Example: select ?, ?, (select count(*) from test t, (select id from test where 0=?) t2 where t2.id=t.id) from test
@changelog_1029_li
@changelog_1037_li
When using MULTI_THREADED=TRUE, the exception following exception could be thrown: "object already exists: TABLES"
@changelog_1030_li
@changelog_1038_li
Comparison of integer columns against float numbers was not always correct. Issue 182.
@changelog_1031_li
@changelog_1039_li
H2 Console: Editing the result of a multi-line queries failed. Issue 183.
@changelog_1032_li
@changelog_1040_li
H2 Console: if the settings file (.h2.properties) can't be accessed, the exception is now ignored.
@changelog_1033_h2
@changelog_1041_h2
Version 1.2.132 (2010-03-21)
@changelog_1034_li
@changelog_1042_li
The implementation of a Java to C (source code level) converter has been started. The plan is: it should be possible to convert H2 (or a part of it) to C so that the database can be run without a JVM. This will be a long term project (it may take a year or so).
@changelog_1035_li
@changelog_1043_li
User defined table implementation can now be used using CREATE TABLE ... ENGINE. Thanks to Sergi Vladykin for implementing this feature!
@changelog_1036_li
@changelog_1044_li
Improved MS SQL Server compatibility: support string concatenation using "+". Thanks to Stepan for the patch!
@changelog_1037_li
@changelog_1045_li
When using the multi-threaded mode, running ANALYZE concurrently in multiple connections could throw an exception.
@changelog_1038_li
@changelog_1046_li
The MERGE statement is now about 30% faster when using a PreparedStatement.
@changelog_1039_li
@changelog_1047_li
Multi-column indexes where the second or later column was descending did not always produce correct results (rows were missing in the result set, or the result set was empty).
@changelog_1040_li
@changelog_1048_li
When using large transactions or a small log size, the database could get very slow (profiling shows the hotspot is in FileObjectDisk.sync()).
@changelog_1041_li
@changelog_1049_li
The Shell tool now prints the stack trace when the list mode is enabled.
@changelog_1042_li
@changelog_1050_li
CREATE ALIAS ... AS: Compilation was incorrect if the source code contained characters that are not supported by the default file encoding.
@changelog_1043_li
@changelog_1051_li
Issue 176: the JdbcDataSource now also supports a 'description' property.
@changelog_1044_li
@changelog_1052_li
The Shell tool threw a ArrayIndexOutOfBoundsException after 20 statements.
@changelog_1045_li
@changelog_1053_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_1046_li
@changelog_1054_li
Literals of type BIGINT now have the correct data type.
@changelog_1047_h2
@changelog_1055_h2
Version 1.2.131 (2010-03-05)
@changelog_1048_li
@changelog_1056_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_1049_li
@changelog_1057_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_1050_li
@changelog_1058_li
After the database was closed, a null pointer exception could occur in Database.flush.
@changelog_1051_li
@changelog_1059_li
An ArrayIndexOutOfBoundsException could occur in the page store (eg. on "delete from table"). Fixed.
@changelog_1052_h2
@changelog_1060_h2
Version 1.2.130 (2010-02-26)
@changelog_1053_li
@changelog_1061_li
EXPLAIN: The query plan now contains ".tableScan" if a table scan is used.
@changelog_1054_li
@changelog_1062_li
IN(..): when combining and IN(..) condition with a condition that didn't use an index, the result could contain duplicate rows.
@changelog_1055_li
@changelog_1063_li
IN(..): the index was not used if there were multiple IN(..) conditions.
@changelog_1056_li
@changelog_1064_li
For foreign key constraints, the metadata column INFORMATION_SCHEMA.INDEXES.CONSTRAINT_NAME was not set for non-unique indexes.
@changelog_1057_li
@changelog_1065_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_1058_li
@changelog_1066_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_1059_li
@changelog_1067_li
When using temporary tables, the database didn't shrink sometimes when closing. Also, sometimes a database could not recover normally.
@changelog_1060_li
@changelog_1068_li
Large transactions could run out of heap space. The maximum size of a transaction is now much larger.
@changelog_1061_li
@changelog_1069_li
The default setting for the system property h2.webMaxValueLength is now 100000 (it was 10000 before).
@changelog_1062_li
@changelog_1070_li
Creating a database was delayed about 2 seconds if the directory didn't exist.
@changelog_1063_li
@changelog_1071_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_1064_h2
@changelog_1072_h2
Version 1.2.129 (2010-02-19)
@changelog_1065_li
@changelog_1073_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_1066_li
@changelog_1074_li
CREATE ALIAS: error message when compiling Java code have been improved.
@changelog_1067_li
@changelog_1075_li
MVCC: creating a table with an incorrect constraint could cause strange errors.
@changelog_1068_li
@changelog_1076_li
Hash indexes now are only used for single column indexes.
@changelog_1069_li
@changelog_1077_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_1070_li
@changelog_1078_li
The file system abstraction no longer throws SQL exceptions.
@changelog_1071_li
@changelog_1079_li
DatabaseEventListener.diskSpaceIsLow has changed.
@changelog_1072_li
@changelog_1080_li
The CompressTool no longer throw as SQL exceptions. Instead, it throws runtime exceptions.
@changelog_1073_li
@changelog_1081_li
SimpleResultSet.addColumn and addRow now can throw a IllegalStateException instead of a SQLException.
@changelog_1074_li
@changelog_1082_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_1075_li
@changelog_1083_li
The BNF parser now uses the visitor pattern.
@changelog_1076_li
@changelog_1084_li
Converting a UUID to bytes was incorrect. Because of that, updatable result sets on tables with UUID primary key did not work.
@changelog_1077_li
@changelog_1085_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_1078_li
@changelog_1086_li
H2 Console: asynchronous login (using a DatabaseEventListener) is no longer supported.
@changelog_1079_li
@changelog_1087_li
A workaround for a Windows socket problem has been implemented. Thanks a lot to Sergi Vladykin.
@changelog_1080_li
@changelog_1088_li
The Recover tool did not convert correctly convert CLOB data with non-ASCII characters.
@changelog_1081_li
@changelog_1089_li
Tools: the method run(String... args) has been renamed to runTool(String... args).
@changelog_1082_li
@changelog_1090_li
Server.startWebServer(Connection) was not working as expected.
@changelog_1083_li
@changelog_1091_li
The database URL option ACCESS_MODE_LOG is no longer supported.
@changelog_1084_li
@changelog_1092_li
The database URL option RECOVER has currently no effect.
@changelog_1085_li
@changelog_1093_li
Converting an old (non-page store) database is no longer supported using this version.
@changelog_1086_li
@changelog_1094_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_1087_li
@changelog_1095_li
The setting LOG has currently no effect (it only had an effect when the page store was disabled).
@changelog_1088_li
@changelog_1096_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_1089_li
@changelog_1097_li
The translated resources are now stored in UTF-8 format.
@changelog_1090_li
@changelog_1098_li
The Windows service wrapper now detects if multiple versions of H2 are installed.
@changelog_1091_h2
@changelog_1099_h2
Version 1.2.128 (2010-01-30)
@changelog_1092_li
@changelog_1100_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_1093_li
@changelog_1101_li
The DeleteDbFiles tool deleted all files in the .lob.db directory, even files that didn't belong to the database.
@changelog_1094_li
@changelog_1102_li
Automatic conversion of old databases to the page store format failed if the database contained LOB files.
@changelog_1095_li
@changelog_1103_li
Nested subqueries didn't work for INSERT INTO and IN(..). Example: insert into test ((select 1));
@changelog_1096_li
@changelog_1104_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_1097_li
@changelog_1105_li
Less classes are loaded when using the database in embedded mode.
@changelog_1098_li
@changelog_1106_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_1099_li
@changelog_1107_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_1100_li
@changelog_1108_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_1101_li
@changelog_1109_li
Improved PostgreSQL compatibility (support SHOW DEFAULT_TRANSACTION_ISOLATION).
@changelog_1102_li
@changelog_1110_li
Documentation: the javadocs for Csv.write and read used the wrong default charset.
@changelog_1103_li
@changelog_1111_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_1104_li
@changelog_1112_li
If a FOR UPDATE query was executed twice (using a PreparedStatement), the table was not locked.
@changelog_1105_li
@changelog_1113_li
Triggers: INSTEAD OF triggers are now supported. Such triggers can be defined on views.
@changelog_1106_li
@changelog_1114_li
New system property h2.identifiersToUpper. If set to false, identifiers in SQL statements are case sensitive even if they are not quoted.
@changelog_1107_li
@changelog_1115_li
Slightly improved performance if the table is already locked.
@changelog_1108_li
@changelog_1116_li
CompressLZF: faster decompression.
@changelog_1109_li
@changelog_1117_li
PgServer: the wrong size was sent for VARCHAR data. Thanks again to Sergi Vladykin for the patch.
@changelog_1110_li
@changelog_1118_li
Serialized access mode (server-less multi-connection mode): fixed getGeneratedKeys() for sequences.
@changelog_1111_h2
@changelog_1119_h2
Version 1.2.127 (2010-01-15)
@changelog_1112_li
@changelog_1120_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_1113_li
@changelog_1121_li
Page store: new databases can not be opened with older versions.
@changelog_1114_li
@changelog_1122_li
Page store: adding data to new database is now faster.
@changelog_1115_li
@changelog_1123_li
File system: getting the file name from a path is now faster. This should speed up BLOB and CLOB access.
@changelog_1116_li
@changelog_1124_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_1117_li
@changelog_1125_li
SHOW COLUMNS did not work correctly if there where multiple indexes on the same columns.
@changelog_1118_li
@changelog_1126_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_1119_li
@changelog_1127_li
Result sets larger than 2 GB threw an exception "Negative seek offset". Fixed.
@changelog_1120_li
@changelog_1128_li
If the system property h2.check was set to false, an ArrayIndexOutOfBoundsException could occur.
@changelog_1121_li
@changelog_1129_li
Alter table is now supported even if a table has views defined.
@changelog_1122_li
@changelog_1130_li
Fulltext search: exceptions within the fulltext search package had the wrong SQL state.
@changelog_1123_li
@changelog_1131_li
The Lucene fulltext search ignored transaction rollback. Fixed using a trigger on rollback.
@changelog_1124_li
@changelog_1132_li
Trigger can now be called on rollback.
@changelog_1125_li
@changelog_1133_li
The shell script h2.sh ignored command line line arguments.
@changelog_1126_li
@changelog_1134_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_1127_li
@changelog_1135_li
The user home directory prefix (~) is now only expanded when followed by a slash or backslash, or standing alone.
@changelog_1128_li
@changelog_1136_li
Native fulltext search: before inserting or deleting data, FT_INIT() had to be called. This is no longer required.
@changelog_1129_li
@changelog_1137_li
The .trace.db file is now only created if required.
@changelog_1130_li
@changelog_1138_li
Shell tool: improved PostgreSQL compatibility.
@changelog_1131_li
@changelog_1139_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_1132_li
@changelog_1140_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_1133_li
@changelog_1141_li
Faster data conversion from BIGINT or INT to DECIMAL.
@changelog_1134_li
@changelog_1142_li
Server-less multi-connection mode: try to delete log files if switching between read/write operations.
@changelog_1135_li
@changelog_1143_li
CompressLZF: Faster decompress and improved javadocs
@changelog_1136_h2
@changelog_1144_h2
Version 1.2.126 (2009-12-18)
@changelog_1137_li
@changelog_1145_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_1138_li
@changelog_1146_li
CSVREAD: when reading the column names from the CSV file, column names that contain no special characters are considered case insensitive now.
@changelog_1139_li
@changelog_1147_li
Optimization index conditions of the form 'column=NULL' (which is always false; unlike 'column IS NULL').
@changelog_1140_li
@changelog_1148_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_1141_li
@changelog_1149_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_1142_li
@changelog_1150_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_1143_li
@changelog_1151_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_1144_li
@changelog_1152_li
JaQu: the decompiler has been improved, and a few test cases already work. It is still incomplete however.
@changelog_1145_li
@changelog_1153_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_1146_li
@changelog_1154_li
The reserve heap memory is no longer used.
@changelog_1147_li
@changelog_1155_li
Database.checkpoint() could throw a NullPointerException.
@changelog_1148_h2
@changelog_1156_h2
Version 1.2.125 (2009-12-06)
@changelog_1149_li
@changelog_1157_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_1150_li
@changelog_1158_li
The shell tool now has a very simple statement history.
@changelog_1151_li
@changelog_1159_li
The zip file system implementation now supports the '~' home directory prefix. Example database URL: jdbc:h2:zip:~/test.zip!/test
@changelog_1152_li
@changelog_1160_li
Right outer joins on tables that were already 'inner joined' was processed incorrectly.
@changelog_1153_li
@changelog_1161_li
Temporary files from LOB objects were not deleted early enough when using the server mode.
@changelog_1154_li
@changelog_1162_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_1155_li
@changelog_1163_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_1156_li
@changelog_1164_li
Trigger that are called before a select statement are now supported. This allows to create tables that work like materialized views.
@changelog_1157_li
@changelog_1165_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_1158_li
@changelog_1166_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_1159_li
@changelog_1167_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_1160_li
@changelog_1168_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_1161_li
@changelog_1169_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_1162_li
@changelog_1170_li
The test cases don't access the file system directly, this simplifies GAE for Java testing. Thanks to Vince Bonfanti.
@changelog_1163_li
@changelog_1171_li
More bugs in the server-less multi-connection mode have been fixed.
@changelog_1164_li
@changelog_1172_li
When running against an old database, the SCRIPT statement could generate a SQL script that contained duplicate indexes (PRIMARY_KEY_E).
@changelog_1165_li
@changelog_1173_li
JdbcConnectionPool.getConnection() could throw a NullPointerException.
@changelog_1166_li
@changelog_1174_li
User defined functions: the source code is now available using SELECT SOURCE FROM INFORMATION_SCHEMA.FUNCTION_ALIASES.
@changelog_1167_li
@changelog_1175_li
User defined functions with source code didn't work after re-opening the database.
@changelog_1168_li
@changelog_1176_li
The newsfeeds are now Atom 1.0 standard compliant.
@changelog_1169_li
@changelog_1177_li
The database is now closed after an out of memory exception, because the database could get corrupt otherwise.
@changelog_1170_li
@changelog_1178_li
Better error message if both AUTO_SERVER and SERIALIZED parameters are set to TRUE.
@changelog_1171_li
@changelog_1179_li
Drop table did not delete lob files in old file store (not PAGE_STORE).
@changelog_1172_h2
@changelog_1180_h2
Version 1.2.124 (2009-11-20)
@changelog_1173_li
@changelog_1181_li
Clustering: there is now a way to detect which cluster instances are running.
@changelog_1174_li
@changelog_1182_li
ConvertTraceFile: the SQL statement statistics are better formatted (newline are removed).
@changelog_1175_li
@changelog_1183_li
The file lock thread is now stopped when the database is closed.
@changelog_1176_li
@changelog_1184_li
Issue 140: the Script tool now supports writing to a stream.
@changelog_1177_li
@changelog_1185_li
Issue 138: the trace output of Statement.execute(String, int) and executeUpdate was incorrect.
@changelog_1178_li
@changelog_1186_li
Page store: new databases can not be opened with older versions.
@changelog_1179_li
@changelog_1187_li
Page store: multi-column indexes didn't work if the cache was very small.
@changelog_1180_li
@changelog_1188_li
Page store: opening a database could theoretically result in an endless loop.
@changelog_1181_li
@changelog_1189_li
Page store: adding large indexed columns could get very slow.
@changelog_1182_li
@changelog_1190_li
Page store: after a duplicate key exception, an ArrayIndexOutOfBoundsException could be thrown (only for very large rows).
@changelog_1183_li
@changelog_1191_li
Page store: the recover tool sometimes generated a script file that contained duplicate data.
@changelog_1184_li
@changelog_1192_li
Page store: sometimes opening a read-only database failed.
@changelog_1185_li
@changelog_1193_li
Page store: opening a database sometimes failed if large rows where updated, or if a table was truncated before.
@changelog_1186_li
@changelog_1194_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_1187_li
@changelog_1195_li
Page store: getting the min value from a descending index with NULL entries could return the wrong result.
@changelog_1188_li
@changelog_1196_li
Page store: improved auto-recovery after power failure.
@changelog_1189_li
@changelog_1197_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_1190_li
@changelog_1198_li
User defined functions can be created with source code. Example: CREATE ALIAS HI AS 'String hi() { return "Hello"; }'
@changelog_1191_li
@changelog_1199_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_1192_li
@changelog_1200_li
Inserting LOBs got slower each time the process was restarted. It could loop endlessly after about 1000 process restarts.
@changelog_1193_li
@changelog_1201_li
Issue 117: Multi-version concurrency: concurrent MERGE statements now work.
@changelog_1194_li
@changelog_1202_li
Improved read-only database detection.
@changelog_1195_h2
@changelog_1203_h2
Version 1.2.123 (2009-11-08)
@changelog_1196_li
@changelog_1204_li
Page store: new databases can not be opened with older versions.
@changelog_1197_li
@changelog_1205_li
Page store: updating large rows (rows with more than 2000 bytes of data) could corrupt the database.
@changelog_1198_li
@changelog_1206_li
Page store: inserting very large rows failed with ArrayIndexOutOfBoundsException.
@changelog_1199_li
@changelog_1207_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_1200_li
@changelog_1208_li
The fulltext search methods and fields are now protected instead of private, to make the classes more easily extensible.
@changelog_1201_li
@changelog_1209_li
The Lucene fulltext search now also returns the score.
@changelog_1202_li
@changelog_1210_li
New function SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger.
@changelog_1203_li
@changelog_1211_li
Statement.getGeneratedKeys() returned the wrong value if a trigger changed the identity value after inserting the row.
@changelog_1204_li
@changelog_1212_li
Improved error messages: identifiers and values are now quoted.
@changelog_1205_li
@changelog_1213_li
Improved error message when casting a value failed: the column name and type is included in the message.
@changelog_1206_li
@changelog_1214_li
Improved support for GAE for Java thanks to Vince Bonfanti.
@changelog_1207_h2
@changelog_1215_h2
Version 1.2.122 (2009-10-28)
@changelog_1208_li
@changelog_1216_li
The native fulltext search now supports streaming CLOB data.
@changelog_1209_li
@changelog_1217_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_1210_li
@changelog_1218_li
Dropping the current user is now allowed if another admin user exists.
@changelog_1211_li
@changelog_1219_li
Values of type BINARY or BLOB could not be converted to the data type OTHER.
@changelog_1212_li
@changelog_1220_li
SHUTDOWN COMPACT now fully compacts the database.
@changelog_1213_li
@changelog_1221_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_1214_li
@changelog_1222_li
New sorted insert optimization (see Performance / Database Performance Tuning).
@changelog_1215_li
@changelog_1223_li
Issue 116: The files h2*-sources.jar and h2*-javadoc.jar are now in the Maven repository.
@changelog_1216_li
@changelog_1224_li
Page store: opening a large database was slow if it was not closed before.
@changelog_1217_li
@changelog_1225_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_1218_li
@changelog_1226_li
The SQL syntax is documented using (railroad) diagrams. The diagrams are HTML.
@changelog_1219_li
@changelog_1227_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_1220_li
@changelog_1228_li
Certain queries were not sorted if subselect queries were involved
@changelog_1221_li
@changelog_1229_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_1222_h2
@changelog_1230_h2
Version 1.2.121 (2009-10-11)
@changelog_1223_li
@changelog_1231_li
Better support GaeVFS (Google App Engine Virtual File System) thanks to Thanks to Vince Bonfanti.
@changelog_1224_li
@changelog_1232_li
CSVREAD didn't close the file. Thanks to Vince Bonfanti for the patch!
@changelog_1225_li
@changelog_1233_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_1226_li
@changelog_1234_li
Page store bugs were fixed. Large values in indexed columns could corrupt the index.
@changelog_1227_li
@changelog_1235_li
The page store did not work when using Retrotranslator (because the Retrotranslator doesn't support Integer.reverse and Long.reverse).
@changelog_1228_li
@changelog_1236_li
New system property h2.pageStoreTrim to disable shrinking the database when closing (disabled by default, meaning by default the database is trimmed).
@changelog_1229_h2
@changelog_1237_h2
Version 1.2.120 (2009-10-04)
@changelog_1230_li
@changelog_1238_li
This is a beta version.
@changelog_1231_li
@changelog_1239_li
Large updates could throw an ArrayIndexOutOfBoundsException in RowList.writeRow.
@changelog_1232_li
@changelog_1240_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_1233_li
@changelog_1241_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_1234_li
@changelog_1242_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_1235_li
@changelog_1243_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_1236_li
@changelog_1244_li
PostgreSQL compatibility: function LASTVAL() as an alias for IDENTITY().
@changelog_1237_li
@changelog_1245_li
Linked tables now support default values when inserting, updating or merging.
@changelog_1238_li
@changelog_1246_li
Bugfixes in the page store.
@changelog_1239_li
@changelog_1247_li
Possibility to set a vendor id in Constants.java, so that unofficial builds are distinguishable from official releases.
@changelog_1240_li
@changelog_1248_li
Allow writing to linked tables in readonly databases.
@changelog_1241_h2
@changelog_1249_h2
Version 1.1.119 (2009-09-26)
@changelog_1242_li
@changelog_1250_li
SQL statements in the exception message are no longer included if they contain '--hide--'.
@changelog_1243_li
@changelog_1251_li
Temporary local tables did not always work after reconnect if AUTO_SERVER=TRUE
@changelog_1244_li
@changelog_1252_li
New system property h2.defaultMaxLengthInplaceLob to change the default maximum size of an in-place LOB object.
@changelog_1245_li
@changelog_1253_li
New system property h2.nullConcatIsNull to change the default null concatenation behavior. The default will be enabled in version 1.2.
@changelog_1246_li
@changelog_1254_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_1247_li
@changelog_1255_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_1248_li
@changelog_1256_li
ChangeFileEncryption did not work with Lob subdirectories. Fixed.
@changelog_1249_li
@changelog_1257_li
Issue 121: JaQu: new simple update and merge methods.
@changelog_1250_li
@changelog_1258_li
Issue 120: JaQu didn't close result sets.
@changelog_1251_li
@changelog_1259_li
Issue 119: JaQu creates wrong WHERE conditions on some inputs.
@changelog_1252_li
@changelog_1260_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_1253_li
@changelog_1261_li
SELECT COUNT(*) FROM SYSTEM_RANGE(...) returned the wrong result. Fixed.
@changelog_1254_li
@changelog_1262_li
The Recover tool now also processes the log files, however applying those changes is still a manual process.
@changelog_1255_li
@changelog_1263_li
New sample application that shows how to pass data to a trigger.
@changelog_1256_li
@changelog_1264_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_1257_li
@changelog_1265_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_1258_li
@changelog_1266_li
Updating many rows with the same CLOB or BLOB values could result in FileNotFoundException.
@changelog_1259_li
@changelog_1267_li
Statement.getConnection() threw an exception if the connection was already closed.
@changelog_1260_li
@changelog_1268_li
The native fulltext index kept a reference to a database after the database was closed.
@changelog_1261_li
@changelog_1269_li
Non-unique in-memory hash indexes are now supported. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1262_li
@changelog_1270_li
The optimizer does a better job for joins if indexes are missing.
@changelog_1263_h2
@changelog_1271_h2
Version 1.1.118 (2009-09-04)
@changelog_1264_li
@changelog_1272_li
SHOW COLUMNS only listed indexed columns.
@changelog_1265_li
@changelog_1273_li
When calling SHUTDOWN IMMEDIATELY in the server mode, the .trace.db file was not closed.
@changelog_1266_li
@changelog_1274_li
DatabaseMetaData.getPrimaryKeys: the wrong constraint name was reported if there was another constraint on the same table and columns.
@changelog_1267_li
@changelog_1275_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_1268_li
@changelog_1276_li
Native fulltext search: before searching, FT_INIT() had to be called. This is no longer required.
@changelog_1269_li
@changelog_1277_li
Better support GaeVFS (Google App Engine Virtual File System).
@changelog_1270_li
@changelog_1278_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_1271_li
@changelog_1279_li
Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1272_li
@changelog_1280_li
PreparedStatement.setObject now converts a java.lang.Character to a string.
@changelog_1273_li
@changelog_1281_li
H2 Console: PierPaolo Ucchino has completed the Italian translation. Thanks a lot!
@changelog_1274_li
@changelog_1282_li
Various tools now use Java 5 var-args, such as main the methods and SimpleResultSet.addRow.
@changelog_1275_li
@changelog_1283_li
H2 Console: indexes of tables of non-default schemas are now also listed.
@changelog_1276_li
@changelog_1284_li
Issue 111: Multi-version concurrency / duplicate primary key after rollback.
@changelog_1277_li
@changelog_1285_li
Issue 110: Multi-version concurrency / wrong exception is thrown.
@changelog_1278_li
@changelog_1286_li
Parser: sequenceName.NEXTVAL and CURRVAL did not respect the schema search path.
@changelog_1279_li
@changelog_1287_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_1280_li
@changelog_1288_li
The stack trace of very common exceptions is no longer written to the .trace.db file by default.
@changelog_1281_li
@changelog_1289_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_1282_li
@changelog_1290_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_1283_h2
@changelog_1291_h2
Version 1.1.117 (2009-08-09)
@changelog_1284_li
@changelog_1292_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_1285_li
@changelog_1293_li
JaQu: the order of the fields in the database no longer needs to match the order in the database.
@changelog_1286_li
@changelog_1294_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_1287_li
@changelog_1295_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_1288_li
@changelog_1296_li
Views using functions were not re-evaluated when necessary.
@changelog_1289_li
@changelog_1297_li
Improved MySQL compatibility for SHOW COLUMNS.
@changelog_1290_li
@changelog_1298_li
Improved PostgreSQL compatibility for timestamp literals with timezone.
@changelog_1291_li
@changelog_1299_li
Sergi Vladykin translated the error messages to Russian. Thanks a lot!
@changelog_1292_li
@changelog_1300_li
Support for Java 6 DatabaseMetaData.getTables, getColumns, getProcedures, and getProcedureColumns.
@changelog_1293_li
@changelog_1301_li
Issue 101: Rollback of a large transaction (more than 100000 rows) could fail.
@changelog_1294_li
@changelog_1302_li
Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1295_li
@changelog_1303_li
The functions LENGTH, OCTET_LENGTH, and BIT_LENGTH now return BIGINT.
@changelog_1296_li
@changelog_1304_li
Data types CLOB and BLOB: the maximum precision was Integer.MAX_VALUE, it is now Long.MAX_VALUE.
@changelog_1297_li
@changelog_1305_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_1298_li
@changelog_1306_li
Parsing SQL script files is now faster.
@changelog_1299_li
@changelog_1307_li
CSV reading is now faster.
@changelog_1300_li
@changelog_1308_li
SimpleResultSet.newInstance(SimpleRowSource rs) did not work.
@changelog_1301_h2
@changelog_1309_h2
Version 1.1.116 (2009-07-18)
@changelog_1302_li
@changelog_1310_li
Server-less multi-connection mode: more bugs are fixed.
@changelog_1303_li
@changelog_1311_li
The built-in help (INFORMATION_SCHEMA.HELP) is smaller, shrinking the jar file size a bit.
@changelog_1304_li
@changelog_1312_li
H2 Console: column of tables of non-default schemas are now also listed, except for schemas starting with 'INFO'.
@changelog_1305_li
@changelog_1313_li
ALTER TABLE: removing an auto-increment or identity column didn't remove the sequence.
@changelog_1306_li
@changelog_1314_li
Creating indexes is now a bit faster.
@changelog_1307_li
@changelog_1315_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_1308_li
@changelog_1316_li
PG Server: improved compatibility by using the type ids of the PostgreSQL driver. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1309_li
@changelog_1317_li
H2 Console: Oracle system tables are no longer listed, improving performance.
@changelog_1310_li
@changelog_1318_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_1311_li
@changelog_1319_li
New system property h2.defaultResultSetConcurrency to change the default result set concurrency.
@changelog_1312_li
@changelog_1320_li
JDBC: using an invalid result set type or concurrency now throws an exception.
@changelog_1313_li
@changelog_1321_li
If a pooled connection was not closed but garbage collected, a NullPointerException could occur.
@changelog_1314_li
@changelog_1322_li
Fulltext search: a NullPointerException was thrown when updating a value that was NULL previously.
@changelog_1315_li
@changelog_1323_li
The Recover tool did not work with .data.db files of the wrong size.
@changelog_1316_li
@changelog_1324_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_1317_li
@changelog_1325_li
The soft-references cache (CACHE_TYPE=SOFT_LRU) could throw a NullPointerException.
@changelog_1318_li
@changelog_1326_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_1319_h2
@changelog_1327_h2
Version 1.1.115 (2009-06-21)
@changelog_1320_li
@changelog_1328_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_1321_li
@changelog_1329_li
ALTER TABLE could throw an exception "object already exists" in some cases.
@changelog_1322_li
@changelog_1330_li
Views: in some situations, an ArrayIndexOutOfBoundsException was thrown when using the same view concurrently.
@changelog_1323_li
@changelog_1331_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_1324_li
@changelog_1332_li
H2 Console: the language was reset to the browser language when disconnecting.
@changelog_1325_li
@changelog_1333_li
H2 Console: improved Polish translation.
@changelog_1326_li
@changelog_1334_li
Server-less multi-connection mode: more bugs are fixed.
@changelog_1327_li
@changelog_1335_li
The download page now included the SHA1 checksums.
@changelog_1328_li
@changelog_1336_li
Shell tool: the file encoding workaround is now documented if you run java org.h2.tools.Shell -?.
@changelog_1329_li
@changelog_1337_li
The RunScript tool and SQL statement did not work with the compression method LZF.
@changelog_1330_li
@changelog_1338_li
Fulltext search: searching for NULL or an empty string threw an exception.
@changelog_1331_li
@changelog_1339_li
Lucene fulltext search: FTL_DROP_ALL did not drop the triggers.
@changelog_1332_li
@changelog_1340_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_1333_li
@changelog_1341_li
Data types: LONG is now an alias for BIGINT.
@changelog_1334_h2
@changelog_1342_h2
Version 1.1.114 (2009-06-01)
@changelog_1335_li
@changelog_1343_li
ResultSetMetaData.getColumnClassName returned the wrong class for CLOB and BLOB columns.
@changelog_1336_li
@changelog_1344_li
Fulltext search: data is no longer deleted and re-inserted if the indexed columns didn't change.
@changelog_1337_li
@changelog_1345_li
In some situations, an ArrayIndexOutOfBoundsException was thrown when adding rows. This was caused by a bug in the b-tree code.
@changelog_1338_li
@changelog_1346_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_1339_li
@changelog_1347_li
The Recover tool did not always work when the database contains referential integrity constraints.
@changelog_1340_li
@changelog_1348_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/).
@cheatSheet_1000_h1
...
...
@@ -2672,177 +2696,180 @@ Are there Known Bugs? When is the Next Release?
Usually, bugs get fixes as they are found. There is a release every few weeks. Here is the list of known and confirmed issues:
@faq_1019_li
Tomcat and Glassfish 3 set most static fields (final or non-final) to <code>null</code> when unloading a web application. This can cause a <code>NullPointerException</code> in H2 versions 1.1.107 and older, and may still not work in newer versions. Please report it if you run into this issue. In Tomcat >= 6.0 this behavior can be disabled by setting the system property <code>org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false</code>, however Tomcat may then run out of memory. A known workaround is to put the <code>h2*.jar</code> file in a shared <code>lib</code> directory (<code>common/lib</code>).
Apache Harmony: there seems to be a bug in Harmony that affects H2. See <a href="https://issues.apache.org/jira/browse/HARMONY-6505">HARMONY-6505</a>.
@faq_1020_li
Some problems have been found with right outer join. Internally, it is converted to left outer join, which does not always produce the same results as other databases when used in combination with other joins.
Tomcat and Glassfish 3 set most static fields (final or non-final) to <code>null</code> when unloading a web application. This can cause a <code>NullPointerException</code> in H2 versions 1.1.107 and older, and may still not work in newer versions. Please report it if you run into this issue. In Tomcat >= 6.0 this behavior can be disabled by setting the system property <code>org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false</code>, however Tomcat may then run out of memory. A known workaround is to put the <code>h2*.jar</code> file in a shared <code>lib</code> directory (<code>common/lib</code>).
@faq_1021_li
Some problems have been found with right outer join. Internally, it is converted to left outer join, which does not always produce the same results as other databases when used in combination with other joins.
@faq_1022_li
When using Install4j before 4.1.4 on Linux and enabling <code>pack200</code>, the <code>h2*.jar</code> becomes corrupted by the install process, causing application failure. A workaround is to add an empty file <code>h2*.jar.nopack</code> next to the <code>h2*.jar</code> file. This problem is solved in Install4j 4.1.4.
@faq_1022_p
@faq_1023_p
For a complete list, see <a href="http://code.google.com/p/h2database/issues/list">Open Issues</a>.
@faq_1023_h3
@faq_1024_h3
Is this Database Engine Open Source?
@faq_1024_p
@faq_1025_p
Yes. It is free to use and distribute, and the source code is included. See also under license.
@faq_1025_h3
@faq_1026_h3
My Query is Slow
@faq_1026_p
@faq_1027_p
Slow <code>SELECT</code> (or <code>DELETE, UPDATE, MERGE</code>) statement can have multiple reasons. Follow this checklist:
@faq_1027_li
@faq_1028_li
Run <code>ANALYZE</code> (see documentation for details).
@faq_1028_li
@faq_1029_li
Run the query with <code>EXPLAIN</code> and check if indexes are used (see documentation for details).
@faq_1029_li
@faq_1030_li
If required, create additional indexes and try again using <code>ANALYZE</code> and <code>EXPLAIN</code>.
@faq_1030_li
@faq_1031_li
If it doesn't help please report the problem.
@faq_1031_h3
@faq_1032_h3
How to Create a New Database?
@faq_1032_p
@faq_1033_p
By default, a new database is automatically created if it does not yet exist. See <a href="tutorial.html#creating_new_databases">Creating New Databases</a>.
@faq_1033_h3
@faq_1034_h3
How to Connect to a Database?
@faq_1034_p
@faq_1035_p
The database driver is <code>org.h2.Driver</code>, and the database URL starts with <code>jdbc:h2:</code>. To connect to a database using JDBC, use the following code:
@faq_1035_h3
@faq_1036_h3
Where are the Database Files Stored?
@faq_1036_p
@faq_1037_p
When using database URLs like <code>jdbc:h2:~/test</code>, the database is stored in the user directory. For Windows, this is usually <code>C:\Documents and Settings\<userName></code>. If the base directory is not set (as in <code>jdbc:h2:test</code>), the database files are stored in the directory where the application is started (the current working directory). When using the H2 Console application from the start menu, this is <code><Installation Directory>/bin</code>. The base directory can be set in the database URL. A fixed or relative path can be used. When using the URL <code>jdbc:h2:file:data/sample</code>, the database is stored in the directory <code>data</code> (relative to the current working directory). The directory is created automatically if it does not yet exist. It is also possible to use the fully qualified directory name (and for Windows, drive name). Example: <code>jdbc:h2:file:C:/data/test</code>
@faq_1037_h3
@faq_1038_h3
What is the Size Limit (Maximum Size) of a Database?
@faq_1038_p
@faq_1039_p
See <a href="advanced.html#limits_limitations">Limits and Limitations</a>.
@faq_1039_h3
@faq_1040_h3
Is it Reliable?
@faq_1040_p
@faq_1041_p
That is not easy to say. It is still a quite new product. A lot of tests have been written, and the code coverage of these tests is very high. Randomized stress tests are run regularly. But there are probably still bugs that have not yet been found (as with most software). Some features are known to be dangerous, they are only supported for situations where performance is more important than reliability. Those dangerous features are:
@faq_1041_li
@faq_1042_li
Using the transaction isolation level <code>READ_UNCOMMITTED</code> (<code>LOCK_MODE 0</code>) while at the same time using multiple connections.
@faq_1042_li
@faq_1043_li
Disabling database file protection using <code>FILE_LOCK=NO</code> in the database URL.
@faq_1043_li
@faq_1044_li
Disabling referential integrity using <code>SET REFERENTIAL_INTEGRITY FALSE</code>.
@faq_1044_p
@faq_1045_p
In addition to that, running out of memory should be avoided. In older versions, OutOfMemory errors while using the database could corrupt a databases.
@faq_1045_p
@faq_1046_p
Some areas of this database are not fully tested. When using one of those features for production, please ensure your use case is well tested (if possible with automated test cases). Those areas are:
@faq_1046_li
@faq_1047_li
Platforms other than Windows XP, Linux, Mac OS X, or JVMs other than Sun 1.5 or 1.6
@faq_1047_li
@faq_1048_li
The features <code>AUTO_SERVER</code> and <code>AUTO_RECONNECT</code>
@faq_1048_li
@faq_1049_li
The file locking method 'Serialized'
@faq_1049_li
@faq_1050_li
The MVCC (multi version concurrency) mode
@faq_1050_li
@faq_1051_li
Cluster mode, 2-phase commit, savepoints
@faq_1051_li
@faq_1052_li
24/7 operation
@faq_1052_li
@faq_1053_li
Some operations on databases larger than 500 MB may be slower than expected
@faq_1053_li
@faq_1054_li
The optimizer may not always select the best plan
@faq_1054_li
@faq_1055_li
Fulltext search
@faq_1055_li
@faq_1056_li
Operations on LOBs over 2 GB
@faq_1056_p
@faq_1057_p
Areas considered experimental are:
@faq_1057_li
@faq_1058_li
The PostgreSQL server
@faq_1058_li
@faq_1059_li
Multi-threading within the engine using <code>SET MULTI_THREADED=1</code>
@faq_1059_li
@faq_1060_li
Compatibility modes for other databases (only some features are implemented)
@faq_1060_li
@faq_1061_li
The soft reference cache (CACHE_TYPE=SOFT_LRU). It might not improve performance, and out of memory issues have been reported.
@faq_1061_p
@faq_1062_p
Some users have reported that after a power failure, the database cannot be opened sometimes. In this case, use a backup of the database or the Recover tool. Please report such problems. The plan is that the database automatically recovers in all situations.
@faq_1062_h3
@faq_1063_h3
Column Names are Incorrect?
@faq_1063_p
@faq_1064_p
For the query <code>SELECT ID AS X FROM TEST</code> the method <code>ResultSetMetaData.getColumnName()</code> returns <code>ID</code>, I expect it to return <code>X</code>. What's wrong?
@faq_1064_p
@faq_1065_p
This is not a bug. According the the JDBC specification, the method <code>ResultSetMetaData.getColumnName()</code> should return the name of the column and not the alias name. If you need the alias name, use <a href="http://java.sun.com/javase/6/docs/api/java/sql/ResultSetMetaData.html#getColumnLabel(int)"><code>ResultSetMetaData.getColumnLabel()</code></a>. Other database don't work like this (they don't follow the JDBC specification). If you need compatibility with those databases, use the <a href="features.html#compatibility">Compatibility Mode</a>, or set the system property <a href="../javadoc/org/h2/constant/SysProperties.html#h2.aliasColumnName"><code>h2.aliasColumnName</code></a>.
@faq_1065_p
@faq_1066_p
This also applies to DatabaseMetaData calls that return a result set. The columns in the JDBC API are column labels, not column names.
@faq_1066_h3
@faq_1067_h3
Float is Double?
@faq_1067_p
@faq_1068_p
For a table defined as <code>CREATE TABLE TEST(X FLOAT)</code> the method <code>ResultSet.getObject()</code> returns a <code>java.lang.Double</code>, I expect it to return a <code>java.lang.Float</code>. What's wrong?
@faq_1068_p
@faq_1069_p
This is not a bug. According the the JDBC specification, the JDBC data type <code>FLOAT</code> is equivalent to <code>DOUBLE</code>, and both are mapped to <code>java.lang.Double</code>. See also <a href="http://java.sun.com/j2se/1.5.0/docs/guide/jdbc/getstart/mapping.html#1055162"> Mapping SQL and Java Types - 8.3.10 FLOAT</a>.
@faq_1069_h3
@faq_1070_h3
Why is Opening my Database Slow?
@faq_1070_p
@faq_1071_p
To find out what the problem is, use the H2 Console and click on "Test Connection" instead of "Login". After the "Login Successful" appears, click on it (it's a link). This will list the top stack traces. Then either analyze this yourself, or post those stack traces in the Google Group.
@faq_1071_p
@faq_1072_p
To find out what the problem is, open the database in embedded mode using the H2 Console. This will print progress information. If you have many lines with 'Creating index' it is an indication that the database was not closed the last time.
@faq_1072_p
@faq_1073_p
Other possible reasons are: the database is very big (many GB), or contains linked tables that are slow to open.
@faq_1073_h3
@faq_1074_h3
Is the GCJ Version Stable? Faster?
@faq_1074_p
@faq_1075_p
The GCJ version is not as stable as the Java version. When running the regression test with the GCJ version, sometimes the application just stops at what seems to be a random point without error message. Currently, the GCJ version is also slower than when using the Sun VM. However, the startup of the GCJ version is faster than when using a VM.
@faq_1075_h3
@faq_1076_h3
How to Translate this Project?
@faq_1076_p
@faq_1077_p
For more information, see <a href="build.html#translating">Build/Translating</a>.
@features_1000_h1
...
...
@@ -9517,16 +9544,19 @@ Support a data type "timestamp with timezone" using java.util.Calendar.
@roadmap_1448_li
Maybe use a different page layout: keep the data at the head of the page, and ignore the tail (don't store / read it). This may increase write / read performance depending on the file system.
@roadmap_1449_h2
@roadmap_1449_li
Indexes of temporary tables are currently kept in-memory. Is this how it should be?
@roadmap_1450_h2
Not Planned
@roadmap_1450_li
@roadmap_1451_li
HSQLDB (did) support this: select id i from test where i<0 (other databases don't). Supporting it may break compatibility.
@roadmap_1451_li
@roadmap_1452_li
String.intern (so that Strings can be compared with ==) will not be used because some VMs have problems when used extensively.
@roadmap_1452_li
@roadmap_1453_li
In prepared statements, identifier names (table names and so on) can not be parameterized. Adding such a feature would complicate the source code without providing reasonable speedup, and would slow down regular prepared statements.
@sourceError_1000_h1
...
...
@@ -9980,7 +10010,7 @@ Stopping a TCP Server from Another Process
Using Hibernate
@tutorial_1137_p
This database supports Hibernate version 3.1 and newer. You can use the HSQLDB Dialect, or the native H2 Dialect. Unfortunately the H2 Dialect included in Hibernate is buggy. A <a href="http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401">patch for Hibernate</a> has been submitted. The dialect for the newest version of Hibernate is also available at <code>src/tools/org/hibernate/dialect/H2Dialect.java.txt</code>. You can rename it to <code>H2Dialect.java</code> and include this as a patch in your application.
This database supports Hibernate version 3.1 and newer. You can use the HSQLDB Dialect, or the native H2 Dialect. Unfortunately the H2 Dialect included in some versions of Hibernate is buggy. A <a href="http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401">patch for Hibernate</a> has been submitted and is now applied. The dialect for the newest version of Hibernate is also available at <code>src/tools/org/hibernate/dialect/H2Dialect.java.txt</code>. You can rename it to <code>H2Dialect.java</code> and include this as a patch in your application, or upgrade to a version of Hibernate where this is fixed.
# There is a list of keywords that can't be used as identifiers (table names, column names and so on), unless they are quoted (surrounded with double quotes). The list is currently:
@advanced_1120_code
# CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT, EXISTS, FALSE, FOR, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, WHERE
# CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT, EXISTS, FALSE, FOR, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, UNIQUE, WHERE
@advanced_1121_p
# Certain words of this list are keywords because they are functions that can be used without '()' for compatibility, for example <code>CURRENT_TIMESTAMP</code>.
...
...
@@ -1399,1021 +1399,1045 @@ Centralリポジトリの利用
@changelog_1001_h2
#Next Version (unreleased)
@changelog_1002_h2
#Version 1.2.134 (2010-04-23)
@changelog_1002_li
#Global temporary tables are now deleted when closing the database. Before, they were deleted when opening the database the next time.
@changelog_1003_li
#New system property h2.analyzeAuto (default 0 meaning disabled) to automatically run ANALYZE after that many changes to a table. For details, see the Javadoc of this system property. The plan is to set this property to 2000 in version 1.3.x.
#UNIQUE was not listed as a keyword.
@changelog_1004_li
#JdbcXAConnection.start() does not support TMJOIN. Issue 189.
#Improved error message when an non-SQL-exception occurred in a user defined function. The method name and parameters are included in the error message.
@changelog_1005_li
#MySQL compatibility: TIMESTAMPDIFF is now an alias for DATEDIFF.
#For some queries, the exception did not include the SQL statement. Example: select x from system_range(1, 2) group by 'a'.
@changelog_1006_li
#MERGE did not respect foreign key and check constraints.
#The Shell tool will execute SQL statements passed as using the command line parameter -sql.
@changelog_1007_li
#ALTER TABLE ALTER COLUMN: changing the data type of a column no longer makes it nullable.
#If InetAddress.getLocalHost() fails, the database should now throw an exception.
@changelog_1008_li
#When using AUTO_SERVER=TRUE, the server is now started as a daemon thread. This was a problem when using Tomcat and a connection pool.
#New columns INFORMATION_SCHEMA.INDEXES.INDEX_CLASS and INFORMATION_SCHEMA.TABLES.TABLE_CLASS.
@changelog_1009_li
#INFORMATION_SCHEMA.INDEXES.SQL now contains the CREATE INDEX statement instead of just the fully qualified index name.
@changelog_1010_h2
#Version 1.2.134 (2010-04-23)
@changelog_1011_li
#New system property h2.analyzeAuto (default 0 meaning disabled) to automatically run ANALYZE after that many changes to a table. For details, see the Javadoc of this system property. The plan is to set this property to 2000 in version 1.3.x.
@changelog_1012_li
#JdbcXAConnection.start() does not support TMJOIN. Issue 189.
@changelog_1013_li
#MySQL compatibility: TIMESTAMPDIFF is now an alias for DATEDIFF.
@changelog_1014_li
#MERGE did not respect foreign key and check constraints.
@changelog_1015_li
#ALTER TABLE ALTER COLUMN: changing the data type of a column no longer makes it nullable.
@changelog_1016_li
#When using AUTO_SERVER=TRUE, the server is now started as a daemon thread. This was a problem when using Tomcat and a connection pool.
@changelog_1017_li
#Servers can now be started as a daemon thread using the command line options -tcpDaemon, -pgDaemon, and -webDaemon.
@changelog_1010_li
@changelog_1018_li
#H2 Console: the built-in commands are now documented.
@changelog_1011_li
@changelog_1019_li
#REPLACE: if any parameter is null, the result is null.
@changelog_1012_li
@changelog_1020_li
#Queries with DISTINCT and ORDER BY will now use the index on ORDER BY if possible. This is specially important for queries used inside IN(SELECT ...).
@changelog_1013_li
@changelog_1021_li
#The new statement EXPLAIN ANALYZE executes the statement, and displays the query plan with the actual row scan count for each table.
@changelog_1014_li
@changelog_1022_li
#H2 Console: the auto-complete feature didn't quote column names that need quoting. Issue 186.
@changelog_1015_li
@changelog_1023_li
#The experimental LOB storage mechanism now supports all features of the old one. To use it, set the system property "h2.lobInDatabase" to "true". If you have used this feature in version 1.2.133, you need to export and re-import the database using SCRIPT / RUNSCRIPT.
@changelog_1016_li
@changelog_1024_li
#The functions isBeforeFirst() and isAfterLast() were not compliant to the JDBC spec. If the ResultSet contains no rows, they must return false. Fixed.
@changelog_1017_li
@changelog_1025_li
#Filesystem parameters like "split:" didn't work in server mode with baseDir set.
@changelog_1018_li
@changelog_1026_li
#If baseDir is set, and a database name is given which points to a directory outside the baseDir (eg. "../dbname"), an exception is thrown.
@changelog_1019_h2
@changelog_1027_h2
#Version 1.2.133 (2010-04-10)
@changelog_1020_li
@changelog_1028_li
#A new experimental LOB storage mechanism is available. When enabled, CLOB and BLOB data is stored in hidden tables in the database. To use it, set the system property "h2.lobInDatabase" to "true". Compression is not yet implemented. Duplicate objects are only stored once. Usually writing is slower, but reading is faster (mainly because of caching).
@changelog_1021_li
@changelog_1029_li
#The Shell tool threw a NumberFormatException on a empty statement.
@changelog_1022_li
@changelog_1030_li
#The h2small-*.jar did not support "drop all objects delete files". Now it is supported (the DeleteDbFiles tool is now included).
@changelog_1023_li
@changelog_1031_li
#Operations that don't fit in memory are now faster. Temporary file handling was changed.
@changelog_1024_li
@changelog_1032_li
#The default maximum log stream size is now 2 MB. This is a good value according to some performance tests.
@changelog_1025_li
@changelog_1033_li
#New system property "h2.syncMethod" to configure what method to call when closing the database, on checkpoint, and on CHECKPOINT SYNC. The default is "sync" which calls RandomAccessFile.getFD().sync().
@changelog_1026_li
@changelog_1034_li
#ROWNUM could not be used for pagination. The follow query returned no rows: select x from (select *, rownum as r from system_range(1, 3)) where r=2;
@changelog_1027_li
@changelog_1035_li
#Workaround for a java.sql.Date issue: years above 9999 are not formatted correctly. When calling ResultSet.getString() on a date value, an alternative formatting algorithm is used.
@changelog_1028_li
@changelog_1036_li
#Prepared statements with nested subqueries did not always return the correct result. Example: select ?, ?, (select count(*) from test t, (select id from test where 0=?) t2 where t2.id=t.id) from test
@changelog_1029_li
@changelog_1037_li
#When using MULTI_THREADED=TRUE, the exception following exception could be thrown: "object already exists: TABLES"
@changelog_1030_li
@changelog_1038_li
#Comparison of integer columns against float numbers was not always correct. Issue 182.
@changelog_1031_li
@changelog_1039_li
#H2 Console: Editing the result of a multi-line queries failed. Issue 183.
@changelog_1032_li
@changelog_1040_li
#H2 Console: if the settings file (.h2.properties) can't be accessed, the exception is now ignored.
@changelog_1033_h2
@changelog_1041_h2
#Version 1.2.132 (2010-03-21)
@changelog_1034_li
@changelog_1042_li
#The implementation of a Java to C (source code level) converter has been started. The plan is: it should be possible to convert H2 (or a part of it) to C so that the database can be run without a JVM. This will be a long term project (it may take a year or so).
@changelog_1035_li
@changelog_1043_li
#User defined table implementation can now be used using CREATE TABLE ... ENGINE. Thanks to Sergi Vladykin for implementing this feature!
@changelog_1036_li
@changelog_1044_li
#Improved MS SQL Server compatibility: support string concatenation using "+". Thanks to Stepan for the patch!
@changelog_1037_li
@changelog_1045_li
#When using the multi-threaded mode, running ANALYZE concurrently in multiple connections could throw an exception.
@changelog_1038_li
@changelog_1046_li
#The MERGE statement is now about 30% faster when using a PreparedStatement.
@changelog_1039_li
@changelog_1047_li
#Multi-column indexes where the second or later column was descending did not always produce correct results (rows were missing in the result set, or the result set was empty).
@changelog_1040_li
@changelog_1048_li
#When using large transactions or a small log size, the database could get very slow (profiling shows the hotspot is in FileObjectDisk.sync()).
@changelog_1041_li
@changelog_1049_li
#The Shell tool now prints the stack trace when the list mode is enabled.
@changelog_1042_li
@changelog_1050_li
#CREATE ALIAS ... AS: Compilation was incorrect if the source code contained characters that are not supported by the default file encoding.
@changelog_1043_li
@changelog_1051_li
#Issue 176: the JdbcDataSource now also supports a 'description' property.
@changelog_1044_li
@changelog_1052_li
#The Shell tool threw a ArrayIndexOutOfBoundsException after 20 statements.
@changelog_1045_li
@changelog_1053_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_1046_li
@changelog_1054_li
#Literals of type BIGINT now have the correct data type.
@changelog_1047_h2
@changelog_1055_h2
#Version 1.2.131 (2010-03-05)
@changelog_1048_li
@changelog_1056_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_1049_li
@changelog_1057_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_1050_li
@changelog_1058_li
#After the database was closed, a null pointer exception could occur in Database.flush.
@changelog_1051_li
@changelog_1059_li
#An ArrayIndexOutOfBoundsException could occur in the page store (eg. on "delete from table"). Fixed.
@changelog_1052_h2
@changelog_1060_h2
#Version 1.2.130 (2010-02-26)
@changelog_1053_li
@changelog_1061_li
#EXPLAIN: The query plan now contains ".tableScan" if a table scan is used.
@changelog_1054_li
@changelog_1062_li
#IN(..): when combining and IN(..) condition with a condition that didn't use an index, the result could contain duplicate rows.
@changelog_1055_li
@changelog_1063_li
#IN(..): the index was not used if there were multiple IN(..) conditions.
@changelog_1056_li
@changelog_1064_li
#For foreign key constraints, the metadata column INFORMATION_SCHEMA.INDEXES.CONSTRAINT_NAME was not set for non-unique indexes.
@changelog_1057_li
@changelog_1065_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_1058_li
@changelog_1066_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_1059_li
@changelog_1067_li
#When using temporary tables, the database didn't shrink sometimes when closing. Also, sometimes a database could not recover normally.
@changelog_1060_li
@changelog_1068_li
#Large transactions could run out of heap space. The maximum size of a transaction is now much larger.
@changelog_1061_li
@changelog_1069_li
#The default setting for the system property h2.webMaxValueLength is now 100000 (it was 10000 before).
@changelog_1062_li
@changelog_1070_li
#Creating a database was delayed about 2 seconds if the directory didn't exist.
@changelog_1063_li
@changelog_1071_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_1064_h2
@changelog_1072_h2
#Version 1.2.129 (2010-02-19)
@changelog_1065_li
@changelog_1073_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_1066_li
@changelog_1074_li
#CREATE ALIAS: error message when compiling Java code have been improved.
@changelog_1067_li
@changelog_1075_li
#MVCC: creating a table with an incorrect constraint could cause strange errors.
@changelog_1068_li
@changelog_1076_li
#Hash indexes now are only used for single column indexes.
@changelog_1069_li
@changelog_1077_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_1070_li
@changelog_1078_li
#The file system abstraction no longer throws SQL exceptions.
@changelog_1071_li
@changelog_1079_li
#DatabaseEventListener.diskSpaceIsLow has changed.
@changelog_1072_li
@changelog_1080_li
#The CompressTool no longer throw as SQL exceptions. Instead, it throws runtime exceptions.
@changelog_1073_li
@changelog_1081_li
#SimpleResultSet.addColumn and addRow now can throw a IllegalStateException instead of a SQLException.
@changelog_1074_li
@changelog_1082_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_1075_li
@changelog_1083_li
#The BNF parser now uses the visitor pattern.
@changelog_1076_li
@changelog_1084_li
#Converting a UUID to bytes was incorrect. Because of that, updatable result sets on tables with UUID primary key did not work.
@changelog_1077_li
@changelog_1085_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_1078_li
@changelog_1086_li
#H2 Console: asynchronous login (using a DatabaseEventListener) is no longer supported.
@changelog_1079_li
@changelog_1087_li
#A workaround for a Windows socket problem has been implemented. Thanks a lot to Sergi Vladykin.
@changelog_1080_li
@changelog_1088_li
#The Recover tool did not convert correctly convert CLOB data with non-ASCII characters.
@changelog_1081_li
@changelog_1089_li
#Tools: the method run(String... args) has been renamed to runTool(String... args).
@changelog_1082_li
@changelog_1090_li
#Server.startWebServer(Connection) was not working as expected.
@changelog_1083_li
@changelog_1091_li
#The database URL option ACCESS_MODE_LOG is no longer supported.
@changelog_1084_li
@changelog_1092_li
#The database URL option RECOVER has currently no effect.
@changelog_1085_li
@changelog_1093_li
#Converting an old (non-page store) database is no longer supported using this version.
@changelog_1086_li
@changelog_1094_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_1087_li
@changelog_1095_li
#The setting LOG has currently no effect (it only had an effect when the page store was disabled).
@changelog_1088_li
@changelog_1096_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_1089_li
@changelog_1097_li
#The translated resources are now stored in UTF-8 format.
@changelog_1090_li
@changelog_1098_li
#The Windows service wrapper now detects if multiple versions of H2 are installed.
@changelog_1091_h2
@changelog_1099_h2
#Version 1.2.128 (2010-01-30)
@changelog_1092_li
@changelog_1100_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_1093_li
@changelog_1101_li
#The DeleteDbFiles tool deleted all files in the .lob.db directory, even files that didn't belong to the database.
@changelog_1094_li
@changelog_1102_li
#Automatic conversion of old databases to the page store format failed if the database contained LOB files.
@changelog_1095_li
@changelog_1103_li
#Nested subqueries didn't work for INSERT INTO and IN(..). Example: insert into test ((select 1));
@changelog_1096_li
@changelog_1104_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_1097_li
@changelog_1105_li
#Less classes are loaded when using the database in embedded mode.
@changelog_1098_li
@changelog_1106_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_1099_li
@changelog_1107_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_1100_li
@changelog_1108_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_1101_li
@changelog_1109_li
#Improved PostgreSQL compatibility (support SHOW DEFAULT_TRANSACTION_ISOLATION).
@changelog_1102_li
@changelog_1110_li
#Documentation: the javadocs for Csv.write and read used the wrong default charset.
@changelog_1103_li
@changelog_1111_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_1104_li
@changelog_1112_li
#If a FOR UPDATE query was executed twice (using a PreparedStatement), the table was not locked.
@changelog_1105_li
@changelog_1113_li
#Triggers: INSTEAD OF triggers are now supported. Such triggers can be defined on views.
@changelog_1106_li
@changelog_1114_li
#New system property h2.identifiersToUpper. If set to false, identifiers in SQL statements are case sensitive even if they are not quoted.
@changelog_1107_li
@changelog_1115_li
#Slightly improved performance if the table is already locked.
@changelog_1108_li
@changelog_1116_li
#CompressLZF: faster decompression.
@changelog_1109_li
@changelog_1117_li
#PgServer: the wrong size was sent for VARCHAR data. Thanks again to Sergi Vladykin for the patch.
@changelog_1110_li
@changelog_1118_li
#Serialized access mode (server-less multi-connection mode): fixed getGeneratedKeys() for sequences.
@changelog_1111_h2
@changelog_1119_h2
#Version 1.2.127 (2010-01-15)
@changelog_1112_li
@changelog_1120_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_1113_li
@changelog_1121_li
#Page store: new databases can not be opened with older versions.
@changelog_1114_li
@changelog_1122_li
#Page store: adding data to new database is now faster.
@changelog_1115_li
@changelog_1123_li
#File system: getting the file name from a path is now faster. This should speed up BLOB and CLOB access.
@changelog_1116_li
@changelog_1124_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_1117_li
@changelog_1125_li
#SHOW COLUMNS did not work correctly if there where multiple indexes on the same columns.
@changelog_1118_li
@changelog_1126_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_1119_li
@changelog_1127_li
#Result sets larger than 2 GB threw an exception "Negative seek offset". Fixed.
@changelog_1120_li
@changelog_1128_li
#If the system property h2.check was set to false, an ArrayIndexOutOfBoundsException could occur.
@changelog_1121_li
@changelog_1129_li
#Alter table is now supported even if a table has views defined.
@changelog_1122_li
@changelog_1130_li
#Fulltext search: exceptions within the fulltext search package had the wrong SQL state.
@changelog_1123_li
@changelog_1131_li
#The Lucene fulltext search ignored transaction rollback. Fixed using a trigger on rollback.
@changelog_1124_li
@changelog_1132_li
#Trigger can now be called on rollback.
@changelog_1125_li
@changelog_1133_li
#The shell script h2.sh ignored command line line arguments.
@changelog_1126_li
@changelog_1134_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_1127_li
@changelog_1135_li
#The user home directory prefix (~) is now only expanded when followed by a slash or backslash, or standing alone.
@changelog_1128_li
@changelog_1136_li
#Native fulltext search: before inserting or deleting data, FT_INIT() had to be called. This is no longer required.
@changelog_1129_li
@changelog_1137_li
#The .trace.db file is now only created if required.
@changelog_1130_li
@changelog_1138_li
#Shell tool: improved PostgreSQL compatibility.
@changelog_1131_li
@changelog_1139_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_1132_li
@changelog_1140_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_1133_li
@changelog_1141_li
#Faster data conversion from BIGINT or INT to DECIMAL.
@changelog_1134_li
@changelog_1142_li
#Server-less multi-connection mode: try to delete log files if switching between read/write operations.
@changelog_1135_li
@changelog_1143_li
#CompressLZF: Faster decompress and improved javadocs
@changelog_1136_h2
@changelog_1144_h2
#Version 1.2.126 (2009-12-18)
@changelog_1137_li
@changelog_1145_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_1138_li
@changelog_1146_li
#CSVREAD: when reading the column names from the CSV file, column names that contain no special characters are considered case insensitive now.
@changelog_1139_li
@changelog_1147_li
#Optimization index conditions of the form 'column=NULL' (which is always false; unlike 'column IS NULL').
@changelog_1140_li
@changelog_1148_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_1141_li
@changelog_1149_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_1142_li
@changelog_1150_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_1143_li
@changelog_1151_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_1144_li
@changelog_1152_li
#JaQu: the decompiler has been improved, and a few test cases already work. It is still incomplete however.
@changelog_1145_li
@changelog_1153_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_1146_li
@changelog_1154_li
#The reserve heap memory is no longer used.
@changelog_1147_li
@changelog_1155_li
#Database.checkpoint() could throw a NullPointerException.
@changelog_1148_h2
@changelog_1156_h2
#Version 1.2.125 (2009-12-06)
@changelog_1149_li
@changelog_1157_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_1150_li
@changelog_1158_li
#The shell tool now has a very simple statement history.
@changelog_1151_li
@changelog_1159_li
#The zip file system implementation now supports the '~' home directory prefix. Example database URL: jdbc:h2:zip:~/test.zip!/test
@changelog_1152_li
@changelog_1160_li
#Right outer joins on tables that were already 'inner joined' was processed incorrectly.
@changelog_1153_li
@changelog_1161_li
#Temporary files from LOB objects were not deleted early enough when using the server mode.
@changelog_1154_li
@changelog_1162_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_1155_li
@changelog_1163_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_1156_li
@changelog_1164_li
#Trigger that are called before a select statement are now supported. This allows to create tables that work like materialized views.
@changelog_1157_li
@changelog_1165_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_1158_li
@changelog_1166_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_1159_li
@changelog_1167_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_1160_li
@changelog_1168_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_1161_li
@changelog_1169_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_1162_li
@changelog_1170_li
#The test cases don't access the file system directly, this simplifies GAE for Java testing. Thanks to Vince Bonfanti.
@changelog_1163_li
@changelog_1171_li
#More bugs in the server-less multi-connection mode have been fixed.
@changelog_1164_li
@changelog_1172_li
#When running against an old database, the SCRIPT statement could generate a SQL script that contained duplicate indexes (PRIMARY_KEY_E).
@changelog_1165_li
@changelog_1173_li
#JdbcConnectionPool.getConnection() could throw a NullPointerException.
@changelog_1166_li
@changelog_1174_li
#User defined functions: the source code is now available using SELECT SOURCE FROM INFORMATION_SCHEMA.FUNCTION_ALIASES.
@changelog_1167_li
@changelog_1175_li
#User defined functions with source code didn't work after re-opening the database.
@changelog_1168_li
@changelog_1176_li
#The newsfeeds are now Atom 1.0 standard compliant.
@changelog_1169_li
@changelog_1177_li
#The database is now closed after an out of memory exception, because the database could get corrupt otherwise.
@changelog_1170_li
@changelog_1178_li
#Better error message if both AUTO_SERVER and SERIALIZED parameters are set to TRUE.
@changelog_1171_li
@changelog_1179_li
#Drop table did not delete lob files in old file store (not PAGE_STORE).
@changelog_1172_h2
@changelog_1180_h2
#Version 1.2.124 (2009-11-20)
@changelog_1173_li
@changelog_1181_li
#Clustering: there is now a way to detect which cluster instances are running.
@changelog_1174_li
@changelog_1182_li
#ConvertTraceFile: the SQL statement statistics are better formatted (newline are removed).
@changelog_1175_li
@changelog_1183_li
#The file lock thread is now stopped when the database is closed.
@changelog_1176_li
@changelog_1184_li
#Issue 140: the Script tool now supports writing to a stream.
@changelog_1177_li
@changelog_1185_li
#Issue 138: the trace output of Statement.execute(String, int) and executeUpdate was incorrect.
@changelog_1178_li
@changelog_1186_li
#Page store: new databases can not be opened with older versions.
@changelog_1179_li
@changelog_1187_li
#Page store: multi-column indexes didn't work if the cache was very small.
@changelog_1180_li
@changelog_1188_li
#Page store: opening a database could theoretically result in an endless loop.
@changelog_1181_li
@changelog_1189_li
#Page store: adding large indexed columns could get very slow.
@changelog_1182_li
@changelog_1190_li
#Page store: after a duplicate key exception, an ArrayIndexOutOfBoundsException could be thrown (only for very large rows).
@changelog_1183_li
@changelog_1191_li
#Page store: the recover tool sometimes generated a script file that contained duplicate data.
@changelog_1184_li
@changelog_1192_li
#Page store: sometimes opening a read-only database failed.
@changelog_1185_li
@changelog_1193_li
#Page store: opening a database sometimes failed if large rows where updated, or if a table was truncated before.
@changelog_1186_li
@changelog_1194_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_1187_li
@changelog_1195_li
#Page store: getting the min value from a descending index with NULL entries could return the wrong result.
@changelog_1188_li
@changelog_1196_li
#Page store: improved auto-recovery after power failure.
@changelog_1189_li
@changelog_1197_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_1190_li
@changelog_1198_li
#User defined functions can be created with source code. Example: CREATE ALIAS HI AS 'String hi() { return "Hello"; }'
@changelog_1191_li
@changelog_1199_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_1192_li
@changelog_1200_li
#Inserting LOBs got slower each time the process was restarted. It could loop endlessly after about 1000 process restarts.
@changelog_1193_li
@changelog_1201_li
#Issue 117: Multi-version concurrency: concurrent MERGE statements now work.
@changelog_1194_li
@changelog_1202_li
#Improved read-only database detection.
@changelog_1195_h2
@changelog_1203_h2
#Version 1.2.123 (2009-11-08)
@changelog_1196_li
@changelog_1204_li
#Page store: new databases can not be opened with older versions.
@changelog_1197_li
@changelog_1205_li
#Page store: updating large rows (rows with more than 2000 bytes of data) could corrupt the database.
@changelog_1198_li
@changelog_1206_li
#Page store: inserting very large rows failed with ArrayIndexOutOfBoundsException.
@changelog_1199_li
@changelog_1207_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_1200_li
@changelog_1208_li
#The fulltext search methods and fields are now protected instead of private, to make the classes more easily extensible.
@changelog_1201_li
@changelog_1209_li
#The Lucene fulltext search now also returns the score.
@changelog_1202_li
@changelog_1210_li
# New function SCOPE_IDENTITY() to avoid problems when inserting rows in a trigger.
@changelog_1203_li
@changelog_1211_li
#Statement.getGeneratedKeys() returned the wrong value if a trigger changed the identity value after inserting the row.
@changelog_1204_li
@changelog_1212_li
#Improved error messages: identifiers and values are now quoted.
@changelog_1205_li
@changelog_1213_li
#Improved error message when casting a value failed: the column name and type is included in the message.
@changelog_1206_li
@changelog_1214_li
#Improved support for GAE for Java thanks to Vince Bonfanti.
@changelog_1207_h2
@changelog_1215_h2
#Version 1.2.122 (2009-10-28)
@changelog_1208_li
@changelog_1216_li
#The native fulltext search now supports streaming CLOB data.
@changelog_1209_li
@changelog_1217_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_1210_li
@changelog_1218_li
#Dropping the current user is now allowed if another admin user exists.
@changelog_1211_li
@changelog_1219_li
#Values of type BINARY or BLOB could not be converted to the data type OTHER.
@changelog_1212_li
@changelog_1220_li
#SHUTDOWN COMPACT now fully compacts the database.
@changelog_1213_li
@changelog_1221_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_1214_li
@changelog_1222_li
#New sorted insert optimization (see Performance / Database Performance Tuning).
@changelog_1215_li
@changelog_1223_li
#Issue 116: The files h2*-sources.jar and h2*-javadoc.jar are now in the Maven repository.
@changelog_1216_li
@changelog_1224_li
#Page store: opening a large database was slow if it was not closed before.
@changelog_1217_li
@changelog_1225_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_1218_li
@changelog_1226_li
#The SQL syntax is documented using (railroad) diagrams. The diagrams are HTML.
@changelog_1219_li
@changelog_1227_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_1220_li
@changelog_1228_li
#Certain queries were not sorted if subselect queries were involved
@changelog_1221_li
@changelog_1229_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_1222_h2
@changelog_1230_h2
#Version 1.2.121 (2009-10-11)
@changelog_1223_li
@changelog_1231_li
#Better support GaeVFS (Google App Engine Virtual File System) thanks to Thanks to Vince Bonfanti.
@changelog_1224_li
@changelog_1232_li
#CSVREAD didn't close the file. Thanks to Vince Bonfanti for the patch!
@changelog_1225_li
@changelog_1233_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_1226_li
@changelog_1234_li
#Page store bugs were fixed. Large values in indexed columns could corrupt the index.
@changelog_1227_li
@changelog_1235_li
#The page store did not work when using Retrotranslator (because the Retrotranslator doesn't support Integer.reverse and Long.reverse).
@changelog_1228_li
@changelog_1236_li
#New system property h2.pageStoreTrim to disable shrinking the database when closing (disabled by default, meaning by default the database is trimmed).
@changelog_1229_h2
@changelog_1237_h2
#Version 1.2.120 (2009-10-04)
@changelog_1230_li
@changelog_1238_li
#This is a beta version.
@changelog_1231_li
@changelog_1239_li
#Large updates could throw an ArrayIndexOutOfBoundsException in RowList.writeRow.
@changelog_1232_li
@changelog_1240_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_1233_li
@changelog_1241_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_1234_li
@changelog_1242_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_1235_li
@changelog_1243_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_1236_li
@changelog_1244_li
#PostgreSQL compatibility: function LASTVAL() as an alias for IDENTITY().
@changelog_1237_li
@changelog_1245_li
#Linked tables now support default values when inserting, updating or merging.
@changelog_1238_li
@changelog_1246_li
#Bugfixes in the page store.
@changelog_1239_li
@changelog_1247_li
#Possibility to set a vendor id in Constants.java, so that unofficial builds are distinguishable from official releases.
@changelog_1240_li
@changelog_1248_li
#Allow writing to linked tables in readonly databases.
@changelog_1241_h2
@changelog_1249_h2
#Version 1.1.119 (2009-09-26)
@changelog_1242_li
@changelog_1250_li
#SQL statements in the exception message are no longer included if they contain '--hide--'.
@changelog_1243_li
@changelog_1251_li
#Temporary local tables did not always work after reconnect if AUTO_SERVER=TRUE
@changelog_1244_li
@changelog_1252_li
#New system property h2.defaultMaxLengthInplaceLob to change the default maximum size of an in-place LOB object.
@changelog_1245_li
@changelog_1253_li
#New system property h2.nullConcatIsNull to change the default null concatenation behavior. The default will be enabled in version 1.2.
@changelog_1246_li
@changelog_1254_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_1247_li
@changelog_1255_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_1248_li
@changelog_1256_li
#ChangeFileEncryption did not work with Lob subdirectories. Fixed.
@changelog_1249_li
@changelog_1257_li
#Issue 121: JaQu: new simple update and merge methods.
@changelog_1250_li
@changelog_1258_li
#Issue 120: JaQu didn't close result sets.
@changelog_1251_li
@changelog_1259_li
#Issue 119: JaQu creates wrong WHERE conditions on some inputs.
@changelog_1252_li
@changelog_1260_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_1253_li
@changelog_1261_li
#SELECT COUNT(*) FROM SYSTEM_RANGE(...) returned the wrong result. Fixed.
@changelog_1254_li
@changelog_1262_li
#The Recover tool now also processes the log files, however applying those changes is still a manual process.
@changelog_1255_li
@changelog_1263_li
#New sample application that shows how to pass data to a trigger.
@changelog_1256_li
@changelog_1264_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_1257_li
@changelog_1265_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_1258_li
@changelog_1266_li
#Updating many rows with the same CLOB or BLOB values could result in FileNotFoundException.
@changelog_1259_li
@changelog_1267_li
#Statement.getConnection() threw an exception if the connection was already closed.
@changelog_1260_li
@changelog_1268_li
#The native fulltext index kept a reference to a database after the database was closed.
@changelog_1261_li
@changelog_1269_li
#Non-unique in-memory hash indexes are now supported. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1262_li
@changelog_1270_li
#The optimizer does a better job for joins if indexes are missing.
@changelog_1263_h2
@changelog_1271_h2
#Version 1.1.118 (2009-09-04)
@changelog_1264_li
@changelog_1272_li
#SHOW COLUMNS only listed indexed columns.
@changelog_1265_li
@changelog_1273_li
#When calling SHUTDOWN IMMEDIATELY in the server mode, the .trace.db file was not closed.
@changelog_1266_li
@changelog_1274_li
#DatabaseMetaData.getPrimaryKeys: the wrong constraint name was reported if there was another constraint on the same table and columns.
@changelog_1267_li
@changelog_1275_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_1268_li
@changelog_1276_li
#Native fulltext search: before searching, FT_INIT() had to be called. This is no longer required.
@changelog_1269_li
@changelog_1277_li
#Better support GaeVFS (Google App Engine Virtual File System).
@changelog_1270_li
@changelog_1278_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_1271_li
@changelog_1279_li
#Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1272_li
@changelog_1280_li
#PreparedStatement.setObject now converts a java.lang.Character to a string.
@changelog_1273_li
@changelog_1281_li
#H2 Console: PierPaolo Ucchino has completed the Italian translation. Thanks a lot!
@changelog_1274_li
@changelog_1282_li
#Various tools now use Java 5 var-args, such as main the methods and SimpleResultSet.addRow.
@changelog_1275_li
@changelog_1283_li
#H2 Console: indexes of tables of non-default schemas are now also listed.
@changelog_1276_li
@changelog_1284_li
#Issue 111: Multi-version concurrency / duplicate primary key after rollback.
@changelog_1277_li
@changelog_1285_li
#Issue 110: Multi-version concurrency / wrong exception is thrown.
@changelog_1278_li
@changelog_1286_li
#Parser: sequenceName.NEXTVAL and CURRVAL did not respect the schema search path.
@changelog_1279_li
@changelog_1287_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_1280_li
@changelog_1288_li
#The stack trace of very common exceptions is no longer written to the .trace.db file by default.
@changelog_1281_li
@changelog_1289_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_1282_li
@changelog_1290_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_1283_h2
@changelog_1291_h2
#Version 1.1.117 (2009-08-09)
@changelog_1284_li
@changelog_1292_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_1285_li
@changelog_1293_li
#JaQu: the order of the fields in the database no longer needs to match the order in the database.
@changelog_1286_li
@changelog_1294_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_1287_li
@changelog_1295_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_1288_li
@changelog_1296_li
#Views using functions were not re-evaluated when necessary.
@changelog_1289_li
@changelog_1297_li
#Improved MySQL compatibility for SHOW COLUMNS.
@changelog_1290_li
@changelog_1298_li
#Improved PostgreSQL compatibility for timestamp literals with timezone.
@changelog_1291_li
@changelog_1299_li
#Sergi Vladykin translated the error messages to Russian. Thanks a lot!
@changelog_1292_li
@changelog_1300_li
#Support for Java 6 DatabaseMetaData.getTables, getColumns, getProcedures, and getProcedureColumns.
@changelog_1293_li
@changelog_1301_li
#Issue 101: Rollback of a large transaction (more than 100000 rows) could fail.
@changelog_1294_li
@changelog_1302_li
#Various bugfixes and improvements in the page store mechanism (still experimental).
@changelog_1295_li
@changelog_1303_li
#The functions LENGTH, OCTET_LENGTH, and BIT_LENGTH now return BIGINT.
@changelog_1296_li
@changelog_1304_li
#Data types CLOB and BLOB: the maximum precision was Integer.MAX_VALUE, it is now Long.MAX_VALUE.
@changelog_1297_li
@changelog_1305_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_1298_li
@changelog_1306_li
#Parsing SQL script files is now faster.
@changelog_1299_li
@changelog_1307_li
#CSV reading is now faster.
@changelog_1300_li
@changelog_1308_li
#SimpleResultSet.newInstance(SimpleRowSource rs) did not work.
@changelog_1301_h2
@changelog_1309_h2
#Version 1.1.116 (2009-07-18)
@changelog_1302_li
@changelog_1310_li
#Server-less multi-connection mode: more bugs are fixed.
@changelog_1303_li
@changelog_1311_li
#The built-in help (INFORMATION_SCHEMA.HELP) is smaller, shrinking the jar file size a bit.
@changelog_1304_li
@changelog_1312_li
#H2 Console: column of tables of non-default schemas are now also listed, except for schemas starting with 'INFO'.
@changelog_1305_li
@changelog_1313_li
#ALTER TABLE: removing an auto-increment or identity column didn't remove the sequence.
@changelog_1306_li
@changelog_1314_li
#Creating indexes is now a bit faster.
@changelog_1307_li
@changelog_1315_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_1308_li
@changelog_1316_li
#PG Server: improved compatibility by using the type ids of the PostgreSQL driver. Thanks a lot to Sergi Vladykin for the patch!
@changelog_1309_li
@changelog_1317_li
#H2 Console: Oracle system tables are no longer listed, improving performance.
@changelog_1310_li
@changelog_1318_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_1311_li
@changelog_1319_li
#New system property h2.defaultResultSetConcurrency to change the default result set concurrency.
@changelog_1312_li
@changelog_1320_li
#JDBC: using an invalid result set type or concurrency now throws an exception.
@changelog_1313_li
@changelog_1321_li
#If a pooled connection was not closed but garbage collected, a NullPointerException could occur.
@changelog_1314_li
@changelog_1322_li
#Fulltext search: a NullPointerException was thrown when updating a value that was NULL previously.
@changelog_1315_li
@changelog_1323_li
#The Recover tool did not work with .data.db files of the wrong size.
@changelog_1316_li
@changelog_1324_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_1317_li
@changelog_1325_li
#The soft-references cache (CACHE_TYPE=SOFT_LRU) could throw a NullPointerException.
@changelog_1318_li
@changelog_1326_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_1319_h2
@changelog_1327_h2
#Version 1.1.115 (2009-06-21)
@changelog_1320_li
@changelog_1328_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_1321_li
@changelog_1329_li
#ALTER TABLE could throw an exception "object already exists" in some cases.
@changelog_1322_li
@changelog_1330_li
#Views: in some situations, an ArrayIndexOutOfBoundsException was thrown when using the same view concurrently.
@changelog_1323_li
@changelog_1331_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_1324_li
@changelog_1332_li
#H2 Console: the language was reset to the browser language when disconnecting.
@changelog_1325_li
@changelog_1333_li
#H2 Console: improved Polish translation.
@changelog_1326_li
@changelog_1334_li
#Server-less multi-connection mode: more bugs are fixed.
@changelog_1327_li
@changelog_1335_li
#The download page now included the SHA1 checksums.
@changelog_1328_li
@changelog_1336_li
#Shell tool: the file encoding workaround is now documented if you run java org.h2.tools.Shell -?.
@changelog_1329_li
@changelog_1337_li
#The RunScript tool and SQL statement did not work with the compression method LZF.
@changelog_1330_li
@changelog_1338_li
#Fulltext search: searching for NULL or an empty string threw an exception.
@changelog_1331_li
@changelog_1339_li
#Lucene fulltext search: FTL_DROP_ALL did not drop the triggers.
@changelog_1332_li
@changelog_1340_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_1333_li
@changelog_1341_li
#Data types: LONG is now an alias for BIGINT.
@changelog_1334_h2
@changelog_1342_h2
#Version 1.1.114 (2009-06-01)
@changelog_1335_li
@changelog_1343_li
#ResultSetMetaData.getColumnClassName returned the wrong class for CLOB and BLOB columns.
@changelog_1336_li
@changelog_1344_li
#Fulltext search: data is no longer deleted and re-inserted if the indexed columns didn't change.
@changelog_1337_li
@changelog_1345_li
#In some situations, an ArrayIndexOutOfBoundsException was thrown when adding rows. This was caused by a bug in the b-tree code.
@changelog_1338_li
@changelog_1346_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_1339_li
@changelog_1347_li
#The Recover tool did not always work when the database contains referential integrity constraints.
@changelog_1340_li
@changelog_1348_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/).
@cheatSheet_1000_h1
...
...
@@ -2672,177 +2696,180 @@ F A Q
# Usually, bugs get fixes as they are found. There is a release every few weeks. Here is the list of known and confirmed issues:
@faq_1019_li
#Tomcat and Glassfish 3 set most static fields (final or non-final) to <code>null</code> when unloading a web application. This can cause a <code>NullPointerException</code> in H2 versions 1.1.107 and older, and may still not work in newer versions. Please report it if you run into this issue. In Tomcat >= 6.0 this behavior can be disabled by setting the system property <code>org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false</code>, however Tomcat may then run out of memory. A known workaround is to put the <code>h2*.jar</code> file in a shared <code>lib</code> directory (<code>common/lib</code>).
#Apache Harmony: there seems to be a bug in Harmony that affects H2. See <a href="https://issues.apache.org/jira/browse/HARMONY-6505">HARMONY-6505</a>.
@faq_1020_li
#Some problems have been found with right outer join. Internally, it is converted to left outer join, which does not always produce the same results as other databases when used in combination with other joins.
#Tomcat and Glassfish 3 set most static fields (final or non-final) to <code>null</code> when unloading a web application. This can cause a <code>NullPointerException</code> in H2 versions 1.1.107 and older, and may still not work in newer versions. Please report it if you run into this issue. In Tomcat >= 6.0 this behavior can be disabled by setting the system property <code>org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false</code>, however Tomcat may then run out of memory. A known workaround is to put the <code>h2*.jar</code> file in a shared <code>lib</code> directory (<code>common/lib</code>).
@faq_1021_li
#Some problems have been found with right outer join. Internally, it is converted to left outer join, which does not always produce the same results as other databases when used in combination with other joins.
@faq_1022_li
#When using Install4j before 4.1.4 on Linux and enabling <code>pack200</code>, the <code>h2*.jar</code> becomes corrupted by the install process, causing application failure. A workaround is to add an empty file <code>h2*.jar.nopack</code> next to the <code>h2*.jar</code> file. This problem is solved in Install4j 4.1.4.
@faq_1022_p
@faq_1023_p
# For a complete list, see <a href="http://code.google.com/p/h2database/issues/list">Open Issues</a>.
@faq_1023_h3
@faq_1024_h3
このデータベースエンジンはオープンソースですか？
@faq_1024_p
@faq_1025_p
# Yes. It is free to use and distribute, and the source code is included. See also under license.
@faq_1025_h3
@faq_1026_h3
#My Query is Slow
@faq_1026_p
@faq_1027_p
# Slow <code>SELECT</code> (or <code>DELETE, UPDATE, MERGE</code>) statement can have multiple reasons. Follow this checklist:
@faq_1027_li
@faq_1028_li
#Run <code>ANALYZE</code> (see documentation for details).
@faq_1028_li
@faq_1029_li
#Run the query with <code>EXPLAIN</code> and check if indexes are used (see documentation for details).
@faq_1029_li
@faq_1030_li
#If required, create additional indexes and try again using <code>ANALYZE</code> and <code>EXPLAIN</code>.
@faq_1030_li
@faq_1031_li
#If it doesn't help please report the problem.
@faq_1031_h3
@faq_1032_h3
新規データベースの構築方法は？
@faq_1032_p
@faq_1033_p
# By default, a new database is automatically created if it does not yet exist. See <a href="tutorial.html#creating_new_databases">Creating New Databases</a>.
@faq_1033_h3
@faq_1034_h3
データベースへの接続方法は？
@faq_1034_p
@faq_1035_p
# The database driver is <code>org.h2.Driver</code>, and the database URL starts with <code>jdbc:h2:</code>. To connect to a database using JDBC, use the following code:
@faq_1035_h3
@faq_1036_h3
データベースのファイルはどこに保存されますか？
@faq_1036_p
@faq_1037_p
# When using database URLs like <code>jdbc:h2:~/test</code>, the database is stored in the user directory. For Windows, this is usually <code>C:\Documents and Settings\<userName></code>. If the base directory is not set (as in <code>jdbc:h2:test</code>), the database files are stored in the directory where the application is started (the current working directory). When using the H2 Console application from the start menu, this is <code><Installation Directory>/bin</code>. The base directory can be set in the database URL. A fixed or relative path can be used. When using the URL <code>jdbc:h2:file:data/sample</code>, the database is stored in the directory <code>data</code> (relative to the current working directory). The directory is created automatically if it does not yet exist. It is also possible to use the fully qualified directory name (and for Windows, drive name). Example: <code>jdbc:h2:file:C:/data/test</code>
@faq_1037_h3
@faq_1038_h3
#What is the Size Limit (Maximum Size) of a Database?
@faq_1038_p
@faq_1039_p
# See <a href="advanced.html#limits_limitations">Limits and Limitations</a>.
@faq_1039_h3
@faq_1040_h3
これは信頼できるデータベースですか？
@faq_1040_p
@faq_1041_p
# That is not easy to say. It is still a quite new product. A lot of tests have been written, and the code coverage of these tests is very high. Randomized stress tests are run regularly. But there are probably still bugs that have not yet been found (as with most software). Some features are known to be dangerous, they are only supported for situations where performance is more important than reliability. Those dangerous features are:
@faq_1041_li
@faq_1042_li
#Using the transaction isolation level <code>READ_UNCOMMITTED</code> (<code>LOCK_MODE 0</code>) while at the same time using multiple connections.
@faq_1042_li
@faq_1043_li
#Disabling database file protection using <code>FILE_LOCK=NO</code> in the database URL.
@faq_1043_li
@faq_1044_li
#Disabling referential integrity using <code>SET REFERENTIAL_INTEGRITY FALSE</code>.
@faq_1044_p
@faq_1045_p
# In addition to that, running out of memory should be avoided. In older versions, OutOfMemory errors while using the database could corrupt a databases.
@faq_1045_p
@faq_1046_p
# Some areas of this database are not fully tested. When using one of those features for production, please ensure your use case is well tested (if possible with automated test cases). Those areas are:
@faq_1046_li
@faq_1047_li
#Platforms other than Windows XP, Linux, Mac OS X, or JVMs other than Sun 1.5 or 1.6
@faq_1047_li
@faq_1048_li
#The features <code>AUTO_SERVER</code> and <code>AUTO_RECONNECT</code>
@faq_1048_li
@faq_1049_li
#The file locking method 'Serialized'
@faq_1049_li
@faq_1050_li
#The MVCC (multi version concurrency) mode
@faq_1050_li
@faq_1051_li
#Cluster mode, 2-phase commit, savepoints
@faq_1051_li
@faq_1052_li
#24/7 operation
@faq_1052_li
@faq_1053_li
#Some operations on databases larger than 500 MB may be slower than expected
@faq_1053_li
@faq_1054_li
#The optimizer may not always select the best plan
@faq_1054_li
@faq_1055_li
#Fulltext search
@faq_1055_li
@faq_1056_li
#Operations on LOBs over 2 GB
@faq_1056_p
@faq_1057_p
# Areas considered experimental are:
@faq_1057_li
@faq_1058_li
#The PostgreSQL server
@faq_1058_li
@faq_1059_li
#Multi-threading within the engine using <code>SET MULTI_THREADED=1</code>
@faq_1059_li
@faq_1060_li
#Compatibility modes for other databases (only some features are implemented)
@faq_1060_li
@faq_1061_li
#The soft reference cache (CACHE_TYPE=SOFT_LRU). It might not improve performance, and out of memory issues have been reported.
@faq_1061_p
@faq_1062_p
# Some users have reported that after a power failure, the database cannot be opened sometimes. In this case, use a backup of the database or the Recover tool. Please report such problems. The plan is that the database automatically recovers in all situations.
@faq_1062_h3
@faq_1063_h3
#Column Names are Incorrect?
@faq_1063_p
@faq_1064_p
# For the query <code>SELECT ID AS X FROM TEST</code> the method <code>ResultSetMetaData.getColumnName()</code> returns <code>ID</code>, I expect it to return <code>X</code>. What's wrong?
@faq_1064_p
@faq_1065_p
# This is not a bug. According the the JDBC specification, the method <code>ResultSetMetaData.getColumnName()</code> should return the name of the column and not the alias name. If you need the alias name, use <a href="http://java.sun.com/javase/6/docs/api/java/sql/ResultSetMetaData.html#getColumnLabel(int)"><code>ResultSetMetaData.getColumnLabel()</code></a>. Other database don't work like this (they don't follow the JDBC specification). If you need compatibility with those databases, use the <a href="features.html#compatibility">Compatibility Mode</a>, or set the system property <a href="../javadoc/org/h2/constant/SysProperties.html#h2.aliasColumnName"><code>h2.aliasColumnName</code></a>.
@faq_1065_p
@faq_1066_p
# This also applies to DatabaseMetaData calls that return a result set. The columns in the JDBC API are column labels, not column names.
@faq_1066_h3
@faq_1067_h3
#Float is Double?
@faq_1067_p
@faq_1068_p
# For a table defined as <code>CREATE TABLE TEST(X FLOAT)</code> the method <code>ResultSet.getObject()</code> returns a <code>java.lang.Double</code>, I expect it to return a <code>java.lang.Float</code>. What's wrong?
@faq_1068_p
@faq_1069_p
# This is not a bug. According the the JDBC specification, the JDBC data type <code>FLOAT</code> is equivalent to <code>DOUBLE</code>, and both are mapped to <code>java.lang.Double</code>. See also <a href="http://java.sun.com/j2se/1.5.0/docs/guide/jdbc/getstart/mapping.html#1055162"> Mapping SQL and Java Types - 8.3.10 FLOAT</a>.
@faq_1069_h3
@faq_1070_h3
#Why is Opening my Database Slow?
@faq_1070_p
@faq_1071_p
# To find out what the problem is, use the H2 Console and click on "Test Connection" instead of "Login". After the "Login Successful" appears, click on it (it's a link). This will list the top stack traces. Then either analyze this yourself, or post those stack traces in the Google Group.
@faq_1071_p
@faq_1072_p
# To find out what the problem is, open the database in embedded mode using the H2 Console. This will print progress information. If you have many lines with 'Creating index' it is an indication that the database was not closed the last time.
@faq_1072_p
@faq_1073_p
# Other possible reasons are: the database is very big (many GB), or contains linked tables that are slow to open.
@faq_1073_h3
@faq_1074_h3
#Is the GCJ Version Stable? Faster?
@faq_1074_p
@faq_1075_p
# The GCJ version is not as stable as the Java version. When running the regression test with the GCJ version, sometimes the application just stops at what seems to be a random point without error message. Currently, the GCJ version is also slower than when using the Sun VM. However, the startup of the GCJ version is faster than when using a VM.
@faq_1075_h3
@faq_1076_h3
このプロジェクトの翻訳方法は？
@faq_1076_p
@faq_1077_p
# For more information, see <a href="build.html#translating">Build/Translating</a>.
@features_1000_h1
...
...
@@ -9517,16 +9544,19 @@ H2 コンソール アプリケーション
@roadmap_1448_li
#Maybe use a different page layout: keep the data at the head of the page, and ignore the tail (don't store / read it). This may increase write / read performance depending on the file system.
@roadmap_1449_h2
@roadmap_1449_li
#Indexes of temporary tables are currently kept in-memory. Is this how it should be?
@roadmap_1450_h2
#Not Planned
@roadmap_1450_li
@roadmap_1451_li
#HSQLDB (did) support this: select id i from test where i<0 (other databases don't). Supporting it may break compatibility.
@roadmap_1451_li
@roadmap_1452_li
#String.intern (so that Strings can be compared with ==) will not be used because some VMs have problems when used extensively.
@roadmap_1452_li
@roadmap_1453_li
#In prepared statements, identifier names (table names and so on) can not be parameterized. Adding such a feature would complicate the source code without providing reasonable speedup, and would slow down regular prepared statements.
@sourceError_1000_h1
...
...
@@ -9980,7 +10010,7 @@ TCPサーバーに接続する
Hibernateを使用する
@tutorial_1137_p
# This database supports Hibernate version 3.1 and newer. You can use the HSQLDB Dialect, or the native H2 Dialect. Unfortunately the H2 Dialect included in Hibernate is buggy. A <a href="http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401">patch for Hibernate</a> has been submitted. The dialect for the newest version of Hibernate is also available at <code>src/tools/org/hibernate/dialect/H2Dialect.java.txt</code>. You can rename it to <code>H2Dialect.java</code> and include this as a patch in your application.
# This database supports Hibernate version 3.1 and newer. You can use the HSQLDB Dialect, or the native H2 Dialect. Unfortunately the H2 Dialect included in some versions of Hibernate is buggy. A <a href="http://opensource.atlassian.com/projects/hibernate/browse/HHH-3401">patch for Hibernate</a> has been submitted and is now applied. The dialect for the newest version of Hibernate is also available at <code>src/tools/org/hibernate/dialect/H2Dialect.java.txt</code>. You can rename it to <code>H2Dialect.java</code> and include this as a patch in your application, or upgrade to a version of Hibernate where this is fixed.
