org.h2.constant
Class SysProperties

java.lang.Object
  extended by org.h2.constant.SysProperties

public class SysProperties
extends java.lang.Object

The constants defined in this class are initialized from system properties. Those properties can be set when starting the virtual machine:

 java -Dh2.baseDir=/temp
 
They can be set within the application, but this must be done before loading any classes of this database (before loading the JDBC driver):
 System.setProperty("h2.baseDir", "/temp");
 


Field Summary
static boolean ALIAS_COLUMN_NAME
          System property h2.aliasColumnName.
When enabled, aliased columns (as in SELECT ID AS I FROM TEST) return the alias (I in this case) in ResultSetMetaData.getColumnName() and 'null' in getTableName().
static boolean ALLOW_BIG_DECIMAL_EXTENSIONS
          System property h2.allowBigDecimalExtensions (default: false).
When enabled, classes that extend BigDecimal are supported in PreparedStatement.setBigDecimal.
static java.lang.String ALLOWED_CLASSES
          System property h2.allowedClasses (default: *).
Comma separated list of class names or prefixes.
static java.lang.String BIND_ADDRESS
          System property h2.bindAddress (default: *).
Comma separated list of class names or prefixes.
static java.lang.String BROWSER
          System property h2.browser (default: null).
The preferred browser to use.
static int CACHE_SIZE_DEFAULT
          System property h2.cacheSizeDefault (default: 16384).
The default cache size in KB.
static int CACHE_SIZE_INDEX_DEFAULT
          INTERNAL
static int CACHE_SIZE_INDEX_SHIFT
          System property h2.cacheSizeIndexShift (default: 3).
How many time the cache size value is divided by two to get the index cache size.
static java.lang.String CACHE_TYPE_DEFAULT
          System property h2.cacheTypeDefault (default: LRU).
How many time the cache size value is divided by two to get the index cache size.
static boolean CHECK
          System property h2.check (default: true).
Assertions in the database engine.
static boolean CHECK2
          System property h2.check2 (default: true).
Additional assertions in the database engine.
static java.lang.String CLIENT_TRACE_DIRECTORY
          System property h2.clientTraceDirectory (default: trace.db/).
Directory where the trace files of the JDBC client are stored (only for client / server).
static int COLLATOR_CACHE_SIZE
          System property h2.collatorCacheSize (default: 10000).
The cache size for collation keys (in elements).
static int DATASOURCE_TRACE_LEVEL
          System property h2.dataSourceTraceLevel (default: 1).
The trace level of the data source implementation.
static java.lang.Character DEFAULT_ESCAPE_CHAR
          System property h2.defaultEscape (default: \).
The default escape character for LIKE comparisons.
static int DEFAULT_LOCK_MODE
          System property h2.defaultLockMode (default: 3).
The default value for the LOCK_MODE setting.
static int DEFAULT_MAX_LENGTH_INPLACE_LOB
          System property h2.defaultMaxLengthInplaceLob.
The default maximum length of an LOB that is stored in the data file itself.
static int DEFAULT_MAX_MEMORY_UNDO
          System property h2.defaultMaxMemoryUndo (default: 50000).
The default value for the MAX_MEMORY_UNDO setting.
static int DEFAULT_MAX_OPERATION_MEMORY
          System property h2.defaultMaxOperationMemory (default: 100000).
The default for the setting MAX_OPERATION_MEMORY.
static int DEFAULT_RESULT_SET_CONCURRENCY
          System property h2.defaultResultSetConcurrency (default: ResultSet.CONCUR_READ_ONLY).
The default result set concurrency for statements created with Connection.createStatement() or prepareStatement(String sql).
static int DELAY_WRONG_PASSWORD_MAX
          System property h2.delayWrongPasswordMax (default: 4000).
The maximum delay in milliseconds before an exception is thrown for using the wrong user name or password.
static int DELAY_WRONG_PASSWORD_MIN
          System property h2.delayWrongPasswordMin (default: 250).
The minimum delay in milliseconds before an exception is thrown for using the wrong user name or password.
static boolean DOLLAR_QUOTING
          System property h2.dollarQuoting (default: true).
Dollar quoting is used to quote text without having to use escape characters.
static boolean ENABLE_ANONYMOUS_SSL
          System property h2.enableAnonymousSSL (default: true).
When using SSL connection, the anonymous cipher suite SSL_DH_anon_WITH_RC4_128_MD5 should be enabled.
static int ESTIMATED_FUNCTION_TABLE_ROWS
          System property h2.estimatedFunctionTableRows (default: 1000).
The estimated number of rows in a function table (for example, CSVREAD or FTL_SEARCH).
static java.lang.String FILE_ENCODING
          System property file.encoding (default: Cp1252).
It is usually set by the system and is the default encoding used for the RunScript and CSV tool.
static java.lang.String FILE_SEPARATOR
          System property file.separator (default: /).
It is usually set by the system, and used to build absolute file names.
static java.lang.String H2_COLLATOR_CACHE_SIZE
          INTERNAL
static java.lang.String H2_LOG_DELETE_DELAY
          INTERNAL
static java.lang.String H2_MAX_QUERY_TIMEOUT
          INTERNAL
static java.lang.String H2_PAGE_STORE
          INTERNAL
static java.lang.String JAVA_SPECIFICATION_VERSION
          System property java.specification.version.
It is set by the system.
static int LARGE_RESULT_BUFFER_SIZE
          System property h2.largeResultBufferSize (default: 4096).
Buffer size for large result sets.
static java.lang.String LINE_SEPARATOR
          System property line.separator (default: \n).
It is usually set by the system, and used by the script and trace tools.
static boolean LOB_FILES_IN_DIRECTORIES
          System property h2.lobFilesInDirectories.
Store LOB files in subdirectories.
static int LOB_FILES_PER_DIRECTORY
          System property h2.lobFilesPerDirectory (default: 256).
Maximum number of LOB files per directory.
static boolean lobCloseBetweenReads
          System property h2.lobCloseBetweenReads (default: false).
Close LOB files between read operations.
static boolean LOG_ALL_ERRORS
          System property h2.logAllErrors (default: false).
Write stack traces of any kind of error to a file.
static java.lang.String LOG_ALL_ERRORS_FILE
          System property h2.logAllErrorsFile (default: h2errors.txt).
File name to log errors.
static int MAX_FILE_RETRY
          System property h2.maxFileRetry (default: 16).
Number of times to retry file delete and rename.
static int MAX_MEMORY_ROWS_DISTINCT
          System property h2.maxMemoryRowsDistinct (default: Integer.MAX_VALUE).
The maximum number of rows kept in-memory for SELECT DISTINCT queries.
static int MAX_QUERY_TIMEOUT
          System property h2.maxQueryTimeout (default: 0).
The maximum timeout of a query.
static int MAX_RECONNECT
          System property h2.maxReconnect (default: 3).
The maximum number of tries to reconnect in a row.
static long MAX_TRACE_DATA_LENGTH
          System property h2.maxTraceDataLength (default: 65535).
The maximum size of a LOB value that is written as data to the trace system.
static int MIN_COLUMN_NAME_MAP
          System property h2.minColumnNameMap (default: 3).
The minimum number of columns where a hash table is created when result set methods with column name (instead of column index) parameter are called.
static int MIN_WRITE_DELAY
          System property h2.minWriteDelay (default: 5).
The minimum write delay that causes commits to be delayed.
static boolean NIO_CLEANER_HACK
          System property h2.nioCleanerHack (default: true).
If possible, use a hack to un-map the mapped file.
static boolean NIO_LOAD_MAPPED
          System property h2.nioLoadMapped (default: false).
If the mapped buffer should be loaded when the file is opened.
static boolean NULL_CONCAT_IS_NULL
          System property h2.nullConcatIsNull.
Concatenation with NULL results in NULL.
static boolean OBJECT_CACHE
          System property h2.objectCache (default: true).
Cache commonly used objects (integers, strings).
static int OBJECT_CACHE_MAX_PER_ELEMENT_SIZE
          System property h2.objectCacheMaxPerElementSize (default: 4096).
Maximum size of an object in the cache.
static int OBJECT_CACHE_SIZE
          System property h2.objectCacheSize (default: 1024).
Maximum size of an object in the cache.
static boolean OLD_COMMAND_LINE_OPTIONS
          System property h2.oldCommandLineOptions.
Support old command line options.
static boolean OPTIMIZE_DISTINCT
          System property h2.optimizeDistinct (default: true).
Improve the performance of simple DISTINCT queries if an index is available for the given column.
static boolean OPTIMIZE_DROP_DEPENDENCIES
          System property h2.optimizeDropDependencies (default: true).
Improve the performance of DROP and DROP ALL OBJECTS by quicker scanning if other objects depend on this object.
static boolean OPTIMIZE_EVALUATABLE_SUBQUERIES
          System property h2.optimizeEvaluatableSubqueries (default: true).
Optimize subqueries that are not dependent on the outer query.
static boolean OPTIMIZE_GROUP_SORTED
          System property h2.optimizeGroupSorted.
Optimize GROUP BY queries if an index can be used that matches the group by columns.
static boolean OPTIMIZE_IN
          System property h2.optimizeIn (default: true).
Optimize IN(...) comparisons.
static boolean OPTIMIZE_IN_LIST
          System property h2.optimizeInList (default: false).
Optimize IN(...) and IN(SELECT ...) comparisons.
static boolean OPTIMIZE_MIN_MAX
          System property h2.optimizeMinMax (default: true).
Optimize MIN and MAX aggregate functions.
static boolean OPTIMIZE_NOT
          System property h2.optimizeNot (default: true).
Optimize NOT conditions by removing the NOT and inverting the condition.
static boolean OPTIMIZE_OR
          System property h2.optimizeOr (default: false).
Convert (C=? OR C=?) to (C IN(?, ?)).
static boolean OPTIMIZE_SUBQUERY_CACHE
          System property h2.optimizeSubqueryCache (default: true).
Cache subquery results.
static boolean OPTIMIZE_TWO_EQUALS
          System property h2.optimizeTwoEquals (default: true).
Optimize expressions of the form A=B AND B=1.
static boolean optimizeInJoin
          System property h2.optimizeInJoin (default: false).
Optimize IN(...) comparisons by converting them to inner joins.
static boolean OVERFLOW_EXCEPTIONS
          System property h2.overflowExceptions (default: true).
Throw an exception on integer overflows.
static boolean PAGE_STORE
          System property h2.pageStore.
Use the 'page store' database file format for new databases.
static java.lang.String PG_DEFAULT_CLIENT_ENCODING
          System property h2.pgClientEncoding (default: UTF-8).
Default client encoding for PG server.
static boolean RECOMPILE_ALWAYS
          System property h2.recompileAlways (default: false).
Always recompile prepared statements.
static int RECONNECT_CHECK_DELAY
          System property h2.reconnectCheckDelay (default: 200).
Check the .lock.db file every this many milliseconds to detect that the database was changed.
static int REDO_BUFFER_SIZE
          System property h2.redoBufferSize (default: 262144).
Size of the redo buffer (used at startup when recovering).
static int RESERVE_MEMORY
          System property h2.reserveMemory (default: 524288).
This many bytes in main memory are allocated as a reserve.
static boolean RETURN_LOB_OBJECTS
          System property h2.returnLobObjects.
When true, ResultSet.getObject for CLOB or BLOB will return a java.sql.Clob / java.sql.Blob object.
static int REUSE_SPACE_AFTER
          System property h2.reuseSpaceAfter (default: 16).
Reuse space in database files after this many pages are free.
static boolean REUSE_SPACE_BTREE_INDEX
          System property h2.reuseSpaceBtreeIndex (default: true).
Reuse space after deleting or updating many rows in a b-tree index.
static boolean REUSE_SPACE_QUICKLY
          System property h2.reuseSpaceQuickly (default: true).
Reuse space in database files quickly.
static boolean runFinalize
          System property h2.runFinalize (default: true).
Run finalizers to detect unclosed connections.
static int SERVER_CACHED_OBJECTS
          System property h2.serverCachedObjects (default: 64).
TCP Server: number of cached objects per session.
static int SERVER_RESULT_SET_FETCH_SIZE
          System property h2.serverResultSetFetchSize (default: 100).
The default result set fetch size when using the server mode.
static boolean SHARE_LINKED_CONNECTIONS
          System property h2.shareLinkedConnections.
Linked connections should be shared, that means connections to the same database should be used for all linked tables that connect to the same database.
static int SOCKET_CONNECT_TIMEOUT
          System property h2.socketConnectTimeout (default: 2000).
The timeout in milliseconds to connect to a server.
static boolean SORT_NULLS_HIGH
          System property h2.sortNullsHigh (default: false).
Invert the default sorting behavior for NULL values, such that NULL values are sorted to the end of a result set in an ascending sort and to the beginning of a result set in a descending sort.
static long SPLIT_FILE_SIZE_SHIFT
          System property h2.splitFileSizeShift (default: 30).
The maximum file size of a split file is 1L << x.
static long TIME_START
          The current time this class was loaded (in milliseconds).
static boolean TRACE_IO
          System property h2.traceIO (default: false).
Trace all I/O operations.
static java.lang.String USER_HOME
          System property user.home (default: empty string).
It is usually set by the system, and used as a replacement for ~ in file names.
static int WEB_MAX_VALUE_LENGTH
          System property h2.webMaxValueLength (default: 10000).
The H2 Console will abbreviate result values larger than this size.
 
Method Summary
static java.lang.String getBaseDir()
          INTERNAL
static int getCollatorCacheSize()
          INTERNAL
static int getIntSetting(java.lang.String name, int defaultValue)
          INTERNAL
static int getLogFileDeleteDelay()
          INTERNAL
static int getMaxQueryTimeout()
          INTERNAL
static boolean getPageStore()
          INTERNAL
static java.lang.String getScriptDirectory()
          INTERNAL.
static java.lang.String getStringSetting(java.lang.String name, java.lang.String defaultValue)
          INTERNAL
static void setBaseDir(java.lang.String dir)
          INTERNAL
static void setScriptDirectory(java.lang.String dir)
          INTERNAL
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

H2_MAX_QUERY_TIMEOUT

public static final java.lang.String H2_MAX_QUERY_TIMEOUT
INTERNAL

See Also:
Constant Field Values

H2_LOG_DELETE_DELAY

public static final java.lang.String H2_LOG_DELETE_DELAY
INTERNAL

See Also:
Constant Field Values

H2_COLLATOR_CACHE_SIZE

public static final java.lang.String H2_COLLATOR_CACHE_SIZE
INTERNAL

See Also:
Constant Field Values

H2_PAGE_STORE

public static final java.lang.String H2_PAGE_STORE
INTERNAL

See Also:
Constant Field Values

FILE_ENCODING

public static final java.lang.String FILE_ENCODING
System property file.encoding (default: Cp1252).
It is usually set by the system and is the default encoding used for the RunScript and CSV tool.


FILE_SEPARATOR

public static final java.lang.String FILE_SEPARATOR
System property file.separator (default: /).
It is usually set by the system, and used to build absolute file names.


JAVA_SPECIFICATION_VERSION

public static final java.lang.String JAVA_SPECIFICATION_VERSION
System property java.specification.version.
It is set by the system. Examples: 1.4, 1.5, 1.6.


LINE_SEPARATOR

public static final java.lang.String LINE_SEPARATOR
System property line.separator (default: \n).
It is usually set by the system, and used by the script and trace tools.


USER_HOME

public static final java.lang.String USER_HOME
System property user.home (default: empty string).
It is usually set by the system, and used as a replacement for ~ in file names.


ALIAS_COLUMN_NAME

public static final boolean ALIAS_COLUMN_NAME
System property h2.aliasColumnName.
When enabled, aliased columns (as in SELECT ID AS I FROM TEST) return the alias (I in this case) in ResultSetMetaData.getColumnName() and 'null' in getTableName(). If disabled, the real column name (ID in this case) and table name is returned. This setting only affects the default mode.

When using different modes, this feature is disabled for compatibility for all databases except MySQL. For MySQL, it is always enabled.

In version 1.0, it is enabled by default.

In version 1.1, it is disabled by default.


ALLOW_BIG_DECIMAL_EXTENSIONS

public static final boolean ALLOW_BIG_DECIMAL_EXTENSIONS
System property h2.allowBigDecimalExtensions (default: false).
When enabled, classes that extend BigDecimal are supported in PreparedStatement.setBigDecimal.


ALLOWED_CLASSES

public static final java.lang.String ALLOWED_CLASSES
System property h2.allowedClasses (default: *).
Comma separated list of class names or prefixes.


BROWSER

public static final java.lang.String BROWSER
System property h2.browser (default: null).
The preferred browser to use. If not set, the default browser is used. For Windows, to use the Internet Explorer, set this property to 'explorer'. For Mac OS, if the default browser is not Safari and you want to use Safari, use: java -Dh2.browser="open,-a,Safari,%url" ....


ENABLE_ANONYMOUS_SSL

public static final boolean ENABLE_ANONYMOUS_SSL
System property h2.enableAnonymousSSL (default: true).
When using SSL connection, the anonymous cipher suite SSL_DH_anon_WITH_RC4_128_MD5 should be enabled.


BIND_ADDRESS

public static final java.lang.String BIND_ADDRESS
System property h2.bindAddress (default: *).
Comma separated list of class names or prefixes.


CACHE_SIZE_DEFAULT

public static final int CACHE_SIZE_DEFAULT
System property h2.cacheSizeDefault (default: 16384).
The default cache size in KB.


CACHE_SIZE_INDEX_SHIFT

public static final int CACHE_SIZE_INDEX_SHIFT
System property h2.cacheSizeIndexShift (default: 3).
How many time the cache size value is divided by two to get the index cache size. The index cache size is calculated like this: cacheSize >> cacheSizeIndexShift.


CACHE_SIZE_INDEX_DEFAULT

public static final int CACHE_SIZE_INDEX_DEFAULT
INTERNAL


CACHE_TYPE_DEFAULT

public static final java.lang.String CACHE_TYPE_DEFAULT
System property h2.cacheTypeDefault (default: LRU).
How many time the cache size value is divided by two to get the index cache size. The index cache size is calculated like this: cacheSize >> cacheSizeIndexShift.


CHECK

public static final boolean CHECK
System property h2.check (default: true).
Assertions in the database engine.


CHECK2

public static final boolean CHECK2
System property h2.check2 (default: true).
Additional assertions in the database engine.


CLIENT_TRACE_DIRECTORY

public static final java.lang.String CLIENT_TRACE_DIRECTORY
System property h2.clientTraceDirectory (default: trace.db/).
Directory where the trace files of the JDBC client are stored (only for client / server).


DEFAULT_ESCAPE_CHAR

public static final java.lang.Character DEFAULT_ESCAPE_CHAR
System property h2.defaultEscape (default: \).
The default escape character for LIKE comparisons. To select no escape character, use an empty string.


DEFAULT_MAX_OPERATION_MEMORY

public static final int DEFAULT_MAX_OPERATION_MEMORY
System property h2.defaultMaxOperationMemory (default: 100000).
The default for the setting MAX_OPERATION_MEMORY.


DEFAULT_MAX_LENGTH_INPLACE_LOB

public static final int DEFAULT_MAX_LENGTH_INPLACE_LOB
System property h2.defaultMaxLengthInplaceLob.
The default maximum length of an LOB that is stored in the data file itself.

In version 1.1, the default is 1024.

In version 1.2, the default is 4096.


DEFAULT_RESULT_SET_CONCURRENCY

public static final int DEFAULT_RESULT_SET_CONCURRENCY
System property h2.defaultResultSetConcurrency (default: ResultSet.CONCUR_READ_ONLY).
The default result set concurrency for statements created with Connection.createStatement() or prepareStatement(String sql).


DATASOURCE_TRACE_LEVEL

public static final int DATASOURCE_TRACE_LEVEL
System property h2.dataSourceTraceLevel (default: 1).
The trace level of the data source implementation. Default is 1 for error.


DEFAULT_MAX_MEMORY_UNDO

public static final int DEFAULT_MAX_MEMORY_UNDO
System property h2.defaultMaxMemoryUndo (default: 50000).
The default value for the MAX_MEMORY_UNDO setting.


DEFAULT_LOCK_MODE

public static final int DEFAULT_LOCK_MODE
System property h2.defaultLockMode (default: 3).
The default value for the LOCK_MODE setting.


DELAY_WRONG_PASSWORD_MIN

public static final int DELAY_WRONG_PASSWORD_MIN
System property h2.delayWrongPasswordMin (default: 250).
The minimum delay in milliseconds before an exception is thrown for using the wrong user name or password. This slows down brute force attacks. The delay is reset to this value after a successful login. Unsuccessful logins will double the time until DELAY_WRONG_PASSWORD_MAX.


DELAY_WRONG_PASSWORD_MAX

public static final int DELAY_WRONG_PASSWORD_MAX
System property h2.delayWrongPasswordMax (default: 4000).
The maximum delay in milliseconds before an exception is thrown for using the wrong user name or password. This slows down brute force attacks. The delay is reset after a successful login. The value 0 means there is no maximum delay.


DOLLAR_QUOTING

public static final boolean DOLLAR_QUOTING
System property h2.dollarQuoting (default: true).
Dollar quoting is used to quote text without having to use escape characters. A dollar quoted string starts and ends with $$. Inside the text, $$ is not allowed.


ESTIMATED_FUNCTION_TABLE_ROWS

public static final int ESTIMATED_FUNCTION_TABLE_ROWS
System property h2.estimatedFunctionTableRows (default: 1000).
The estimated number of rows in a function table (for example, CSVREAD or FTL_SEARCH). This value is used by the optimizer.


LARGE_RESULT_BUFFER_SIZE

public static final int LARGE_RESULT_BUFFER_SIZE
System property h2.largeResultBufferSize (default: 4096).
Buffer size for large result sets. Set this value to 0 to disable the buffer.


lobCloseBetweenReads

public static boolean lobCloseBetweenReads
System property h2.lobCloseBetweenReads (default: false).
Close LOB files between read operations.


LOB_FILES_IN_DIRECTORIES

public static final boolean LOB_FILES_IN_DIRECTORIES
System property h2.lobFilesInDirectories.
Store LOB files in subdirectories.

In version 1.0, it is disabled by default.

In version 1.1, it is enabled by default.


LOB_FILES_PER_DIRECTORY

public static final int LOB_FILES_PER_DIRECTORY
System property h2.lobFilesPerDirectory (default: 256).
Maximum number of LOB files per directory.


LOG_ALL_ERRORS

public static final boolean LOG_ALL_ERRORS
System property h2.logAllErrors (default: false).
Write stack traces of any kind of error to a file.


LOG_ALL_ERRORS_FILE

public static final java.lang.String LOG_ALL_ERRORS_FILE
System property h2.logAllErrorsFile (default: h2errors.txt).
File name to log errors.


MAX_FILE_RETRY

public static final int MAX_FILE_RETRY
System property h2.maxFileRetry (default: 16).
Number of times to retry file delete and rename. in Windows, files can't be deleted if they are open. Waiting a bit can help (sometimes the Windows Explorer opens the files for a short time) may help. Sometimes, running garbage collection may close files if the user forgot to call Connection.close() or InputStream.close().


MAX_MEMORY_ROWS_DISTINCT

public static final int MAX_MEMORY_ROWS_DISTINCT
System property h2.maxMemoryRowsDistinct (default: Integer.MAX_VALUE).
The maximum number of rows kept in-memory for SELECT DISTINCT queries. If more than this number of rows are in a result set, a temporary table is used.


MAX_QUERY_TIMEOUT

public static final int MAX_QUERY_TIMEOUT
System property h2.maxQueryTimeout (default: 0).
The maximum timeout of a query. The default is 0, meaning no limit.


MAX_RECONNECT

public static final int MAX_RECONNECT
System property h2.maxReconnect (default: 3).
The maximum number of tries to reconnect in a row.


MAX_TRACE_DATA_LENGTH

public static final long MAX_TRACE_DATA_LENGTH
System property h2.maxTraceDataLength (default: 65535).
The maximum size of a LOB value that is written as data to the trace system.


MIN_COLUMN_NAME_MAP

public static final int MIN_COLUMN_NAME_MAP
System property h2.minColumnNameMap (default: 3).
The minimum number of columns where a hash table is created when result set methods with column name (instead of column index) parameter are called.


MIN_WRITE_DELAY

public static final int MIN_WRITE_DELAY
System property h2.minWriteDelay (default: 5).
The minimum write delay that causes commits to be delayed.


NIO_LOAD_MAPPED

public static final boolean NIO_LOAD_MAPPED
System property h2.nioLoadMapped (default: false).
If the mapped buffer should be loaded when the file is opened. This can improve performance.


NIO_CLEANER_HACK

public static final boolean NIO_CLEANER_HACK
System property h2.nioCleanerHack (default: true).
If possible, use a hack to un-map the mapped file. See also http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038


NULL_CONCAT_IS_NULL

public static final boolean NULL_CONCAT_IS_NULL
System property h2.nullConcatIsNull.
Concatenation with NULL results in NULL. Usually, NULL is treated as an empty string if only one of the operands is NULL, and NULL is only returned if both operands are NULL.

In version 1.1, it is disabled by default.

In version 1.2, it is enabled by default.


OBJECT_CACHE

public static final boolean OBJECT_CACHE
System property h2.objectCache (default: true).
Cache commonly used objects (integers, strings).


OBJECT_CACHE_MAX_PER_ELEMENT_SIZE

public static final int OBJECT_CACHE_MAX_PER_ELEMENT_SIZE
System property h2.objectCacheMaxPerElementSize (default: 4096).
Maximum size of an object in the cache.


OBJECT_CACHE_SIZE

public static final int OBJECT_CACHE_SIZE
System property h2.objectCacheSize (default: 1024).
Maximum size of an object in the cache. This value must be a power of 2.


OLD_COMMAND_LINE_OPTIONS

public static final boolean OLD_COMMAND_LINE_OPTIONS
System property h2.oldCommandLineOptions.
Support old command line options.

In version 1.0, it is enabled by default.

In version 1.1, it is disabled by default.


OPTIMIZE_DROP_DEPENDENCIES

public static final boolean OPTIMIZE_DROP_DEPENDENCIES
System property h2.optimizeDropDependencies (default: true).
Improve the performance of DROP and DROP ALL OBJECTS by quicker scanning if other objects depend on this object.


OPTIMIZE_DISTINCT

public static final boolean OPTIMIZE_DISTINCT
System property h2.optimizeDistinct (default: true).
Improve the performance of simple DISTINCT queries if an index is available for the given column. The optimization is used if:


OPTIMIZE_EVALUATABLE_SUBQUERIES

public static final boolean OPTIMIZE_EVALUATABLE_SUBQUERIES
System property h2.optimizeEvaluatableSubqueries (default: true).
Optimize subqueries that are not dependent on the outer query.


OPTIMIZE_GROUP_SORTED

public static final boolean OPTIMIZE_GROUP_SORTED
System property h2.optimizeGroupSorted.
Optimize GROUP BY queries if an index can be used that matches the group by columns.

In version 1.0, it is disabled by default.

In version 1.1, it is enabled by default.


OPTIMIZE_IN

public static final boolean OPTIMIZE_IN
System property h2.optimizeIn (default: true).
Optimize IN(...) comparisons.


OPTIMIZE_IN_LIST

public static final boolean OPTIMIZE_IN_LIST
System property h2.optimizeInList (default: false).
Optimize IN(...) and IN(SELECT ...) comparisons. This includes optimization for SELECT, DELETE, and UPDATE. Overrides h2.optimizeIn and h2.optimizeInJoin if enabled.

In version 1.1, it is disabled by default.

In version 1.2, it is enabled by default.


optimizeInJoin

public static boolean optimizeInJoin
System property h2.optimizeInJoin (default: false).
Optimize IN(...) comparisons by converting them to inner joins.

In version 1.0, it is disabled by default.

In version 1.1, it is enabled by default.


OPTIMIZE_MIN_MAX

public static final boolean OPTIMIZE_MIN_MAX
System property h2.optimizeMinMax (default: true).
Optimize MIN and MAX aggregate functions.


OPTIMIZE_NOT

public static final boolean OPTIMIZE_NOT
System property h2.optimizeNot (default: true).
Optimize NOT conditions by removing the NOT and inverting the condition.


OPTIMIZE_OR

public static final boolean OPTIMIZE_OR
System property h2.optimizeOr (default: false).
Convert (C=? OR C=?) to (C IN(?, ?)).


OPTIMIZE_SUBQUERY_CACHE

public static final boolean OPTIMIZE_SUBQUERY_CACHE
System property h2.optimizeSubqueryCache (default: true).
Cache subquery results.


OPTIMIZE_TWO_EQUALS

public static final boolean OPTIMIZE_TWO_EQUALS
System property h2.optimizeTwoEquals (default: true).
Optimize expressions of the form A=B AND B=1. In this case, AND A=1 is added so an index on A can be used.


OVERFLOW_EXCEPTIONS

public static final boolean OVERFLOW_EXCEPTIONS
System property h2.overflowExceptions (default: true).
Throw an exception on integer overflows.


PAGE_STORE

public static final boolean PAGE_STORE
System property h2.pageStore.
Use the 'page store' database file format for new databases.

In version 1.1, it is disabled by default.

In version 1.2, it is enabled by default.


PG_DEFAULT_CLIENT_ENCODING

public static final java.lang.String PG_DEFAULT_CLIENT_ENCODING
System property h2.pgClientEncoding (default: UTF-8).
Default client encoding for PG server. It is used if the client does not sends his encoding.


RECOMPILE_ALWAYS

public static final boolean RECOMPILE_ALWAYS
System property h2.recompileAlways (default: false).
Always recompile prepared statements.


RECONNECT_CHECK_DELAY

public static final int RECONNECT_CHECK_DELAY
System property h2.reconnectCheckDelay (default: 200).
Check the .lock.db file every this many milliseconds to detect that the database was changed. The process writing to the database must first notify a change in the .lock.db file, then wait twice this many milliseconds before updating the database.


REDO_BUFFER_SIZE

public static final int REDO_BUFFER_SIZE
System property h2.redoBufferSize (default: 262144).
Size of the redo buffer (used at startup when recovering).


RESERVE_MEMORY

public static final int RESERVE_MEMORY
System property h2.reserveMemory (default: 524288).
This many bytes in main memory are allocated as a reserve. This reserve is freed up when if no memory is available, so that rolling back a large transaction is easier.


RETURN_LOB_OBJECTS

public static final boolean RETURN_LOB_OBJECTS
System property h2.returnLobObjects.
When true, ResultSet.getObject for CLOB or BLOB will return a java.sql.Clob / java.sql.Blob object. When set to false, it will return a java.io.Reader / java.io.InputStream.

In version 1.0, it is disabled by default.

In version 1.1, it is enabled by default.


REUSE_SPACE_AFTER

public static final int REUSE_SPACE_AFTER
System property h2.reuseSpaceAfter (default: 16).
Reuse space in database files after this many pages are free.


REUSE_SPACE_BTREE_INDEX

public static final boolean REUSE_SPACE_BTREE_INDEX
System property h2.reuseSpaceBtreeIndex (default: true).
Reuse space after deleting or updating many rows in a b-tree index.


REUSE_SPACE_QUICKLY

public static final boolean REUSE_SPACE_QUICKLY
System property h2.reuseSpaceQuickly (default: true).
Reuse space in database files quickly.


runFinalize

public static boolean runFinalize
System property h2.runFinalize (default: true).
Run finalizers to detect unclosed connections.


SERVER_CACHED_OBJECTS

public static final int SERVER_CACHED_OBJECTS
System property h2.serverCachedObjects (default: 64).
TCP Server: number of cached objects per session.


SERVER_RESULT_SET_FETCH_SIZE

public static final int SERVER_RESULT_SET_FETCH_SIZE
System property h2.serverResultSetFetchSize (default: 100).
The default result set fetch size when using the server mode.


SHARE_LINKED_CONNECTIONS

public static final boolean SHARE_LINKED_CONNECTIONS
System property h2.shareLinkedConnections.
Linked connections should be shared, that means connections to the same database should be used for all linked tables that connect to the same database.

In version 1.0, it is disabled by default.

In version 1.1, it is enabled by default.


SOCKET_CONNECT_TIMEOUT

public static final int SOCKET_CONNECT_TIMEOUT
System property h2.socketConnectTimeout (default: 2000).
The timeout in milliseconds to connect to a server.


SORT_NULLS_HIGH

public static final boolean SORT_NULLS_HIGH
System property h2.sortNullsHigh (default: false).
Invert the default sorting behavior for NULL values, such that NULL values are sorted to the end of a result set in an ascending sort and to the beginning of a result set in a descending sort.


SPLIT_FILE_SIZE_SHIFT

public static final long SPLIT_FILE_SIZE_SHIFT
System property h2.splitFileSizeShift (default: 30).
The maximum file size of a split file is 1L << x.


TRACE_IO

public static final boolean TRACE_IO
System property h2.traceIO (default: false).
Trace all I/O operations.


WEB_MAX_VALUE_LENGTH

public static final int WEB_MAX_VALUE_LENGTH
System property h2.webMaxValueLength (default: 10000).
The H2 Console will abbreviate result values larger than this size.


COLLATOR_CACHE_SIZE

public static final int COLLATOR_CACHE_SIZE
System property h2.collatorCacheSize (default: 10000).
The cache size for collation keys (in elements). Used when a collator has been set for the database.


TIME_START

public static final long TIME_START
The current time this class was loaded (in milliseconds).

Method Detail

getStringSetting

public static java.lang.String getStringSetting(java.lang.String name,
                                                java.lang.String defaultValue)
INTERNAL


getIntSetting

public static int getIntSetting(java.lang.String name,
                                int defaultValue)
INTERNAL


setBaseDir

public static void setBaseDir(java.lang.String dir)
INTERNAL


getBaseDir

public static java.lang.String getBaseDir()
INTERNAL


getScriptDirectory

public static java.lang.String getScriptDirectory()
INTERNAL. System property h2.scriptDirectory (default: empty string).
Relative or absolute directory where the script files are stored to or read from.


setScriptDirectory

public static void setScriptDirectory(java.lang.String dir)
INTERNAL


getMaxQueryTimeout

public static int getMaxQueryTimeout()
INTERNAL


getLogFileDeleteDelay

public static int getLogFileDeleteDelay()
INTERNAL


getCollatorCacheSize

public static int getCollatorCacheSize()
INTERNAL


getPageStore

public static boolean getPageStore()
INTERNAL