SysPropertiesThe constants defined in this class are initialized from system properties. Some system properties are per machine settings, and others are as a last resort and temporary solution to work around a problem in the application or database engine. Also, there are system properties to enable features that are not yet fully tested or that are not backward compatible.System properties can be set when starting the virtual machine: java -Dh2.baseDir=/tempThey 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");
ALLOWED_CLASSESSystem property
h2.allowedClasses (default: *).Comma separated list of class names or prefixes. BIND_ADDRESSSystem property
h2.bindAddress (default: null).The bind address to use. BROWSERSystem 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" ... .CHECKSystem property
h2.check (default: true).Assertions in the database engine. CHECK2System property
h2.check2 (default: true).Additional assertions in the database engine. CLIENT_TRACE_DIRECTORYSystem property
h2.clientTraceDirectory (default:
trace.db/).Directory where the trace files of the JDBC client are stored (only for client / server). COLLATOR_CACHE_SIZESystem property
h2.collatorCacheSize (default: 32000).The cache size for collation keys (in elements). Used when a collator has been set for the database. CONSOLE_STREAMSystem property
h2.consoleStream (default: true).H2 Console: stream query results. CONSOLE_TIMEOUTSystem property
h2.consoleTimeout (default: 1800000).H2 Console: session timeout in milliseconds. The default is 30 minutes. DATASOURCE_TRACE_LEVELSystem property
h2.dataSourceTraceLevel (default: 1).The trace level of the data source implementation. Default is 1 for error. DELAY_WRONG_PASSWORD_MAXSystem 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. DELAY_WRONG_PASSWORD_MINSystem 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. To disable the delay, set this system property to 0. ENABLE_ANONYMOUS_SSLSystem property
h2.enableAnonymousSSL (default: true).When using SSL connection, the anonymous cipher suite SSL_DH_anon_WITH_RC4_128_MD5 should be enabled. FILE_ENCODINGSystem 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_SEPARATORSystem property
file.separator (default: /).It is usually set by the system, and used to build absolute file names. IMPLICIT_RELATIVE_PATHSystem property
h2.implicitRelativePath
(default: true for version 1.3, false for version 1.4).If disabled, relative paths in database URLs need to be written as jdbc:h2:./test instead of jdbc:h2:test. JAVA_OBJECT_SERIALIZERSystem property
h2.javaObjectSerializer
(default: null).The JavaObjectSerializer class name for java objects being stored in column of type OTHER. It must be the same on client and server to work correctly. JAVA_SPECIFICATION_VERSIONSystem property
java.specification.version .It is set by the system. Examples: 1.4, 1.5, 1.6. JAVA_SYSTEM_COMPILERSystem property
h2.javaSystemCompiler (default: true).Whether to use the Java system compiler (ToolProvider.getSystemJavaCompiler()) if it is available to compile user defined functions. If disabled or if the system compiler is not available, the com.sun.tools.javac compiler is used if available, and "javac" (as an external process) is used if not. LINE_SEPARATORSystem property
line.separator (default: \n).It is usually set by the system, and used by the script and trace tools. LOB_CLIENT_MAX_SIZE_MEMORYSystem property
h2.lobClientMaxSizeMemory (default:
1048576).The maximum size of a LOB object to keep in memory on the client side when using the server mode. LOB_FILES_PER_DIRECTORYSystem property
h2.lobFilesPerDirectory
(default: 256).Maximum number of LOB files per directory. MAX_FILE_RETRYSystem 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_RECONNECTSystem property
h2.maxReconnect (default: 3).The maximum number of tries to reconnect in a row. MAX_TRACE_DATA_LENGTHSystem property
h2.maxTraceDataLength
(default: 65535).The maximum size of a LOB value that is written as data to the trace system. MODIFY_ON_WRITESystem property
h2.modifyOnWrite (default: false).Only modify the database file when recovery is necessary, or when writing to the database. If disabled, opening the database always writes to the file (except if the database is read-only). When enabled, the serialized file lock is faster. NIO_CLEANER_HACKSystem property
h2.nioCleanerHack (default: false).If enabled, use the reflection hack to un-map the mapped file if possible. If disabled, System.gc() is called in a loop until the object is garbage collected. See also http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038 NIO_LOAD_MAPPEDSystem property
h2.nioLoadMapped (default: false).If the mapped buffer should be loaded when the file is opened. This can improve performance. OBJECT_CACHESystem property
h2.objectCache (default: true).Cache commonly used values (numbers, strings). There is a shared cache for all values. OBJECT_CACHE_MAX_PER_ELEMENT_SIZESystem property
h2.objectCacheMaxPerElementSize (default:
4096).The maximum size (precision) of an object in the cache. OBJECT_CACHE_SIZESystem property
h2.objectCacheSize (default: 1024).The maximum number of objects in the cache. This value must be a power of 2. OLD_STYLE_OUTER_JOINSystem property
h2.oldStyleOuterJoin
(default: true for version 1.3, false for version 1.4).Limited support for the old-style Oracle outer join with "(+)". PG_DEFAULT_CLIENT_ENCODINGSystem property
h2.pgClientEncoding (default: UTF-8).Default client encoding for PG server. It is used if the client does not sends his encoding. PREFIX_TEMP_FILESystem property
h2.prefixTempFile (default: h2.temp).The prefix for temporary files in the temp directory. SERVER_CACHED_OBJECTSSystem property
h2.serverCachedObjects (default: 64).TCP Server: number of cached objects per session. SERVER_RESULT_SET_FETCH_SIZESystem property
h2.serverResultSetFetchSize
(default: 100).The default result set fetch size when using the server mode. SOCKET_CONNECT_RETRYSystem property
h2.socketConnectRetry (default: 16).The number of times to retry opening a socket. Windows sometimes fails to open a socket, see bug http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6213296 SOCKET_CONNECT_TIMEOUTSystem property
h2.socketConnectTimeout
(default: 2000).The timeout in milliseconds to connect to a server. SORT_BINARY_UNSIGNEDSystem property
h2.sortBinaryUnsigned
(default: false with version 1.3, true with version 1.4).Whether binary data should be sorted in unsigned mode (0xff is larger than 0x00). SORT_NULLS_HIGHSystem property
h2.sortNullsHigh (default: false).Invert the default sorting behavior for NULL, such that NULL is at the end of a result set in an ascending sort and at the beginning of a result set in a descending sort. SPLIT_FILE_SIZE_SHIFTSystem property
h2.splitFileSizeShift (default: 30).The maximum file size of a split file is 1L << x. STORE_LOCAL_TIMESystem property
h2.storeLocalTime
(default: false for version 1.3, true for version 1.4).Store the local time. If disabled, the daylight saving offset is not taken into account. SYNC_METHODSystem property
h2.syncMethod (default: sync).What method to call when closing the database, on checkpoint, and on CHECKPOINT SYNC. The following options are supported: "sync" (default): RandomAccessFile.getFD().sync(); "force": RandomAccessFile.getChannel().force(true); "forceFalse": RandomAccessFile.getChannel().force(false); "": do not call a method (fast but there is a risk of data loss on power failure). TRACE_IOSystem property
h2.traceIO (default: false).Trace all I/O operations. URL_MAPSystem property
h2.urlMap (default: null).A properties file that contains a mapping between database URLs. New connections are written into the file. An empty value in the map means no redirection is used for the given URL. USER_HOMESystem property
user.home (empty string if not set).It is usually set by the system, and used as a replacement for ~ in file names. USE_THREAD_CONTEXT_CLASS_LOADERSystem property
h2.useThreadContextClassLoader
(default: false).Instead of using the default class loader when deserializing objects, the current thread-context class loader will be used. lobCloseBetweenReadsSystem property
h2.lobCloseBetweenReads
(default: false).Close LOB files between read operations. serializeJavaObjectSystem property
h2.serializeJavaObject
(default: true).If true, values of type OTHER will be stored in serialized form and have the semantics of binary data for all operations (such as sorting and conversion to string). If false, the objects will be serialized only for I/O operations and a few other special cases (for example when someone tries to get the value in binary form or when comparing objects that are not comparable otherwise). If the object implements the Comparable interface, the method compareTo will be used for sorting (but only if objects being compared have a common comparable super type). Otherwise the objects will be compared by type, and if they are the same by hashCode, and if the hash codes are equal, but objects are not, the serialized forms (the byte arrays) are compared. The string representation of the values use the toString method of object. In client-server mode, the server must have all required classes in the class path. On the client side, this setting is required to be disabled as well, to have correct string representation and display size. In embedded mode, no data copying occurs, so the user has to make defensive copy himself before storing, or ensure that the value object is immutable. |