SysProperties

The 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=/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");


Methods
static String getScriptDirectory()
System property h2.scriptDirectory (default: empty string).
static String getScriptDirectory()
System property h2.scriptDirectory (default: empty string). Relative or absolute directory where the script files are stored to or read from.
Returns:
the current value

Fields
static String ALLOWED_CLASSES
static String AUTH_CONFIG_FILE
static String BIND_ADDRESS
static boolean CHECK
static String CLIENT_TRACE_DIRECTORY
static int COLLATOR_CACHE_SIZE
static int CONSOLE_MAX_PROCEDURES_LIST_COLUMNS
static int CONSOLE_MAX_TABLES_LIST_COLUMNS
static int CONSOLE_MAX_TABLES_LIST_INDEXES
static boolean CONSOLE_STREAM
static int CONSOLE_TIMEOUT
static int DATASOURCE_TRACE_LEVEL
static int DELAY_WRONG_PASSWORD_MAX
static int DELAY_WRONG_PASSWORD_MIN
static boolean ENABLE_ANONYMOUS_TLS
static boolean FORCE_AUTOCOMMIT_OFF_ON_COMMIT
static String JAVA_OBJECT_SERIALIZER
static boolean JAVA_SYSTEM_COMPILER
static int LOB_CLIENT_MAX_SIZE_MEMORY
static int MAX_FILE_RETRY
static int MAX_MEMORY_ROWS
static int MAX_RECONNECT
static long MAX_TRACE_DATA_LENGTH
static boolean NIO_CLEANER_HACK
static boolean NIO_LOAD_MAPPED
static boolean OBJECT_CACHE
static int OBJECT_CACHE_MAX_PER_ELEMENT_SIZE
static int OBJECT_CACHE_SIZE
static String PG_DEFAULT_CLIENT_ENCODING
static String PREFIX_TEMP_FILE
static int SERVER_CACHED_OBJECTS
static int SERVER_RESULT_SET_FETCH_SIZE
static int SOCKET_CONNECT_RETRY
static int SOCKET_CONNECT_TIMEOUT
static long SPLIT_FILE_SIZE_SHIFT
static boolean THREAD_DEADLOCK_DETECTOR
static boolean TRACE_IO
static String URL_MAP
static String USER_HOME
static boolean USE_THREAD_CONTEXT_CLASS_LOADER
static boolean lobCloseBetweenReads

ALLOWED_CLASSES

System property h2.allowedClasses (default: *). Comma separated list of class names or prefixes.

AUTH_CONFIG_FILE

System property h2.authConfigFile (default: null). authConfigFile define the URL of configuration file of {@link org.h2.security.auth.DefaultAuthenticator}

BIND_ADDRESS

System property h2.bindAddress (default: null). The bind address to use.

CHECK

System property h2.check (default: true for JDK/JRE, false for Android). Optional additional checks in the database engine.

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).

COLLATOR_CACHE_SIZE

System property h2.collatorCacheSize (default: 3 2000). The cache size for collation keys (in elements). Used when a collator has been set for the database.

CONSOLE_MAX_PROCEDURES_LIST_COLUMNS

System property h2.consoleProcedureColumns (default: 500). Up to this many procedures, the column names are listed.

CONSOLE_MAX_TABLES_LIST_COLUMNS

System property h2.consoleTableColumns (default: 500). Up to this many tables, the column names are listed.

CONSOLE_MAX_TABLES_LIST_INDEXES

System property h2.consoleTableIndexes (default: 100). Up to this many tables, the column type and indexes are listed.

CONSOLE_STREAM

System property h2.consoleStream (default: true). H2 Console: stream query results.

CONSOLE_TIMEOUT

System property h2.consoleTimeout (default: 1800000). H2 Console: session timeout in milliseconds. The default is 30 minutes.

DATASOURCE_TRACE_LEVEL

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

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.

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. To disable the delay, set this system property to 0.

ENABLE_ANONYMOUS_TLS

System property h2.enableAnonymousTLS (default: true). When using TLS connection, the anonymous cipher suites should be enabled.

FORCE_AUTOCOMMIT_OFF_ON_COMMIT

System property h2.forceAutoCommitOffOnCommit (default: false). Throw error if transaction's auto-commit property is true when a commit is executed.

JAVA_OBJECT_SERIALIZER

System 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_SYSTEM_COMPILER

System 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.

LOB_CLIENT_MAX_SIZE_MEMORY

System 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.

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

System property h2.maxMemoryRows (default: 40000 per GB of available RAM). The default maximum number of rows to be kept in memory in a result set.

MAX_RECONNECT

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

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.

NIO_CLEANER_HACK

System 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 https://bugs.openjdk.java.net/browse/JDK-4724038

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.

OBJECT_CACHE

System property h2.objectCache (default: true). Cache commonly used values (numbers, strings). There is a shared cache for all values.

OBJECT_CACHE_MAX_PER_ELEMENT_SIZE

System property h2.objectCacheMaxPerElementSize (default: 4096). The maximum size (precision) of an object in the cache.

OBJECT_CACHE_SIZE

System property h2.objectCacheSize (default: 1024). The maximum number of objects in the cache. This value must be a power of 2.

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.

PREFIX_TEMP_FILE

System property h2.prefixTempFile (default: h2.temp). The prefix for temporary files in the temp directory.

SERVER_CACHED_OBJECTS

System property h2.serverCachedObjects (default: 64). TCP Server: number of cached objects per session.

SERVER_RESULT_SET_FETCH_SIZE

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

SOCKET_CONNECT_RETRY

System property h2.socketConnectRetry (default: 16). The number of times to retry opening a socket. Windows sometimes fails to open a socket, see bug https://bugs.openjdk.java.net/browse/JDK-6213296

SOCKET_CONNECT_TIMEOUT

System property h2.socketConnectTimeout (default: 2000). The timeout in milliseconds to connect to a server.

SPLIT_FILE_SIZE_SHIFT

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

THREAD_DEADLOCK_DETECTOR

System property h2.threadDeadlockDetector (default: false). Detect thread deadlocks in a background thread.

TRACE_IO

System property h2.traceIO (default: false). Trace all I/O operations.

URL_MAP

System 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_HOME

System 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_LOADER

System property h2.useThreadContextClassLoader (default: false). Instead of using the default class loader when deserializing objects, the current thread-context class loader will be used.

lobCloseBetweenReads

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