Package org.h2.engine

Class SysProperties

java.lang.Object
org.h2.engine.SysProperties
public class SysProperties extends Object
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");

  • Field Details

    • H2_SCRIPT_DIRECTORY

      public static final String H2_SCRIPT_DIRECTORY
      INTERNAL
      See Also:

    • H2_BROWSER

      public static final String H2_BROWSER
      INTERNAL
      See Also:

    • USER_HOME

      public static final String 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.

    • ALLOWED_CLASSES

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

    • BIND_ADDRESS

      public static final String BIND_ADDRESS
      System property h2.bindAddress (default: null). The bind address to use.

    • CHECK

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

    • CLIENT_TRACE_DIRECTORY

      public static final 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).

    • COLLATOR_CACHE_SIZE

      public static final int 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_TABLES_LIST_INDEXES

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

    • CONSOLE_MAX_TABLES_LIST_COLUMNS

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

    • CONSOLE_MAX_PROCEDURES_LIST_COLUMNS

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

    • CONSOLE_STREAM

      public static final boolean CONSOLE_STREAM
      System property h2.consoleStream (default: true). H2 Console: stream query results.

    • CONSOLE_TIMEOUT

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

    • 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.

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

    • 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.

    • JAVA_SYSTEM_COMPILER

      public static final boolean 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.

    • lobCloseBetweenReads

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

    • LOB_CLIENT_MAX_SIZE_MEMORY

      public static final int 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

      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_RECONNECT

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

    • MAX_MEMORY_ROWS

      public static final int 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_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.

    • 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: 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

    • OBJECT_CACHE

      public static final boolean 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

      public static final int 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

      public static final int 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

      public static final 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.

    • PREFIX_TEMP_FILE

      public static final String PREFIX_TEMP_FILE
      System property h2.prefixTempFile (default: h2.temp). The prefix for temporary files in the temp directory.

    • FORCE_AUTOCOMMIT_OFF_ON_COMMIT

      public static boolean 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.

    • 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.

    • SOCKET_CONNECT_RETRY

      public static final int 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

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

    • 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.

    • THREAD_DEADLOCK_DETECTOR

      public static final boolean THREAD_DEADLOCK_DETECTOR
      System property h2.threadDeadlockDetector (default: false). Detect thread deadlocks in a background thread.

    • URL_MAP

      public static final String 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.

    • USE_THREAD_CONTEXT_CLASS_LOADER

      public static final boolean 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.

    • JAVA_OBJECT_SERIALIZER

      public static final String 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.

    • AUTH_CONFIG_FILE

      public static final String AUTH_CONFIG_FILE
      System property h2.authConfigFile (default: null). authConfigFile define the URL of configuration file of DefaultAuthenticator

  • Method Details

    • setBaseDir

      public static void setBaseDir(String dir)
      INTERNAL
      Parameters:
      dir - base directory

    • getBaseDir

      public static String getBaseDir()
      INTERNAL
      Returns:
      base directory

    • getScriptDirectory

      public 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