com.h2database/h2/1.4.199 : org/h2/engine/SysProperties.java

SysProperties
http://www.h2database.com: H2 Database Engine
MPL 2.0 or EPL 1.0
Thomas Mueller
/*
 * Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
 * and the EPL 1.0 (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.engine;

import java.io.File;

import org.h2.util.MathUtils;
import org.h2.util.Utils;

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");

/**
 * 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.
 * <p>
 * System properties can be set when starting the virtual machine:
 * </p>
 *
 * <pre>
 * java -Dh2.baseDir=/temp
 * </pre>
 *
 * They can be set within the application, but this must be done before loading
 * any classes of this database (before loading the JDBC driver):
 *
 * <pre>
 * System.setProperty(&quot;h2.baseDir&quot;, &quot;/temp&quot;);
 * </pre>
 */
public class SysProperties {

    INTERNAL
/**
     * INTERNAL
     */
    public static final String H2_SCRIPT_DIRECTORY = "h2.scriptDirectory";

    INTERNAL
/**
     * INTERNAL
     */
    public static final String H2_BROWSER = "h2.browser";

    System property file.separator.

It is set by the system, and used to build absolute file names.
/**
     * System property <code>file.separator</code>.<br />
     * It is set by the system, and used to build absolute file names.
     */
    public static final String FILE_SEPARATOR = File.separator;

    System property line.separator.

It is set by the system, and used by the script and trace tools.
/**
     * System property <code>line.separator</code>.<br />
     * It is set by the system, and used by the script and trace tools.
     */
    public static final String LINE_SEPARATOR = System.lineSeparator();

    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.
/**
     * System property <code>user.home</code> (empty string if not set).<br />
     * It is usually set by the system, and used as a replacement for ~ in file
     * names.
     */
    public static final String USER_HOME =
            Utils.getProperty("user.home", "");

    System property h2.preview (default: false).  Controls default values of other properties. If true default values of other properties are changed to planned defaults for the 1.5.x versions of H2. Some other functionality may be also enabled or disabled. 
/**
     * System property {@code h2.preview} (default: false).
     * <p>
     * Controls default values of other properties. If {@code true} default
     * values of other properties are changed to planned defaults for the 1.5.x
     * versions of H2. Some other functionality may be also enabled or disabled.
     * </p>
     */
    public static final boolean PREVIEW = Utils.getProperty("h2.preview", false);

    System property h2.allowedClasses (default: *).

Comma separated list of class names or prefixes.
/**
     * System property <code>h2.allowedClasses</code> (default: *).<br />
     * Comma separated list of class names or prefixes.
     */
    public static final String ALLOWED_CLASSES =
            Utils.getProperty("h2.allowedClasses", "*");

    System property h2.enableAnonymousTLS (default: true).

When using TLS connection, the anonymous cipher suites should be enabled.
/**
     * System property <code>h2.enableAnonymousTLS</code> (default: true).<br />
     * When using TLS connection, the anonymous cipher suites should be enabled.
     */
    public static final boolean ENABLE_ANONYMOUS_TLS =
            Utils.getProperty("h2.enableAnonymousTLS", true);

    System property h2.bindAddress (default: null).

The bind address to use.
/**
     * System property <code>h2.bindAddress</code> (default: null).<br />
     * The bind address to use.
     */
    public static final String BIND_ADDRESS =
            Utils.getProperty("h2.bindAddress", null);

    System property h2.check
(default: true for JDK/JRE, false for Android).

Optional additional checks in the database engine.
/**
     * System property <code>h2.check</code>
     * (default: true for JDK/JRE, false for Android).<br />
     * Optional additional checks in the database engine.
     */
    public static final boolean CHECK =
            Utils.getProperty("h2.check", !"0.9".equals(Utils.getProperty("java.specification.version", null)));

    System property h2.clientTraceDirectory (default:
trace.db/).

Directory where the trace files of the JDBC client are stored (only for
client / server).
/**
     * System property <code>h2.clientTraceDirectory</code> (default:
     * trace.db/).<br />
     * Directory where the trace files of the JDBC client are stored (only for
     * client / server).
     */
    public static final String CLIENT_TRACE_DIRECTORY =
            Utils.getProperty("h2.clientTraceDirectory", "trace.db/");

    System property h2.collatorCacheSize (default: 32000).

The cache size for collation keys (in elements). Used when a collator has
been set for the database.
/**
     * System property <code>h2.collatorCacheSize</code> (default: 32000).<br />
     * The cache size for collation keys (in elements). Used when a collator has
     * been set for the database.
     */
    public static final int COLLATOR_CACHE_SIZE =
            Utils.getProperty("h2.collatorCacheSize", 32_000);

    System property h2.consoleTableIndexes
(default: 100).

Up to this many tables, the column type and indexes are listed.
/**
     * System property <code>h2.consoleTableIndexes</code>
     * (default: 100).<br />
     * Up to this many tables, the column type and indexes are listed.
     */
    public static final int CONSOLE_MAX_TABLES_LIST_INDEXES =
            Utils.getProperty("h2.consoleTableIndexes", 100);

    System property h2.consoleTableColumns
(default: 500).

Up to this many tables, the column names are listed.
/**
     * System property <code>h2.consoleTableColumns</code>
     * (default: 500).<br />
     * Up to this many tables, the column names are listed.
     */
    public static final int CONSOLE_MAX_TABLES_LIST_COLUMNS =
            Utils.getProperty("h2.consoleTableColumns", 500);

    System property h2.consoleProcedureColumns
(default: 500).

Up to this many procedures, the column names are listed.
/**
     * System property <code>h2.consoleProcedureColumns</code>
     * (default: 500).<br />
     * Up to this many procedures, the column names are listed.
     */
    public static final int CONSOLE_MAX_PROCEDURES_LIST_COLUMNS =
            Utils.getProperty("h2.consoleProcedureColumns", 300);

    System property h2.consoleStream (default: true).

H2 Console: stream query results.
/**
     * System property <code>h2.consoleStream</code> (default: true).<br />
     * H2 Console: stream query results.
     */
    public static final boolean CONSOLE_STREAM =
            Utils.getProperty("h2.consoleStream", true);

    System property h2.consoleTimeout (default: 1800000).

H2 Console: session timeout in milliseconds. The default is 30 minutes.
/**
     * System property <code>h2.consoleTimeout</code> (default: 1800000).<br />
     * H2 Console: session timeout in milliseconds. The default is 30 minutes.
     */
    public static final int CONSOLE_TIMEOUT =
            Utils.getProperty("h2.consoleTimeout", 30 * 60 * 1000);

    System property h2.dataSourceTraceLevel (default: 1).

The trace level of the data source implementation. Default is 1 for
error.
/**
     * System property <code>h2.dataSourceTraceLevel</code> (default: 1).<br />
     * The trace level of the data source implementation. Default is 1 for
     * error.
     */
    public static final int DATASOURCE_TRACE_LEVEL =
            Utils.getProperty("h2.dataSourceTraceLevel", 1);

    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.
/**
     * System property <code>h2.delayWrongPasswordMin</code>
     * (default: 250).<br />
     * 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.
     */
    public static final int DELAY_WRONG_PASSWORD_MIN =
            Utils.getProperty("h2.delayWrongPasswordMin", 250);

    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.
/**
     * System property <code>h2.delayWrongPasswordMax</code>
     * (default: 4000).<br />
     * 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.
     */
    public static final int DELAY_WRONG_PASSWORD_MAX =
            Utils.getProperty("h2.delayWrongPasswordMax", 4000);

    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.
/**
     * System property <code>h2.javaSystemCompiler</code> (default: true).<br />
     * 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.
     */
    public static final boolean JAVA_SYSTEM_COMPILER =
            Utils.getProperty("h2.javaSystemCompiler", true);

    System property h2.lobCloseBetweenReads
(default: false).

Close LOB files between read operations.
/**
     * System property <code>h2.lobCloseBetweenReads</code>
     * (default: false).<br />
     * Close LOB files between read operations.
     */
    public static boolean lobCloseBetweenReads =
            Utils.getProperty("h2.lobCloseBetweenReads", false);

    System property h2.lobFilesPerDirectory
(default: 256).

Maximum number of LOB files per directory.
/**
     * System property <code>h2.lobFilesPerDirectory</code>
     * (default: 256).<br />
     * Maximum number of LOB files per directory.
     */
    public static final int LOB_FILES_PER_DIRECTORY =
            Utils.getProperty("h2.lobFilesPerDirectory", 256);

    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.
/**
     * System property <code>h2.lobClientMaxSizeMemory</code> (default:
     * 1048576).<br />
     * The maximum size of a LOB object to keep in memory on the client side
     * when using the server mode.
     */
    public static final int LOB_CLIENT_MAX_SIZE_MEMORY =
            Utils.getProperty("h2.lobClientMaxSizeMemory", 1024 * 1024);

    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().
/**
     * System property <code>h2.maxFileRetry</code> (default: 16).<br />
     * 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().
     */
    public static final int MAX_FILE_RETRY =
            Math.max(1, Utils.getProperty("h2.maxFileRetry", 16));

    System property h2.maxReconnect (default: 3).

The maximum number of tries to reconnect in a row.
/**
     * System property <code>h2.maxReconnect</code> (default: 3).<br />
     * The maximum number of tries to reconnect in a row.
     */
    public static final int MAX_RECONNECT =
            Utils.getProperty("h2.maxReconnect", 3);

    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.
/**
     * System property <code>h2.maxMemoryRows</code>
     * (default: 40000 per GB of available RAM).<br />
     * The default maximum number of rows to be kept in memory in a result set.
     */
    public static final int MAX_MEMORY_ROWS =
            getAutoScaledForMemoryProperty("h2.maxMemoryRows", 40_000);

    System property h2.maxTraceDataLength
(default: 65535).

The maximum size of a LOB value that is written as data to the trace
system.
/**
     * System property <code>h2.maxTraceDataLength</code>
     * (default: 65535).<br />
     * The maximum size of a LOB value that is written as data to the trace
     * system.
     */
    public static final long MAX_TRACE_DATA_LENGTH =
            Utils.getProperty("h2.maxTraceDataLength", 65535);

    System 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.
/**
     * System property <code>h2.modifyOnWrite</code> (default: false).<br />
     * 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.
     */
    public static final boolean MODIFY_ON_WRITE =
            Utils.getProperty("h2.modifyOnWrite", false);

    System property h2.nioLoadMapped (default: false).

If the mapped buffer should be loaded when the file is opened.
This can improve performance.
/**
     * System property <code>h2.nioLoadMapped</code> (default: false).<br />
     * If the mapped buffer should be loaded when the file is opened.
     * This can improve performance.
     */
    public static final boolean NIO_LOAD_MAPPED =
            Utils.getProperty("h2.nioLoadMapped", false);

    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
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038
/**
     * System property <code>h2.nioCleanerHack</code> (default: false).<br />
     * 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
     */
    public static final boolean NIO_CLEANER_HACK =
            Utils.getProperty("h2.nioCleanerHack", false);

    System property h2.objectCache (default: true).

Cache commonly used values (numbers, strings). There is a shared cache
for all values.
/**
     * System property <code>h2.objectCache</code> (default: true).<br />
     * Cache commonly used values (numbers, strings). There is a shared cache
     * for all values.
     */
    public static final boolean OBJECT_CACHE =
            Utils.getProperty("h2.objectCache", true);

    System property h2.objectCacheMaxPerElementSize (default:
4096).

The maximum size (precision) of an object in the cache.
/**
     * System property <code>h2.objectCacheMaxPerElementSize</code> (default:
     * 4096).<br />
     * The maximum size (precision) of an object in the cache.
     */
    public static final int OBJECT_CACHE_MAX_PER_ELEMENT_SIZE =
            Utils.getProperty("h2.objectCacheMaxPerElementSize", 4096);

    System property h2.objectCacheSize (default: 1024).

The maximum number of objects in the cache.
This value must be a power of 2.
/**
     * System property <code>h2.objectCacheSize</code> (default: 1024).<br />
     * The maximum number of objects in the cache.
     * This value must be a power of 2.
     */
    public static final int OBJECT_CACHE_SIZE;
    static {
        try {
            OBJECT_CACHE_SIZE = MathUtils.nextPowerOf2(
                    Utils.getProperty("h2.objectCacheSize", 1024));
        } catch (IllegalArgumentException e) {
            throw new IllegalStateException("Invalid h2.objectCacheSize", e);
        }
    }

    System property h2.oldResultSetGetObject, true by default unless h2.preview is enabled.  If true return Byte and Short from ResultSet#getObject(int) and ResultSet#getObject(String) for TINYINT and SMALLINT values. 
 If false return Integer for them as specified in JDBC specification (see Mapping from JDBC Types to Java Object Types). 
/**
     * System property {@code h2.oldResultSetGetObject}, {@code true} by default
     * unless {@code h2.preview} is enabled.
     * <p>
     * If {@code true} return {@code Byte} and {@code Short} from
     * {@code ResultSet#getObject(int)} and {@code ResultSet#getObject(String)}
     * for {@code TINYINT} and {@code SMALLINT} values.
     * </p>
     * <p>
     * If {@code false} return {@code Integer} for them as specified in JDBC
     * specification (see Mapping from JDBC Types to Java Object Types).
     * </p>
     */
    public static final boolean OLD_RESULT_SET_GET_OBJECT = Utils.getProperty("h2.oldResultSetGetObject", !PREVIEW);

    System property h2.bigDecimalIsDecimal, true by default unless h2.preview is enabled.  If true map BigDecimal to DECIMAL type. 
 If false map BigDecimal to NUMERIC as specified in JDBC specification (see Mapping from Java Object Types to JDBC Types). 
/**
     * System property {@code h2.bigDecimalIsDecimal}, {@code true} by default
     * unless {@code h2.preview} is enabled.
     * <p>
     * If {@code true} map {@code BigDecimal} to {@code DECIMAL} type.
     * </p>
     * <p>
     * If {@code false} map {@code BigDecimal} to {@code NUMERIC} as specified
     * in JDBC specification (see Mapping from Java Object Types to JDBC Types).
     * </p>
     */
    public static final boolean BIG_DECIMAL_IS_DECIMAL = Utils.getProperty("h2.bigDecimalIsDecimal", !PREVIEW);

    System property h2.returnOffsetDateTime, false by default unless h2.preview is enabled.  If true ResultSet.getObject(int) and ResultSet.getObject(String) return TIMESTAMP WITH TIME ZONE values as java.time.OffsetDateTime. 
 If false return them as org.h2.api.TimestampWithTimeZone instead. 
 This property has effect only on Java 8 / Android API 26 and later versions. Without JSR-310 org.h2.api.TimestampWithTimeZone is used unconditionally. 
/**
     * System property {@code h2.returnOffsetDateTime}, {@code false} by default
     * unless {@code h2.preview} is enabled.
     * <p>
     * If {@code true} {@link java.sql.ResultSet#getObject(int)} and
     * {@link java.sql.ResultSet#getObject(String)} return
     * {@code TIMESTAMP WITH TIME ZONE} values as
     * {@code java.time.OffsetDateTime}.
     * </p>
     * <p>
     * If {@code false} return them as {@code org.h2.api.TimestampWithTimeZone}
     * instead.
     * </p>
     * <p>
     * This property has effect only on Java 8 / Android API 26 and later
     * versions. Without JSR-310 {@code org.h2.api.TimestampWithTimeZone} is
     * used unconditionally.
     * </p>
     */
    public static final boolean RETURN_OFFSET_DATE_TIME = Utils.getProperty("h2.returnOffsetDateTime", PREVIEW);

    System property h2.pgClientEncoding (default: UTF-8).

Default client encoding for PG server. It is used if the client does not
sends his encoding.
/**
     * System property <code>h2.pgClientEncoding</code> (default: UTF-8).<br />
     * Default client encoding for PG server. It is used if the client does not
     * sends his encoding.
     */
    public static final String PG_DEFAULT_CLIENT_ENCODING =
            Utils.getProperty("h2.pgClientEncoding", "UTF-8");

    System property h2.prefixTempFile (default: h2.temp).

The prefix for temporary files in the temp directory.
/**
     * System property <code>h2.prefixTempFile</code> (default: h2.temp).<br />
     * The prefix for temporary files in the temp directory.
     */
    public static final String PREFIX_TEMP_FILE =
            Utils.getProperty("h2.prefixTempFile", "h2.temp");

    System property h2.serverCachedObjects (default: 64).

TCP Server: number of cached objects per session.
/**
     * System property <code>h2.serverCachedObjects</code> (default: 64).<br />
     * TCP Server: number of cached objects per session.
     */
    public static final int SERVER_CACHED_OBJECTS =
            Utils.getProperty("h2.serverCachedObjects", 64);

    System property h2.serverResultSetFetchSize
(default: 100).

The default result set fetch size when using the server mode.
/**
     * System property <code>h2.serverResultSetFetchSize</code>
     * (default: 100).<br />
     * The default result set fetch size when using the server mode.
     */
    public static final int SERVER_RESULT_SET_FETCH_SIZE =
            Utils.getProperty("h2.serverResultSetFetchSize", 100);

    System 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
/**
     * System property <code>h2.socketConnectRetry</code> (default: 16).<br />
     * 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
     */
    public static final int SOCKET_CONNECT_RETRY =
            Utils.getProperty("h2.socketConnectRetry", 16);

    System property h2.socketConnectTimeout
(default: 2000).

The timeout in milliseconds to connect to a server.
/**
     * System property <code>h2.socketConnectTimeout</code>
     * (default: 2000).<br />
     * The timeout in milliseconds to connect to a server.
     */
    public static final int SOCKET_CONNECT_TIMEOUT =
            Utils.getProperty("h2.socketConnectTimeout", 2000);

    System property h2.sortBinaryUnsigned
(default: true).

Whether binary data should be sorted in unsigned mode
(0xff is larger than 0x00) by default in new databases.
/**
     * System property <code>h2.sortBinaryUnsigned</code>
     * (default: true).<br />
     * Whether binary data should be sorted in unsigned mode
     * (0xff is larger than 0x00) by default in new databases.
     */
    public static final boolean SORT_BINARY_UNSIGNED =
            Utils.getProperty("h2.sortBinaryUnsigned", true);

    System property h2.sortUuidUnsigned, false by default unless h2.preview is enabled. Whether UUID data should be sorted in unsigned mode ('ffffffff-ffff-ffff-ffff-ffffffffffff' is larger than '00000000-0000-0000-0000-000000000000') by default in new databases. /**
     * System property {@code h2.sortUuidUnsigned}, {@code false} by default
     * unless {@code h2.preview} is enabled.
     * Whether UUID data should be sorted in unsigned mode
     * ('ffffffff-ffff-ffff-ffff-ffffffffffff' is larger than
     * '00000000-0000-0000-0000-000000000000') by default in new databases.
     */
    public static final boolean SORT_UUID_UNSIGNED =
            Utils.getProperty("h2.sortUuidUnsigned", PREVIEW);

    System 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.
/**
     * System property <code>h2.sortNullsHigh</code> (default: false).<br />
     * 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.
     */
    public static final boolean SORT_NULLS_HIGH =
            Utils.getProperty("h2.sortNullsHigh", false);

    System property h2.splitFileSizeShift (default: 30).

The maximum file size of a split file is 1L << x.
/**
     * System property <code>h2.splitFileSizeShift</code> (default: 30).<br />
     * The maximum file size of a split file is 1L &lt;&lt; x.
     */
    public static final long SPLIT_FILE_SIZE_SHIFT =
            Utils.getProperty("h2.splitFileSizeShift", 30);

    System 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).
/**
     * System property <code>h2.syncMethod</code> (default: sync).<br />
     * 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).
     */
    public static final String SYNC_METHOD =
            Utils.getProperty("h2.syncMethod", "sync");

    System property h2.traceIO (default: false).

Trace all I/O operations.
/**
     * System property <code>h2.traceIO</code> (default: false).<br />
     * Trace all I/O operations.
     */
    public static final boolean TRACE_IO =
            Utils.getProperty("h2.traceIO", false);

    System property h2.threadDeadlockDetector
(default: false).

Detect thread deadlocks in a background thread.
/**
     * System property <code>h2.threadDeadlockDetector</code>
     * (default: false).<br />
     * Detect thread deadlocks in a background thread.
     */
    public static final boolean THREAD_DEADLOCK_DETECTOR =
            Utils.getProperty("h2.threadDeadlockDetector", false);

    System property h2.implicitRelativePath
(default: false).

If disabled, relative paths in database URLs need to be written as
jdbc:h2:./test instead of jdbc:h2:test.
/**
     * System property <code>h2.implicitRelativePath</code>
     * (default: false).<br />
     * If disabled, relative paths in database URLs need to be written as
     * jdbc:h2:./test instead of jdbc:h2:test.
     */
    public static final boolean IMPLICIT_RELATIVE_PATH =
            Utils.getProperty("h2.implicitRelativePath", false);

    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.
/**
     * System property <code>h2.urlMap</code> (default: null).<br />
     * 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.
     */
    public static final String URL_MAP =
            Utils.getProperty("h2.urlMap", null);

    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.
/**
     * System property <code>h2.useThreadContextClassLoader</code>
     * (default: false).<br />
     * Instead of using the default class loader when deserializing objects, the
     * current thread-context class loader will be used.
     */
    public static final boolean USE_THREAD_CONTEXT_CLASS_LOADER =
        Utils.getProperty("h2.useThreadContextClassLoader", false);

    System 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.
/**
     * System property <code>h2.serializeJavaObject</code>
     * (default: true).<br />
     * <b>If true</b>, 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).
     * <br />
     * <b>If false</b>, 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).
     * <br />
     * 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.
     * <br />
     * The string representation of the values use the toString method of
     * object.
     * <br />
     * 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.
     * <br />
     * 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.
     */
    public static boolean serializeJavaObject =
            Utils.getProperty("h2.serializeJavaObject", true);

    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.
/**
     * System property <code>h2.javaObjectSerializer</code>
     * (default: null).<br />
     * 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.
     */
    public static final String JAVA_OBJECT_SERIALIZER =
            Utils.getProperty("h2.javaObjectSerializer", null);

    System property h2.customDataTypesHandler
(default: null).

The CustomDataTypesHandler class name that is used
to provide support for user defined custom data types.
It must be the same on client and server to work correctly.
/**
     * System property <code>h2.customDataTypesHandler</code>
     * (default: null).<br />
     * The CustomDataTypesHandler class name that is used
     * to provide support for user defined custom data types.
     * It must be the same on client and server to work correctly.
     */
    public static final String CUSTOM_DATA_TYPES_HANDLER =
            Utils.getProperty("h2.customDataTypesHandler", null);

    System property h2.authConfigFile
(default: null).
 authConfigFile define the URL of configuration file of DefaultAuthenticator /**
     * System property <code>h2.authConfigFile</code>
     * (default: null).<br />
     * authConfigFile define the URL of configuration file
     * of {@link org.h2.security.auth.DefaultAuthenticator}
     *
     */
    public static final String AUTH_CONFIG_FILE =
            Utils.getProperty("h2.authConfigFile", null);

    private static final String H2_BASE_DIR = "h2.baseDir";

    private SysProperties() {
        // utility class
    }

    INTERNAL
/**
     * INTERNAL
     */
    public static void setBaseDir(String dir) {
        if (!dir.endsWith("/")) {
            dir += "/";
        }
        System.setProperty(H2_BASE_DIR, dir);
    }

    INTERNAL
/**
     * INTERNAL
     */
    public static String getBaseDir() {
        return Utils.getProperty(H2_BASE_DIR, null);
    }

    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/**
     * System property <code>h2.scriptDirectory</code> (default: empty
     * string).<br />
     * Relative or absolute directory where the script files are stored to or
     * read from.
     *
     * @return the current value
     */
    public static String getScriptDirectory() {
        return Utils.getProperty(H2_SCRIPT_DIRECTORY, "");
    }

    This method attempts to auto-scale some of our properties to take
advantage of more powerful machines out of the box. We assume that our
default properties are set correctly for approx. 1G of memory, and scale
them up if we have more.
/**
     * This method attempts to auto-scale some of our properties to take
     * advantage of more powerful machines out of the box. We assume that our
     * default properties are set correctly for approx. 1G of memory, and scale
     * them up if we have more.
     */
    private static int getAutoScaledForMemoryProperty(String key, int defaultValue) {
        String s = Utils.getProperty(key, null);
        if (s != null) {
            try {
                return Integer.decode(s);
            } catch (NumberFormatException e) {
                // ignore
            }
        }
        return Utils.scaleForAvailableMemory(defaultValue);
    }

}
/

com.h2database/ h2/ 1.4.199/ org/h2/engine/SysProperties.java
