org.h2.engine
Class Constants

java.lang.Object
  org.h2.engine.Constants

public class Constants
extends java.lang.Object

Constants are fixed values that are used in the whole database code.

Field Summary

static int	ALLOW_LITERALS_ALL Constant meaning both numbers and text is allowed in SQL statements.
static int	ALLOW_LITERALS_NONE Constant meaning no literals are allowed in SQL statements.
static int	ALLOW_LITERALS_NUMBERS Constant meaning only numbers are allowed in SQL statements (but no texts).
static boolean	BLOB_SEARCH Whether searching in Blob values should be supported.
static java.lang.String	BUILD_DATE The build date is updated for each public release.
static java.lang.String	BUILD_DATE_STABLE The build date is updated for each public release.
static int	BUILD_ID The build id is incremented for each public release.
static int	BUILD_ID_STABLE The build id of the last stable release.
static java.lang.String	BUILD_VENDOR_AND_VERSION If H2 is compiled to be included in a product, this should be set to a unique vendor id (to distinguish from official releases).
static int	CACHE_MIN_RECORDS The minimum number of entries to keep in the cache.
static int	CACHE_SIZE_DEFAULT The default cache size in KB.
static java.lang.String	CACHE_TYPE_DEFAULT The default cache type.
static java.lang.String	CLUSTERING_DISABLED The value of the cluster setting if clustering is disabled.
static java.lang.String	CLUSTERING_ENABLED The value of the cluster setting if clustering is enabled (the actual value is checked later).
static java.lang.String	CONN_URL_COLUMNLIST The database URL used when calling a function if only the column list should be returned.
static java.lang.String	CONN_URL_INTERNAL The database URL used when calling a function if the data should be returned.
static int	COST_ROW_OFFSET The cost is calculated on rowcount + this offset, to avoid using the wrong or no index if the table contains no rows _currently_ (when preparing the statement)
static int	DEADLOCK_CHECK The number of milliseconds after which to check for a deadlock if locking is not successful.
static int	DEFAULT_HTTP_PORT The default port number of the HTTP server (for the H2 Console).
static int	DEFAULT_LOCK_MODE The default value for the LOCK_MODE setting.
static int	DEFAULT_MAX_LENGTH_INPLACE_LOB The default maximum length of an LOB that is stored in the database file.
static int	DEFAULT_MAX_LENGTH_INPLACE_LOB2 The default maximum length of an LOB that is stored with the record itself.
static long	DEFAULT_MAX_LOG_SIZE The default value for the maximum transaction log size.
static int	DEFAULT_MAX_MEMORY_ROWS The default maximum number of rows to be kept in memory in a result set.
static int	DEFAULT_MAX_MEMORY_UNDO The default value for the MAX_MEMORY_UNDO setting.
static int	DEFAULT_MAX_OPERATION_MEMORY The default for the setting MAX_OPERATION_MEMORY.
static int	DEFAULT_PAGE_SIZE The default page size to use for new databases.
static int	DEFAULT_RESULT_SET_CONCURRENCY The default result set concurrency for statements created with Connection.createStatement() or prepareStatement(String sql).
static int	DEFAULT_TCP_PORT The default port of the TCP server.
static int	DEFAULT_WRITE_DELAY The default delay in milliseconds before the transaction log is written.
static int	ENCRYPTION_KEY_HASH_ITERATIONS The password is hashed this many times to slow down dictionary attacks.
static int	FILE_BLOCK_SIZE The block of a file.
static int	INITIAL_LOCK_TIMEOUT For testing, the lock timeout is smaller than for interactive use cases.
static int	IO_BUFFER_SIZE The block size for I/O operations.
static int	IO_BUFFER_SIZE_COMPRESS The block size used to compress data in the LZFOutputStream.
static int	LOCK_MODE_OFF The lock mode that means no locking is used at all.
static int	LOCK_MODE_READ_COMMITTED The lock mode that means read locks are acquired, but they are released immediately after the statement is executed.
static int	LOCK_MODE_TABLE The lock mode that means table level locking is used for reads and writes.
static int	LOCK_MODE_TABLE_GC The lock mode that means table level locking is used for reads and writes.
static int	LOCK_SLEEP The number of milliseconds to wait between checking the .lock.db file still exists once a database is locked.
static int	MAX_PARAMETER_INDEX The highest possible parameter index.
static int	MEMORY_DATA The memory needed by a object of class Data
static int	MEMORY_FACTOR This value is used to calculate the average memory usage.
static int	MEMORY_OBJECT The memory needed by a regular object with at least one field.
static int	MEMORY_PAGE_BTREE The memory needed by an object of class PageBtree.
static int	MEMORY_PAGE_DATA The memory needed by an object of class PageData.
static int	MEMORY_PAGE_DATA_OVERFLOW The memory needed by an object of class PageDataOverflow.
static int	MEMORY_POINTER The memory needed by a pointer.
static int	MEMORY_ROW The memory needed by a Row.
static int	MIN_WRITE_DELAY The minimum write delay that causes commits to be delayed.
static java.lang.String	PREFIX_INDEX The name prefix used for indexes that are not explicitly named.
static java.lang.String	PREFIX_JOIN The name prefix used for synthetic nested join tables.
static java.lang.String	PREFIX_PRIMARY_KEY The name prefix used for primary key constraints that are not explicitly named.
static java.lang.String	PUBLIC_ROLE_NAME Every user belongs to this role.
static int	SALT_LEN The number of bytes in random salt that is used to hash passwords.
static java.lang.String	SCHEMA_MAIN The name of the default schema.
static int	SELECTIVITY_DEFAULT The default selectivity (used if the selectivity is not calculated).
static int	SELECTIVITY_DISTINCT_COUNT The number of distinct values to keep in memory when running ANALYZE.
static java.lang.String	SERVER_PROPERTIES_DIR The default directory name of the server properties file for the H2 Console.
static java.lang.String	SERVER_PROPERTIES_NAME The name of the server properties file for the H2 Console.
static long	SLOW_QUERY_LIMIT_MS Queries that take longer than this number of milliseconds are written to the trace file with the level info.
static java.lang.String	START_URL The database URL prefix of this database.
static java.lang.String	SUFFIX_DB_FILE The file name suffix of all database files.
static java.lang.String	SUFFIX_LOB_FILE The file name suffix of large object files.
static java.lang.String	SUFFIX_LOBS_DIRECTORY The suffix of the directory name used if LOB objects are stored in a directory.
static java.lang.String	SUFFIX_LOCK_FILE The file name suffix of file lock files that are used to make sure a database is open by only one process at any time.
static java.lang.String	SUFFIX_PAGE_FILE The file name suffix of page files.
static java.lang.String	SUFFIX_TEMP_FILE The file name suffix of temporary files.
static java.lang.String	SUFFIX_TRACE_FILE The file name suffix of trace files.
static int	TCP_PROTOCOL_VERSION_6 The TCP protocol version number 6.
static int	TCP_PROTOCOL_VERSION_7 The TCP protocol version number 7.
static int	TCP_PROTOCOL_VERSION_8 The TCP protocol version number 8.
static int	THROTTLE_DELAY The delay that is to be used if throttle has been enabled.
static int	UNDO_BLOCK_SIZE The maximum size of an undo log block.
static java.lang.String	URL_FORMAT The database URL format in simplified Backus-Naur form.
static java.lang.String	USER_PACKAGE The package name of user defined classes.
static java.lang.String	UTF8 Name of the character encoding format.
static int	VERSION_MAJOR The major version of this database.
static int	VERSION_MINOR The minor version of this database.
static int	VIEW_COST_CACHE_MAX_AGE The maximum time in milliseconds to keep the cost of a view. 10000 means 10 seconds.
static int	VIEW_INDEX_CACHE_SIZE The name of the index cache that is used for temporary view (subqueries used as tables).

Method Summary

static java.lang.String	getFullVersion() Get the complete version number of this database, consisting of the major version, the minor version, the build id, and the build date.
static java.lang.String	getVersion() Get the version of this product, consisting of major version, minor version, and build id.
static java.lang.Object	getVersionStable() Get the last stable version name.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BUILD_DATE

public static final java.lang.String BUILD_DATE

The build date is updated for each public release.

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BUILD_DATE_STABLE

public static final java.lang.String BUILD_DATE_STABLE

The build date is updated for each public release.

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BUILD_ID

public static final int BUILD_ID

The build id is incremented for each public release.

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BUILD_ID_STABLE

public static final int BUILD_ID_STABLE

The build id of the last stable release.

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BUILD_VENDOR_AND_VERSION

public static final java.lang.String BUILD_VENDOR_AND_VERSION

If H2 is compiled to be included in a product, this should be set to a unique vendor id (to distinguish from official releases). Additionally, a version number should be set to distinguish releases. Example: ACME_SVN1651_BUILD3

TCP_PROTOCOL_VERSION_6

public static final int TCP_PROTOCOL_VERSION_6

The TCP protocol version number 6.

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TCP_PROTOCOL_VERSION_7

public static final int TCP_PROTOCOL_VERSION_7

The TCP protocol version number 7.

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TCP_PROTOCOL_VERSION_8

public static final int TCP_PROTOCOL_VERSION_8

The TCP protocol version number 8.

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VERSION_MAJOR

public static final int VERSION_MAJOR

The major version of this database.

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VERSION_MINOR

public static final int VERSION_MINOR

The minor version of this database.

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LOCK_MODE_OFF

public static final int LOCK_MODE_OFF

The lock mode that means no locking is used at all.

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LOCK_MODE_READ_COMMITTED

public static final int LOCK_MODE_READ_COMMITTED

The lock mode that means read locks are acquired, but they are released immediately after the statement is executed.

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LOCK_MODE_TABLE

public static final int LOCK_MODE_TABLE

The lock mode that means table level locking is used for reads and writes.

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LOCK_MODE_TABLE_GC

public static final int LOCK_MODE_TABLE_GC

The lock mode that means table level locking is used for reads and writes. If a table is locked, System.gc is called to close forgotten connections.

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ALLOW_LITERALS_ALL

public static final int ALLOW_LITERALS_ALL

Constant meaning both numbers and text is allowed in SQL statements.

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ALLOW_LITERALS_NONE

public static final int ALLOW_LITERALS_NONE

Constant meaning no literals are allowed in SQL statements.

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ALLOW_LITERALS_NUMBERS

public static final int ALLOW_LITERALS_NUMBERS

Constant meaning only numbers are allowed in SQL statements (but no texts).

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BLOB_SEARCH

public static final boolean BLOB_SEARCH

Whether searching in Blob values should be supported.

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CACHE_MIN_RECORDS

public static final int CACHE_MIN_RECORDS

The minimum number of entries to keep in the cache.

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CACHE_SIZE_DEFAULT

public static final int CACHE_SIZE_DEFAULT

The default cache size in KB.

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CACHE_TYPE_DEFAULT

public static final java.lang.String CACHE_TYPE_DEFAULT

The default cache type.

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CLUSTERING_DISABLED

public static final java.lang.String CLUSTERING_DISABLED

The value of the cluster setting if clustering is disabled.

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CLUSTERING_ENABLED

public static final java.lang.String CLUSTERING_ENABLED

The value of the cluster setting if clustering is enabled (the actual value is checked later).

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CONN_URL_COLUMNLIST

public static final java.lang.String CONN_URL_COLUMNLIST

The database URL used when calling a function if only the column list should be returned.

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CONN_URL_INTERNAL

public static final java.lang.String CONN_URL_INTERNAL

The database URL used when calling a function if the data should be returned.

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COST_ROW_OFFSET

public static final int COST_ROW_OFFSET

The cost is calculated on rowcount + this offset, to avoid using the wrong or no index if the table contains no rows _currently_ (when preparing the statement)

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DEADLOCK_CHECK

public static final int DEADLOCK_CHECK

The number of milliseconds after which to check for a deadlock if locking is not successful.

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DEFAULT_HTTP_PORT

public static final int DEFAULT_HTTP_PORT

The default port number of the HTTP server (for the H2 Console). This value is also in the documentation and in the Server javadoc.

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DEFAULT_LOCK_MODE

public static final int DEFAULT_LOCK_MODE

The default value for the LOCK_MODE setting.

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DEFAULT_MAX_LENGTH_INPLACE_LOB

public static final int DEFAULT_MAX_LENGTH_INPLACE_LOB

The default maximum length of an LOB that is stored in the database file.

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DEFAULT_MAX_LENGTH_INPLACE_LOB2

public static final int DEFAULT_MAX_LENGTH_INPLACE_LOB2

The default maximum length of an LOB that is stored with the record itself. Only used if h2.lobInDatabase is enabled.

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DEFAULT_MAX_LOG_SIZE

public static final long DEFAULT_MAX_LOG_SIZE

The default value for the maximum transaction log size.

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DEFAULT_MAX_MEMORY_ROWS

public static final int DEFAULT_MAX_MEMORY_ROWS

The default maximum number of rows to be kept in memory in a result set.

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DEFAULT_MAX_MEMORY_UNDO

public static final int DEFAULT_MAX_MEMORY_UNDO

The default value for the MAX_MEMORY_UNDO setting.

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DEFAULT_MAX_OPERATION_MEMORY

public static final int DEFAULT_MAX_OPERATION_MEMORY

The default for the setting MAX_OPERATION_MEMORY.

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DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

The default page size to use for new databases.

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DEFAULT_RESULT_SET_CONCURRENCY

public static final int DEFAULT_RESULT_SET_CONCURRENCY

The default result set concurrency for statements created with Connection.createStatement() or prepareStatement(String sql).

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DEFAULT_TCP_PORT

public static final int DEFAULT_TCP_PORT

The default port of the TCP server. This port is also used in the documentation and in the Server javadoc.

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DEFAULT_WRITE_DELAY

public static final int DEFAULT_WRITE_DELAY

The default delay in milliseconds before the transaction log is written.

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ENCRYPTION_KEY_HASH_ITERATIONS

public static final int ENCRYPTION_KEY_HASH_ITERATIONS

The password is hashed this many times to slow down dictionary attacks.

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FILE_BLOCK_SIZE

public static final int FILE_BLOCK_SIZE

The block of a file. It is also the encryption block size.

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INITIAL_LOCK_TIMEOUT

public static final int INITIAL_LOCK_TIMEOUT

For testing, the lock timeout is smaller than for interactive use cases. This value could be increased to about 5 or 10 seconds.

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IO_BUFFER_SIZE

public static final int IO_BUFFER_SIZE

The block size for I/O operations.

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IO_BUFFER_SIZE_COMPRESS

public static final int IO_BUFFER_SIZE_COMPRESS

The block size used to compress data in the LZFOutputStream.

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LOCK_SLEEP

public static final int LOCK_SLEEP

The number of milliseconds to wait between checking the .lock.db file still exists once a database is locked.

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MAX_PARAMETER_INDEX

public static final int MAX_PARAMETER_INDEX

The highest possible parameter index.

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MEMORY_DATA

public static final int MEMORY_DATA

The memory needed by a object of class Data

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MEMORY_FACTOR

public static final int MEMORY_FACTOR

This value is used to calculate the average memory usage.

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MEMORY_OBJECT

public static final int MEMORY_OBJECT

The memory needed by a regular object with at least one field.

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MEMORY_PAGE_BTREE

public static final int MEMORY_PAGE_BTREE

The memory needed by an object of class PageBtree.

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MEMORY_PAGE_DATA

public static final int MEMORY_PAGE_DATA

The memory needed by an object of class PageData.

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MEMORY_PAGE_DATA_OVERFLOW

public static final int MEMORY_PAGE_DATA_OVERFLOW

The memory needed by an object of class PageDataOverflow.

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MEMORY_POINTER

public static final int MEMORY_POINTER

The memory needed by a pointer.

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MEMORY_ROW

public static final int MEMORY_ROW

The memory needed by a Row.

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MIN_WRITE_DELAY

public static final int MIN_WRITE_DELAY

The minimum write delay that causes commits to be delayed.

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PREFIX_INDEX

public static final java.lang.String PREFIX_INDEX

The name prefix used for indexes that are not explicitly named.

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PREFIX_JOIN

public static final java.lang.String PREFIX_JOIN

The name prefix used for synthetic nested join tables.

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PREFIX_PRIMARY_KEY

public static final java.lang.String PREFIX_PRIMARY_KEY

The name prefix used for primary key constraints that are not explicitly named.

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PUBLIC_ROLE_NAME

public static final java.lang.String PUBLIC_ROLE_NAME

Every user belongs to this role.

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SALT_LEN

public static final int SALT_LEN

The number of bytes in random salt that is used to hash passwords.

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SCHEMA_MAIN

public static final java.lang.String SCHEMA_MAIN

The name of the default schema.

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SELECTIVITY_DEFAULT

public static final int SELECTIVITY_DEFAULT

The default selectivity (used if the selectivity is not calculated).

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SELECTIVITY_DISTINCT_COUNT

public static final int SELECTIVITY_DISTINCT_COUNT

The number of distinct values to keep in memory when running ANALYZE.

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SERVER_PROPERTIES_DIR

public static final java.lang.String SERVER_PROPERTIES_DIR

The default directory name of the server properties file for the H2 Console.

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SERVER_PROPERTIES_NAME

public static final java.lang.String SERVER_PROPERTIES_NAME

The name of the server properties file for the H2 Console.

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SLOW_QUERY_LIMIT_MS

public static final long SLOW_QUERY_LIMIT_MS

Queries that take longer than this number of milliseconds are written to the trace file with the level info.

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START_URL

public static final java.lang.String START_URL

The database URL prefix of this database.

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SUFFIX_DB_FILE

public static final java.lang.String SUFFIX_DB_FILE

The file name suffix of all database files.

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SUFFIX_LOB_FILE

public static final java.lang.String SUFFIX_LOB_FILE

The file name suffix of large object files.

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SUFFIX_LOBS_DIRECTORY

public static final java.lang.String SUFFIX_LOBS_DIRECTORY

The suffix of the directory name used if LOB objects are stored in a directory.

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SUFFIX_LOCK_FILE

public static final java.lang.String SUFFIX_LOCK_FILE

The file name suffix of file lock files that are used to make sure a database is open by only one process at any time.

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SUFFIX_PAGE_FILE

public static final java.lang.String SUFFIX_PAGE_FILE

The file name suffix of page files.

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SUFFIX_TEMP_FILE

public static final java.lang.String SUFFIX_TEMP_FILE

The file name suffix of temporary files.

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SUFFIX_TRACE_FILE

public static final java.lang.String SUFFIX_TRACE_FILE

The file name suffix of trace files.

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THROTTLE_DELAY

public static final int THROTTLE_DELAY

The delay that is to be used if throttle has been enabled.

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UNDO_BLOCK_SIZE

public static final int UNDO_BLOCK_SIZE

The maximum size of an undo log block.

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URL_FORMAT

public static final java.lang.String URL_FORMAT

The database URL format in simplified Backus-Naur form.

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USER_PACKAGE

public static final java.lang.String USER_PACKAGE

The package name of user defined classes.

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UTF8

public static final java.lang.String UTF8

Name of the character encoding format.

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VIEW_COST_CACHE_MAX_AGE

public static final int VIEW_COST_CACHE_MAX_AGE

The maximum time in milliseconds to keep the cost of a view. 10000 means 10 seconds.

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VIEW_INDEX_CACHE_SIZE

public static final int VIEW_INDEX_CACHE_SIZE

The name of the index cache that is used for temporary view (subqueries used as tables).

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Method Detail

getVersion

public static java.lang.String getVersion()

Get the version of this product, consisting of major version, minor version, and build id.

Returns:

the version number

getVersionStable

public static java.lang.Object getVersionStable()

Get the last stable version name.

Returns:

the version number

getFullVersion

public static java.lang.String getFullVersion()

Get the complete version number of this database, consisting of the major version, the minor version, the build id, and the build date.

Returns:

the complete version