com.sleepycat.db
Class Db

java.lang.Object
  |
  +--com.sleepycat.db.Db

public class Db

extends Object

The Db handle is the handle for a Berkeley DB database, which may or may not be part of a database environment.

The handle should not be closed while any other handle that refers to the database is in use; for example, database handles must not be closed while cursor handles into the database remain open, or transactions that include operations on the database have not yet been committed or aborted. Once the Db.close, Db.remove, or Db.rename methods are called, the handle may not be accessed again, regardless of the method's return.

Field Summary

static int	DB_AFTER A constant used to configure the system.
static int	DB_AGGRESSIVE A constant used to configure the system.
static int	DB_APPEND A constant used to configure the system.
static int	DB_ARCH_ABS A constant used to configure the system.
static int	DB_ARCH_DATA A constant used to configure the system.
static int	DB_ARCH_LOG A constant used to configure the system.
static int	DB_ARCH_REMOVE A constant used to configure the system.
static int	DB_AUTO_COMMIT A constant used to configure the system.
static int	DB_BEFORE A constant used to configure the system.
static int	DB_BTREE A constant used to configure the system.
static int	DB_CACHED_COUNTS
static int	DB_CDB_ALLDB A constant used to configure the system.
static int	DB_CHKSUM A constant used to configure the system.
static int	DB_CONSUME A constant used to configure the system.
static int	DB_CONSUME_WAIT A constant used to configure the system.
static int	DB_CREATE A constant used to configure the system.
static int	DB_CURRENT A constant used to configure the system.
static int	DB_CXX_NO_EXCEPTIONS
static int	DB_DBT_MALLOC A constant used to configure the system.
static int	DB_DBT_PARTIAL A constant used to configure the system.
static int	DB_DBT_REALLOC A constant used to configure the system.
static int	DB_DBT_USERMEM A constant used to configure the system.
static int	DB_DIRECT_DB A constant used to configure the system.
static int	DB_DIRECT_LOG A constant used to configure the system.
static int	DB_DIRTY_READ A constant used to configure the system.
static int	DB_DONOTINDEX A constant used to configure the system.
static int	DB_DUP A constant used to configure the system.
static int	DB_DUPSORT A constant used to configure the system.
static int	DB_EID_BROADCAST A constant used to configure the system.
static int	DB_EID_INVALID
static int	DB_ENCRYPT A constant used to configure the system.
static int	DB_ENCRYPT_AES A constant used to configure the system.
static int	DB_EXCL A constant used to configure the system.
static int	DB_FAST_STAT A constant used to configure the system.
static int	DB_FILEOPEN
static int	DB_FIRST A constant used to configure the system.
static int	DB_FLUSH A constant used to configure the system.
static int	DB_FORCE A constant used to configure the system.
static int	DB_GET_BOTH A constant used to configure the system.
static int	DB_GET_BOTH_RANGE A constant used to configure the system.
static int	DB_GET_RECNO A constant used to configure the system.
static int	DB_HASH A constant used to configure the system.
static int	DB_INIT_CDB A constant used to configure the system.
static int	DB_INIT_LOCK A constant used to configure the system.
static int	DB_INIT_LOG A constant used to configure the system.
static int	DB_INIT_MPOOL A constant used to configure the system.
static int	DB_INIT_REP A constant used to configure the system.
static int	DB_INIT_TXN A constant used to configure the system.
static int	DB_JOIN_ITEM A constant used to configure the system.
static int	DB_JOIN_NOSORT A constant used to configure the system.
static int	DB_JOINENV A constant used to configure the system.
static int	DB_KEYEMPTY A constant used to configure the system.
static int	DB_KEYEXIST A constant used to configure the system.
static int	DB_KEYFIRST A constant used to configure the system.
static int	DB_KEYLAST A constant used to configure the system.
static int	DB_LAST A constant used to configure the system.
static int	DB_LOCK_DEADLOCK
static int	DB_LOCK_DEFAULT A constant used to configure the system.
static int	DB_LOCK_EXPIRE A constant used to configure the system.
static int	DB_LOCK_GET A constant used to configure the system.
static int	DB_LOCK_GET_TIMEOUT A constant used to configure the system.
static int	DB_LOCK_IREAD A constant used to configure the system.
static int	DB_LOCK_IWR A constant used to configure the system.
static int	DB_LOCK_IWRITE A constant used to configure the system.
static int	DB_LOCK_MAXLOCKS A constant used to configure the system.
static int	DB_LOCK_MINLOCKS A constant used to configure the system.
static int	DB_LOCK_MINWRITE A constant used to configure the system.
static int	DB_LOCK_NOTGRANTED
static int	DB_LOCK_NOWAIT A constant used to configure the system.
static int	DB_LOCK_OLDEST A constant used to configure the system.
static int	DB_LOCK_PUT A constant used to configure the system.
static int	DB_LOCK_PUT_ALL A constant used to configure the system.
static int	DB_LOCK_PUT_OBJ A constant used to configure the system.
static int	DB_LOCK_RANDOM A constant used to configure the system.
static int	DB_LOCK_READ A constant used to configure the system.
static int	DB_LOCK_TIMEOUT A constant used to configure the system.
static int	DB_LOCK_WRITE A constant used to configure the system.
static int	DB_LOCK_YOUNGEST A constant used to configure the system.
static int	DB_LOCKDOWN A constant used to configure the system.
static int	DB_LOG_AUTOREMOVE A constant used to configure the system.
static int	DB_MPOOL_NOFILE A constant used to configure the system.
static int	DB_MULTIPLE A constant used to configure the system.
static int	DB_MULTIPLE_KEY A constant used to configure the system.
static int	DB_NEXT A constant used to configure the system.
static int	DB_NEXT_DUP A constant used to configure the system.
static int	DB_NEXT_NODUP A constant used to configure the system.
static int	DB_NODUPDATA A constant used to configure the system.
static int	DB_NOLOCKING A constant used to configure the system.
static int	DB_NOMMAP A constant used to configure the system.
static int	DB_NOORDERCHK A constant used to configure the system.
static int	DB_NOOVERWRITE A constant used to configure the system.
static int	DB_NOPANIC A constant used to configure the system.
static int	DB_NOSERVER
static int	DB_NOSERVER_HOME A constant used to configure the system.
static int	DB_NOSERVER_ID A constant used to configure the system.
static int	DB_NOSYNC A constant used to configure the system.
static int	DB_NOTFOUND A constant used to configure the system.
static int	DB_OLD_VERSION A constant used to configure the system.
static int	DB_ORDERCHKONLY A constant used to configure the system.
static int	DB_OVERWRITE A constant used to configure the system.
static int	DB_PAGE_NOTFOUND
static int	DB_PANIC_ENVIRONMENT A constant used to configure the system.
static int	DB_POSITION A constant used to configure the system.
static int	DB_PREV A constant used to configure the system.
static int	DB_PREV_NODUP A constant used to configure the system.
static int	DB_PRINTABLE A constant used to configure the system.
static int	DB_PRIORITY_DEFAULT A constant used to configure the system.
static int	DB_PRIORITY_HIGH A constant used to configure the system.
static int	DB_PRIORITY_LOW A constant used to configure the system.
static int	DB_PRIORITY_VERY_HIGH A constant used to configure the system.
static int	DB_PRIORITY_VERY_LOW A constant used to configure the system.
static int	DB_PRIVATE A constant used to configure the system.
static int	DB_QUEUE A constant used to configure the system.
static int	DB_RDONLY A constant used to configure the system.
static int	DB_RECNO A constant used to configure the system.
static int	DB_RECNUM A constant used to configure the system.
static int	DB_RECORDCOUNT
static int	DB_RECOVER A constant used to configure the system.
static int	DB_RECOVER_FATAL A constant used to configure the system.
static int	DB_REGION_INIT A constant used to configure the system.
static int	DB_RENUMBER A constant used to configure the system.
static int	DB_REP_CLIENT A constant used to configure the system.
static int	DB_REP_DUPMASTER A constant used to configure the system.
static int	DB_REP_HANDLE_DEAD A constant used to configure the system.
static int	DB_REP_HOLDELECTION A constant used to configure the system.
static int	DB_REP_ISPERM A constant used to configure the system.
static int	DB_REP_LOGSONLY A constant used to configure the system.
static int	DB_REP_MASTER A constant used to configure the system.
static int	DB_REP_NEWMASTER A constant used to configure the system.
static int	DB_REP_NEWSITE A constant used to configure the system.
static int	DB_REP_NOBUFFER A constant used to configure the system.
static int	DB_REP_NOTPERM A constant used to configure the system.
static int	DB_REP_OUTDATED A constant used to configure the system.
static int	DB_REP_PERMANENT A constant used to configure the system.
static int	DB_REP_UNAVAIL A constant used to configure the system.
static int	DB_REVSPLITOFF A constant used to configure the system.
static int	DB_RMW A constant used to configure the system.
static int	DB_RPCCLIENT A constant used to configure the system.
static int	DB_RUNRECOVERY
static int	DB_SALVAGE A constant used to configure the system.
static int	DB_SECONDARY_BAD A constant used to configure the system.
static int	DB_SET A constant used to configure the system.
static int	DB_SET_LOCK_TIMEOUT A constant used to configure the system.
static int	DB_SET_RANGE A constant used to configure the system.
static int	DB_SET_RECNO A constant used to configure the system.
static int	DB_SET_TXN_TIMEOUT A constant used to configure the system.
static int	DB_SNAPSHOT A constant used to configure the system.
static int	DB_STAT_CLEAR A constant used to configure the system.
static int	DB_SYSTEM_MEM A constant used to configure the system.
static int	DB_THREAD A constant used to configure the system.
static int	DB_TIME_NOTGRANTED A constant used to configure the system.
static int	DB_TRUNCATE A constant used to configure the system.
static int	DB_TXN_ABORT A constant used to configure the system.
static int	DB_TXN_APPLY A constant used to configure the system.
static int	DB_TXN_BACKWARD_ROLL A constant used to configure the system.
static int	DB_TXN_FORWARD_ROLL A constant used to configure the system.
static int	DB_TXN_NOSYNC A constant used to configure the system.
static int	DB_TXN_NOT_DURABLE A constant used to configure the system.
static int	DB_TXN_NOWAIT A constant used to configure the system.
static int	DB_TXN_PRINT A constant used to configure the system.
static int	DB_TXN_SYNC A constant used to configure the system.
static int	DB_TXN_WRITE_NOSYNC A constant used to configure the system.
static int	DB_UNKNOWN A constant used to configure the system.
static int	DB_UPGRADE A constant used to configure the system.
static int	DB_USE_ENVIRON A constant used to configure the system.
static int	DB_USE_ENVIRON_ROOT A constant used to configure the system.
static int	DB_VERB_CHKPOINT A constant used to configure the system.
static int	DB_VERB_DEADLOCK A constant used to configure the system.
static int	DB_VERB_RECOVERY A constant used to configure the system.
static int	DB_VERB_REPLICATION A constant used to configure the system.
static int	DB_VERB_WAITSFOR A constant used to configure the system.
static int	DB_VERIFY A constant used to configure the system.
static int	DB_VERIFY_BAD A constant used to configure the system.
static int	DB_VERSION_MAJOR
static int	DB_VERSION_MINOR
static int	DB_VERSION_PATCH
static int	DB_WRITECURSOR A constant used to configure the system.
static int	DB_XA_CREATE A constant used to configure the system.
static int	DB_XIDDATASIZE A constant used to configure the system.
static int	DB_YIELDCPU A constant used to configure the system.

Constructor Summary

Db(DbEnv dbenv, int flags)
The constructor creates a Db object that is the handle for a Berkeley DB database.

Method Summary

void	associate(DbTxn txnid, Db secondary, DbSecondaryKeyCreate callback, int flags)
void	close(int flags) The Db.close method flushes any cached database information to disk, closes any open cursors, frees any allocated resources, and closes any underlying files.
Dbc	cursor(DbTxn txnid, int flags) The Db.cursor method returns a created database cursor.
int	del(DbTxn txnid, Dbt key, int flags) Deprecated. As of Berkeley DB 4.2, replaced by delete(DbTxn,Dbt,int)
int	delete(DbTxn txnid, Dbt key, int flags) The Db.delete method removes key/data pairs from the database.
void	err(int error, String message) The DbEnv.err, DbEnv.errx, Db.err and Db.errx methods provide error-messaging functionality for applications written using the Berkeley DB library.
void	errx(String message) The DbEnv.errx and Db.errx methods perform identically to the DbEnv.err and Db.err methods, except that they do not append the final separator characters and standard error string to the error message.
int	get_bt_minkey() Deprecated. As of Berkeley DB 4.2, replaced by getBtreeMinKey()
boolean	get_byteswapped() Deprecated. As of Berkeley DB 4.2, replaced by isByteSwapped()
int	get_cachesize_ncache() Deprecated. As of Berkeley DB 4.2, replaced by getCacheSizeNcache()
long	get_cachesize() Deprecated. As of Berkeley DB 4.2, replaced by getCacheSize()
String	get_dbname() Deprecated. As of Berkeley DB 4.2, replaced by getDatabaseName()
int	get_encrypt_flags() Deprecated. As of Berkeley DB 4.2, replaced by getEncryptFlags()
DbEnv	get_env() Deprecated. As of Berkeley DB 4.2, replaced by getDbEnv()
String	get_errpfx() Deprecated. As of Berkeley DB 4.2, replaced by getErrorPrefix()
String	get_filename() Deprecated. As of Berkeley DB 4.2, replaced by getFileName()
int	get_flags_raw()
int	get_flags() Deprecated. As of Berkeley DB 4.2, replaced by getFlags()
int	get_h_ffactor() Deprecated. As of Berkeley DB 4.2, replaced by getHashFillFactor()
int	get_h_nelem() Deprecated. As of Berkeley DB 4.2, replaced by getHashNumElements()
int	get_lorder() Deprecated. As of Berkeley DB 4.2, replaced by getByteOrder()
DbMpoolFile	get_mpf() The Db.get_mpf method returns the handle for the cache file underlying the database.
int	get_open_flags() Deprecated. As of Berkeley DB 4.2, replaced by getOpenFlags()
int	get_pagesize() Deprecated. As of Berkeley DB 4.2, replaced by getPageSize()
int	get_q_extentsize() Deprecated. As of Berkeley DB 4.2, replaced by getQueueExtentSize()
int	get_re_delim() Deprecated. As of Berkeley DB 4.2, replaced by getRecordDelimiter()
int	get_re_len() Deprecated. As of Berkeley DB 4.2, replaced by getRecordLength()
int	get_re_pad() Deprecated. As of Berkeley DB 4.2, replaced by getRecordPad()
String	get_re_source() Deprecated. As of Berkeley DB 4.2, replaced by getRecordSource()
boolean	get_transactional() Deprecated. As of Berkeley DB 4.2, replaced by isTransactional()
int	get_type() Deprecated. As of Berkeley DB 4.2, replaced by getDbType()
int	get(DbTxn txnid, Dbt key, Dbt pkey, Dbt data, int flags) The Db.get method retrieves key/data pairs from the database.
int	get(DbTxn txnid, Dbt key, Dbt data, int flags) The Db.get method retrieves key/data pairs from the database.
int	getBtreeMinKey() The Db.getBtreeMinKey method returns the minimum number of key/data pairs intended to be stored on any single Btree leaf page.
int	getByteOrder() The Db.getByteOrder method returns the database byte order; a byte order of 4,321 indicates a big endian order, and a byte order of 1,234 indicates a little endian order.
long	getCacheSize() The Db.getCacheSize method returns the size of the cache.
int	getCacheSizeNcache() The DbEnv.getCacheSizeNcache method returns the number of caches.
String	getDatabaseName() The Db.getDatabaseName method returns the current database name.
DbEnv	getDbEnv() The Db.getDbEnv method returns the handle for the database environment underlying the database.
int	getDbType() The Db.getDbType method returns the type of the underlying access method (and file format).
int	getEncryptFlags() The Db.getEncryptFlags method returns the encryption flags.
String	getErrorPrefix() The Db.getErrorPrefix method returns the error prefix.
String	getFileName() The Db.getFileName method returns the current filename.
int	getFlags() The Db.getFlags method returns the current flags.
int	getHashFillFactor() The Db.getHashFillFactor method returns the hash table density.
int	getHashNumElements() The Db.getHashNumElements method returns the estimate of the final size of the hash table.
int	getOpenFlags() The Db.getOpenFlags method returns the current open method flags.
int	getPageSize() The Db.getPageSize method returns the page size.
int	getQueueExtentSize() The Db.getQueueExtentSize method returns the number of pages in an extent.
int	getRecordDelimiter() The Db.getRecordDelimiter method returns the delimiting byte.
int	getRecordLength() The Db.getRecordLength method returns the record length.
int	getRecordPad() The Db.getRecordPad method returns the pad character.
String	getRecordSource() The Db.getRecordSource method returns the source file.
boolean	isByteSwapped() The Db.isByteSwapped method returns false if the underlying database files were created on an architecture of the same byte order as the current one, and true if they were not (that is, big-endian on a little-endian machine, or vice versa).
boolean	isEncrypted() The Db.isEncrypted method returns false if the underlying database files are encrypted and true if they are not.
boolean	isTransactional() The Db.isTransactional method returns true if the Db handle has been opened in a transactional mode.
Dbc	join(Dbc[] curslist, int flags) The Db.join method creates a specialized join cursor for use in performing equality or natural joins on secondary indices.
void	key_range(DbTxn txnid, Dbt key, DbKeyRange key_range, int flags) Deprecated. As of Berkeley DB 4.2, replaced by keyRange(DbTxn,Dbt,DbKeyRange,int)
void	keyRange(DbTxn txnid, Dbt key, DbKeyRange key_range, int flags) The Db.keyRange method returns an estimate of the proportion of keys that are less than, equal to, and greater than the specified key.
void	open(DbTxn txnid, String file, String database, int type, int flags, int mode) The Db.open method opens the database represented by the file and database parameters for both reading and writing.
int	pget(DbTxn txnid, Dbt key, Dbt pkey, Dbt data, int flags) Deprecated. Replaced in Berkeley DB 4.2 by get(DbTxn,Dbt,Dbt,Dbt,int)
int	put(DbTxn txnid, Dbt key, Dbt data, int flags) The Db.put method stores key/data pairs in the database.
void	remove(String file, String database, int flags) The Db.remove method removes the database specified by the file and database parameters.
void	rename(String file, String database, String newname, int flags) The Db.rename method renames the database specified by the file and database parameters to newname.
void	set_append_recno(DbAppendRecno db_append_recno_fcn) Deprecated. As of Berkeley DB 4.2, replaced by setAppendRecno(DbAppendRecno)
void	set_bt_compare(DbBtreeCompare bt_compare_fcn) Deprecated. As of Berkeley DB 4.2, replaced by setBtreeCompare(DbBtreeCompare)
void	set_bt_maxkey(int maxkey)
void	set_bt_minkey(int bt_minkey) Deprecated. As of Berkeley DB 4.2, replaced by setBtreeMinKey(int)
void	set_bt_prefix(DbBtreePrefix bt_prefix_fcn) Deprecated. As of Berkeley DB 4.2, replaced by setBtreePrefix(DbBtreePrefix)
void	set_cachesize(int gbytes, int bytes, int ncache) Deprecated. Replaced in Berkeley DB 4.2 by setCacheSize(long,int)
void	set_cachesize(long bytes, int ncache) Deprecated. As of Berkeley DB 4.2, replaced by setCacheSize(long,int)
void	set_dup_compare(DbDupCompare dup_compare_fcn) Deprecated. As of Berkeley DB 4.2, replaced by setDuplicateCompare(DbDupCompare)
void	set_encrypt(String passwd, int flags) Deprecated. As of Berkeley DB 4.2, replaced by setEncrypted(String,int)
void	set_errcall(DbErrcall db_errcall_fcn) Deprecated. Replaced in Berkeley DB 4.2 by setErrorHandler(DbErrorHandler)
void	set_error_stream(OutputStream stream) Deprecated. As of Berkeley DB 4.2, replaced by setErrorStream(java.io.OutputStream)
void	set_errpfx(String errpfx) Deprecated. As of Berkeley DB 4.2, replaced by setErrorPrefix(String)
void	set_feedback(DbFeedback feedback) Deprecated. Replaced in Berkeley DB 4.2 by setFeedbackHandler(DbFeedbackHandler)
void	set_flags(int flags) Deprecated. As of Berkeley DB 4.2, replaced by setFlags(int)
void	set_h_ffactor(int h_ffactor) Deprecated. As of Berkeley DB 4.2, replaced by setHashFillFactor(int)
void	set_h_hash(DbHash h_hash_fcn) Deprecated. As of Berkeley DB 4.2, replaced by setHash(DbHash)
void	set_h_nelem(int h_nelem) Deprecated. As of Berkeley DB 4.2, replaced by setHashNumElements(int)
void	set_lorder(int lorder) Deprecated. As of Berkeley DB 4.2, replaced by setByteOrder(int)
void	set_pagesize(long pagesize) Deprecated. As of Berkeley DB 4.2, replaced by setPageSize(long)
void	set_q_extentsize(int extentsize) Deprecated. As of Berkeley DB 4.2, replaced by setQueueExtentSize(int)
void	set_re_delim(int re_delim) Deprecated. As of Berkeley DB 4.2, replaced by setRecordDelimiter(int)
void	set_re_len(int re_len) Deprecated. As of Berkeley DB 4.2, replaced by setRecordLength(int)
void	set_re_pad(int re_pad) Deprecated. As of Berkeley DB 4.2, replaced by setRecordPad(int)
void	set_re_source(String source) Deprecated. As of Berkeley DB 4.2, replaced by setRecordSource(String)
void	setAppendRecno(DbAppendRecno db_append_recno_fcn)
void	setBtreeCompare(DbBtreeCompare bt_compare_fcn)
void	setBtreeMinKey(int bt_minkey) Set the minimum number of key/data pairs intended to be stored on any single Btree leaf page.
void	setBtreePrefix(DbBtreePrefix bt_prefix_fcn)
void	setByteOrder(int lorder) Set the byte order for integers in the stored database metadata.
void	setCacheSize(long bytes, int ncache) Set the size of the shared memory buffer pool -- that is, the cache.
void	setDuplicateCompare(DbDupCompare dup_compare_fcn)
void	setEncrypted(String passwd, int flags) Set the password used by the Berkeley DB library to perform encryption and decryption.
void	setErrorHandler(DbErrorHandler db_errcall_fcn) When an error occurs in the Berkeley DB library, an exception is thrown.
void	setErrorPrefix(String errpfx) Set the prefix string that appears before error messages issued by Berkeley DB.
void	setErrorStream(OutputStream stream) When an error occurs in the Berkeley DB library, an exception is thrown.
void	setFeedbackHandler(DbFeedbackHandler db_feedback_fcn)
void	setFlags(int flags) Configure a database.
void	setHash(DbHash h_hash_fcn)
void	setHashFillFactor(int h_ffactor) Set the desired density within the hash table.
void	setHashNumElements(int h_nelem) Set an estimate of the final size of the hash table.
void	setPageSize(long pagesize) Set the size of the pages used to hold items in the database, in bytes.
void	setPanicHandler(DbPanicHandler db_panic_fcn) Errors can occur in the Berkeley DB library where the only solution is to shut down the application and run recovery (for example, if Berkeley DB is unable to allocate heap memory).
void	setQueueExtentSize(int extentsize) Set the size of the extents used to hold pages in a Queue database, specified as a number of pages.
void	setRecordDelimiter(int re_delim) Set the delimiting byte used to mark the end of a record in the backing source file for the Recno access method.
void	setRecordLength(int re_len) For the Queue access method, specify that the records are of length re_len.
void	setRecordPad(int re_pad) Set the padding character for short, fixed-length records for the Queue and Recno access methods.
void	setRecordSource(String source) Set the underlying source file for the Recno access method.
Object	stat(int flags) The Db.stat method creates a statistical structure and fills it with statistics for the database.
void	sync(int flags) The Db.sync method flushes any cached information to disk.
int	truncate(DbTxn txnid, int flags) The Db.truncate method empties the database, discarding all records it contains.
void	upgrade(String file, int flags) The Db.upgrade method upgrades all of the databases included in the file file, if necessary.
void	verify(String file, String database, OutputStream outfile, int flags) The Db.verify method verifies the integrity of all databases in the file specified by the file parameter, and optionally outputs the databases' key/data pairs to the file stream specified by the outfile parameter.

Methods inherited from class java.lang.Object

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

Field Detail

DB_BTREE

public static final int DB_BTREE

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_DONOTINDEX

public static final int DB_DONOTINDEX

A constant used to configure the system. It is used in the following locations:

• associate(DbTxn,Db,DbSecondaryKeyCreate,int)
• DbSecondaryKeyCreate.secondaryKeyCreate(Db,Dbt,Dbt,Dbt)

See Also:

Constant Field Values

DB_FILEOPEN

public static final int DB_FILEOPEN

See Also:

Constant Field Values

DB_HASH

public static final int DB_HASH

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_KEYEMPTY

public static final int DB_KEYEMPTY

A constant used to configure the system. It is used in the following locations:

• delete(DbTxn,Dbt,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• Dbc.delete(int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

See Also:

Constant Field Values

DB_KEYEXIST

public static final int DB_KEYEXIST

A constant used to configure the system. It is used in the following locations:

• put(DbTxn,Dbt,Dbt,int)
• put(DbTxn,Dbt,Dbt,int)

See Also:

Constant Field Values

DB_LOCK_DEADLOCK

public static final int DB_LOCK_DEADLOCK

See Also:

Constant Field Values

DB_LOCK_NOTGRANTED

public static final int DB_LOCK_NOTGRANTED

See Also:

Constant Field Values

DB_NOSERVER

public static final int DB_NOSERVER

See Also:

Constant Field Values

DB_NOSERVER_HOME

public static final int DB_NOSERVER_HOME

A constant used to configure the system. It is used in the following locations:

• DbEnv.setRpcServer(DbClient,String,long,long,int)

See Also:

Constant Field Values

DB_NOSERVER_ID

public static final int DB_NOSERVER_ID

A constant used to configure the system. It is used in the following locations:

• DbEnv.setRpcServer(DbClient,String,long,long,int)

See Also:

Constant Field Values

DB_NOTFOUND

public static final int DB_NOTFOUND

A constant used to configure the system. It is used in the following locations:

• delete(DbTxn,Dbt,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)

See Also:

Constant Field Values

DB_OLD_VERSION

public static final int DB_OLD_VERSION

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_PAGE_NOTFOUND

public static final int DB_PAGE_NOTFOUND

See Also:

Constant Field Values

DB_QUEUE

public static final int DB_QUEUE

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_RECNO

public static final int DB_RECNO

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_REP_DUPMASTER

public static final int DB_REP_DUPMASTER

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

See Also:

Constant Field Values

DB_REP_HANDLE_DEAD

public static final int DB_REP_HANDLE_DEAD

A constant used to configure the system. It is used in the following locations:

• associate(DbTxn,Db,DbSecondaryKeyCreate,int)
• cursor(DbTxn,int)
• delete(DbTxn,Dbt,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• join(Dbc[],int)
• keyRange(DbTxn,Dbt,DbKeyRange,int)
• open(DbTxn,String,String,int,int,int)
• put(DbTxn,Dbt,Dbt,int)
• stat(int)
• sync(int)
• Dbc.count(int)
• Dbc.delete(int)
• Dbc.dup(int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)

See Also:

Constant Field Values

DB_REP_HOLDELECTION

public static final int DB_REP_HOLDELECTION

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

See Also:

Constant Field Values

DB_REP_NEWMASTER

public static final int DB_REP_NEWMASTER

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

See Also:

Constant Field Values

DB_REP_NEWSITE

public static final int DB_REP_NEWSITE

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

See Also:

Constant Field Values

DB_REP_OUTDATED

public static final int DB_REP_OUTDATED

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

See Also:

Constant Field Values

DB_RUNRECOVERY

public static final int DB_RUNRECOVERY

See Also:

Constant Field Values

DB_SECONDARY_BAD

public static final int DB_SECONDARY_BAD

A constant used to configure the system. It is used in the following locations:

• delete(DbTxn,Dbt,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• join(Dbc[],int)
• Dbc.delete(int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

See Also:

Constant Field Values

DB_TXN_ABORT

public static final int DB_TXN_ABORT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setAppDispatch(DbAppDispatch)
• DbAppDispatch.appDispatch(DbEnv,Dbt,DbLsn,int)

See Also:

Constant Field Values

DB_TXN_APPLY

public static final int DB_TXN_APPLY

A constant used to configure the system. It is used in the following locations:

• DbEnv.setAppDispatch(DbAppDispatch)
• DbAppDispatch.appDispatch(DbEnv,Dbt,DbLsn,int)

See Also:

Constant Field Values

DB_TXN_BACKWARD_ROLL

public static final int DB_TXN_BACKWARD_ROLL

A constant used to configure the system. It is used in the following locations:

• DbEnv.setAppDispatch(DbAppDispatch)
• DbAppDispatch.appDispatch(DbEnv,Dbt,DbLsn,int)

See Also:

Constant Field Values

DB_TXN_FORWARD_ROLL

public static final int DB_TXN_FORWARD_ROLL

A constant used to configure the system. It is used in the following locations:

• DbEnv.setAppDispatch(DbAppDispatch)
• DbAppDispatch.appDispatch(DbEnv,Dbt,DbLsn,int)

See Also:

Constant Field Values

DB_TXN_PRINT

public static final int DB_TXN_PRINT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setAppDispatch(DbAppDispatch)
• DbAppDispatch.appDispatch(DbEnv,Dbt,DbLsn,int)

See Also:

Constant Field Values

DB_UNKNOWN

public static final int DB_UNKNOWN

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

See Also:

Constant Field Values

DB_VERIFY_BAD

public static final int DB_VERIFY_BAD

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

See Also:

Constant Field Values

DB_AFTER

public static final int DB_AFTER

A constant used to configure the system. It is used in the following locations:

• Dbc.put(Dbt,Dbt,int)

DB_AGGRESSIVE

public static final int DB_AGGRESSIVE

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

DB_APPEND

public static final int DB_APPEND

A constant used to configure the system. It is used in the following locations:

• put(DbTxn,Dbt,Dbt,int)

DB_ARCH_ABS

public static final int DB_ARCH_ABS

A constant used to configure the system. It is used in the following locations:

• DbEnv.logArchive(int)

DB_ARCH_DATA

public static final int DB_ARCH_DATA

A constant used to configure the system. It is used in the following locations:

• DbEnv.logArchive(int)

DB_ARCH_LOG

public static final int DB_ARCH_LOG

A constant used to configure the system. It is used in the following locations:

• DbEnv.logArchive(int)

DB_ARCH_REMOVE

public static final int DB_ARCH_REMOVE

A constant used to configure the system. It is used in the following locations:

• DbEnv.logArchive(int)

DB_AUTO_COMMIT

public static final int DB_AUTO_COMMIT

A constant used to configure the system. It is used in the following locations:

• associate(DbTxn,Db,DbSecondaryKeyCreate,int)
• delete(DbTxn,Dbt,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• open(DbTxn,String,String,int,int,int)
• put(DbTxn,Dbt,Dbt,int)
• truncate(DbTxn,int)
• DbEnv.dbRemove(DbTxn,String,String,int)
• DbEnv.dbRename(DbTxn,String,String,String,int)
• DbEnv.setFlags(int,boolean)

DB_BEFORE

public static final int DB_BEFORE

A constant used to configure the system. It is used in the following locations:

• Dbc.put(Dbt,Dbt,int)

DB_CACHED_COUNTS

public static final int DB_CACHED_COUNTS

DB_CDB_ALLDB

public static final int DB_CDB_ALLDB

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_CHKSUM

public static final int DB_CHKSUM

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_CONSUME

public static final int DB_CONSUME

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)

DB_CONSUME_WAIT

public static final int DB_CONSUME_WAIT

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)

DB_CREATE

public static final int DB_CREATE

A constant used to configure the system. It is used in the following locations:

• associate(DbTxn,Db,DbSecondaryKeyCreate,int)
• open(DbTxn,String,String,int,int,int)
• DbEnv.open(String,int,int)

DB_CURRENT

public static final int DB_CURRENT

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)

DB_CXX_NO_EXCEPTIONS

public static final int DB_CXX_NO_EXCEPTIONS

DB_DBT_MALLOC

public static final int DB_DBT_MALLOC

A constant used to configure the system. It is used in the following locations:

• Dbt.setFlags(int)

DB_DBT_PARTIAL

public static final int DB_DBT_PARTIAL

A constant used to configure the system. It is used in the following locations:

• Dbt.setFlags(int)

DB_DBT_REALLOC

public static final int DB_DBT_REALLOC

A constant used to configure the system. It is used in the following locations:

• Dbt.setFlags(int)

DB_DBT_USERMEM

public static final int DB_DBT_USERMEM

A constant used to configure the system. It is used in the following locations:

• Dbt.setFlags(int)

DB_DIRECT_DB

public static final int DB_DIRECT_DB

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_DIRECT_LOG

public static final int DB_DIRECT_LOG

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_DIRTY_READ

public static final int DB_DIRTY_READ

A constant used to configure the system. It is used in the following locations:

• cursor(DbTxn,int)
• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• join(Dbc[],int)
• open(DbTxn,String,String,int,int,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbEnv.txnBegin(DbTxn,int)

DB_DUP

public static final int DB_DUP

A constant used to configure the system. It is used in the following locations:

• setFlags(int)
• setFlags(int)

DB_DUPSORT

public static final int DB_DUPSORT

A constant used to configure the system. It is used in the following locations:

• setFlags(int)
• setFlags(int)
• upgrade(String,int)

DB_EID_BROADCAST

public static final int DB_EID_BROADCAST

A constant used to configure the system. It is used in the following locations:

• DbEnv.setReplicationTransport(int,DbRepTransport)
• DbRepTransport.send(DbEnv,Dbt,Dbt,DbLsn,int,int)

DB_EID_INVALID

public static final int DB_EID_INVALID

DB_ENCRYPT

public static final int DB_ENCRYPT

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_ENCRYPT_AES

public static final int DB_ENCRYPT_AES

A constant used to configure the system. It is used in the following locations:

• setEncrypted(String,int)
• DbEnv.setEncrypted(String,int)

DB_EXCL

public static final int DB_EXCL

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

DB_FAST_STAT

public static final int DB_FAST_STAT

A constant used to configure the system. It is used in the following locations:

• stat(int)

DB_FIRST

public static final int DB_FIRST

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)
• DbEnv.txnRecover(int,int)

DB_FLUSH

public static final int DB_FLUSH

A constant used to configure the system. It is used in the following locations:

• DbEnv.logPut(DbLsn,Dbt,int)

DB_FORCE

public static final int DB_FORCE

A constant used to configure the system. It is used in the following locations:

• DbEnv.remove(String,int)
• DbEnv.txnCheckpoint(int,int,int)

DB_GET_BOTH

public static final int DB_GET_BOTH

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_GET_BOTH_RANGE

public static final int DB_GET_BOTH_RANGE

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_GET_RECNO

public static final int DB_GET_RECNO

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_INIT_CDB

public static final int DB_INIT_CDB

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_INIT_LOCK

public static final int DB_INIT_LOCK

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_INIT_LOG

public static final int DB_INIT_LOG

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_INIT_MPOOL

public static final int DB_INIT_MPOOL

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_INIT_REP

public static final int DB_INIT_REP

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_INIT_TXN

public static final int DB_INIT_TXN

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_JOINENV

public static final int DB_JOINENV

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_JOIN_ITEM

public static final int DB_JOIN_ITEM

A constant used to configure the system. It is used in the following locations:

• join(Dbc[],int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_JOIN_NOSORT

public static final int DB_JOIN_NOSORT

A constant used to configure the system. It is used in the following locations:

• join(Dbc[],int)

DB_KEYFIRST

public static final int DB_KEYFIRST

A constant used to configure the system. It is used in the following locations:

• Dbc.put(Dbt,Dbt,int)

DB_KEYLAST

public static final int DB_KEYLAST

A constant used to configure the system. It is used in the following locations:

• Dbc.put(Dbt,Dbt,int)

DB_LAST

public static final int DB_LAST

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)

DB_LOCKDOWN

public static final int DB_LOCKDOWN

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_LOCK_DEFAULT

public static final int DB_LOCK_DEFAULT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_EXPIRE

public static final int DB_LOCK_EXPIRE

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_GET

public static final int DB_LOCK_GET

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_GET_TIMEOUT

public static final int DB_LOCK_GET_TIMEOUT

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_IREAD

public static final int DB_LOCK_IREAD

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_IWR

public static final int DB_LOCK_IWR

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_IWRITE

public static final int DB_LOCK_IWRITE

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_MAXLOCKS

public static final int DB_LOCK_MAXLOCKS

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_MINLOCKS

public static final int DB_LOCK_MINLOCKS

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_MINWRITE

public static final int DB_LOCK_MINWRITE

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_NOWAIT

public static final int DB_LOCK_NOWAIT

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockGet(int,int,Dbt,int)
• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_OLDEST

public static final int DB_LOCK_OLDEST

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_PUT

public static final int DB_LOCK_PUT

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_PUT_ALL

public static final int DB_LOCK_PUT_ALL

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_PUT_OBJ

public static final int DB_LOCK_PUT_OBJ

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_RANDOM

public static final int DB_LOCK_RANDOM

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOCK_READ

public static final int DB_LOCK_READ

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_TIMEOUT

public static final int DB_LOCK_TIMEOUT

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_WRITE

public static final int DB_LOCK_WRITE

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockVector(int,int,DbLockRequest[],int,int)

DB_LOCK_YOUNGEST

public static final int DB_LOCK_YOUNGEST

A constant used to configure the system. It is used in the following locations:

• DbEnv.setLockDetect(int)
• DbEnv.lockDetect(int,int)

DB_LOG_AUTOREMOVE

public static final int DB_LOG_AUTOREMOVE

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_MPOOL_NOFILE

public static final int DB_MPOOL_NOFILE

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setFlags(int,boolean)

DB_MULTIPLE

public static final int DB_MULTIPLE

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_MULTIPLE_KEY

public static final int DB_MULTIPLE_KEY

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_NEXT

public static final int DB_NEXT

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)
• DbEnv.txnRecover(int,int)

DB_NEXT_DUP

public static final int DB_NEXT_DUP

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_NEXT_NODUP

public static final int DB_NEXT_NODUP

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_NODUPDATA

public static final int DB_NODUPDATA

A constant used to configure the system. It is used in the following locations:

• put(DbTxn,Dbt,Dbt,int)
• Dbc.put(Dbt,Dbt,int)

DB_NOLOCKING

public static final int DB_NOLOCKING

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_NOMMAP

public static final int DB_NOMMAP

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)
• DbEnv.setFlags(int,boolean)

DB_NOORDERCHK

public static final int DB_NOORDERCHK

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

DB_NOOVERWRITE

public static final int DB_NOOVERWRITE

A constant used to configure the system. It is used in the following locations:

• put(DbTxn,Dbt,Dbt,int)

DB_NOPANIC

public static final int DB_NOPANIC

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_NOSYNC

public static final int DB_NOSYNC

A constant used to configure the system. It is used in the following locations:

• close(int)

DB_ORDERCHKONLY

public static final int DB_ORDERCHKONLY

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

DB_OVERWRITE

public static final int DB_OVERWRITE

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_PANIC_ENVIRONMENT

public static final int DB_PANIC_ENVIRONMENT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_POSITION

public static final int DB_POSITION

A constant used to configure the system. It is used in the following locations:

• Dbc.dup(int)

DB_PREV

public static final int DB_PREV

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)

DB_PREV_NODUP

public static final int DB_PREV_NODUP

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_PRINTABLE

public static final int DB_PRINTABLE

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

DB_PRIORITY_DEFAULT

public static final int DB_PRIORITY_DEFAULT

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setPriority(int)

DB_PRIORITY_HIGH

public static final int DB_PRIORITY_HIGH

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setPriority(int)

DB_PRIORITY_LOW

public static final int DB_PRIORITY_LOW

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setPriority(int)

DB_PRIORITY_VERY_HIGH

public static final int DB_PRIORITY_VERY_HIGH

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setPriority(int)

DB_PRIORITY_VERY_LOW

public static final int DB_PRIORITY_VERY_LOW

A constant used to configure the system. It is used in the following locations:

• DbMpoolFile.setPriority(int)

DB_PRIVATE

public static final int DB_PRIVATE

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_RDONLY

public static final int DB_RDONLY

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

DB_RECNUM

public static final int DB_RECNUM

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_RECORDCOUNT

public static final int DB_RECORDCOUNT

DB_RECOVER

public static final int DB_RECOVER

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)
• DbEnv.setFeedbackHandler(DbEnvFeedbackHandler)
• DbEnvFeedbackHandler.feedback(DbEnv,int,int)

DB_RECOVER_FATAL

public static final int DB_RECOVER_FATAL

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_REGION_INIT

public static final int DB_REGION_INIT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_RENUMBER

public static final int DB_RENUMBER

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_REP_CLIENT

public static final int DB_REP_CLIENT

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationStart(Dbt,int)

DB_REP_ISPERM

public static final int DB_REP_ISPERM

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

DB_REP_LOGSONLY

public static final int DB_REP_LOGSONLY

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationStart(Dbt,int)

DB_REP_MASTER

public static final int DB_REP_MASTER

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationStart(Dbt,int)

DB_REP_NOBUFFER

public static final int DB_REP_NOBUFFER

A constant used to configure the system. It is used in the following locations:

• DbEnv.setReplicationTransport(int,DbRepTransport)
• DbRepTransport.send(DbEnv,Dbt,Dbt,DbLsn,int,int)

DB_REP_NOTPERM

public static final int DB_REP_NOTPERM

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)
• DbEnv.replicationProcessMessage(Dbt,Dbt,DbEnv.RepProcessMessage,DbLsn)

DB_REP_PERMANENT

public static final int DB_REP_PERMANENT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setReplicationTransport(int,DbRepTransport)
• DbRepTransport.send(DbEnv,Dbt,Dbt,DbLsn,int,int)

DB_REP_UNAVAIL

public static final int DB_REP_UNAVAIL

A constant used to configure the system. It is used in the following locations:

• DbEnv.replicationElect(int,int,int)

DB_REVSPLITOFF

public static final int DB_REVSPLITOFF

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_RMW

public static final int DB_RMW

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• join(Dbc[],int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_RPCCLIENT

public static final int DB_RPCCLIENT

A constant used to configure the system. It is used in the following locations:

• DbEnv(int)

DB_SALVAGE

public static final int DB_SALVAGE

A constant used to configure the system. It is used in the following locations:

• verify(String,String,java.io.OutputStream,int)

DB_SET

public static final int DB_SET

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)
• DbLogc.get(DbLsn,Dbt,int)

DB_SET_LOCK_TIMEOUT

public static final int DB_SET_LOCK_TIMEOUT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setTimeout(long,int)
• DbEnv.getTimeout(int)
• DbTxn.setTimeout(long,int)

DB_SET_RANGE

public static final int DB_SET_RANGE

A constant used to configure the system. It is used in the following locations:

• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_SET_RECNO

public static final int DB_SET_RECNO

A constant used to configure the system. It is used in the following locations:

• get(DbTxn,Dbt,Dbt,int)
• get(DbTxn,Dbt,Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,int)
• Dbc.get(Dbt,Dbt,Dbt,int)

DB_SET_TXN_TIMEOUT

public static final int DB_SET_TXN_TIMEOUT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setTimeout(long,int)
• DbEnv.getTimeout(int)
• DbTxn.setTimeout(long,int)

DB_SNAPSHOT

public static final int DB_SNAPSHOT

A constant used to configure the system. It is used in the following locations:

• setFlags(int)

DB_STAT_CLEAR

public static final int DB_STAT_CLEAR

A constant used to configure the system. It is used in the following locations:

• DbEnv.lockStat(int)
• DbEnv.logStat(int)
• DbEnv.memoryPoolStat(int)
• DbEnv.memoryPoolFileStat(int)
• DbEnv.replicationStat(int)
• DbEnv.txnStat(int)

DB_SYSTEM_MEM

public static final int DB_SYSTEM_MEM

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)

DB_THREAD

public static final int DB_THREAD

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)
• DbEnv.open(String,int,int)

DB_TIME_NOTGRANTED

public static final int DB_TIME_NOTGRANTED

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_TRUNCATE

public static final int DB_TRUNCATE

A constant used to configure the system. It is used in the following locations:

• open(DbTxn,String,String,int,int,int)

DB_TXN_NOSYNC

public static final int DB_TXN_NOSYNC

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)
• DbEnv.txnBegin(DbTxn,int)
• DbTxn.commit(int)

DB_TXN_NOT_DURABLE

public static final int DB_TXN_NOT_DURABLE

A constant used to configure the system. It is used in the following locations:

• setFlags(int)
• DbEnv.setFlags(int,boolean)

DB_TXN_NOWAIT

public static final int DB_TXN_NOWAIT

A constant used to configure the system. It is used in the following locations:

• DbEnv.txnBegin(DbTxn,int)

DB_TXN_SYNC

public static final int DB_TXN_SYNC

A constant used to configure the system. It is used in the following locations:

• DbEnv.txnBegin(DbTxn,int)
• DbTxn.commit(int)

DB_TXN_WRITE_NOSYNC

public static final int DB_TXN_WRITE_NOSYNC

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

DB_UPGRADE

public static final int DB_UPGRADE

A constant used to configure the system. It is used in the following locations:

• setFeedbackHandler(DbFeedbackHandler)
• DbFeedbackHandler.feedback(Db,int,int)

DB_USE_ENVIRON

public static final int DB_USE_ENVIRON

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)
• DbEnv.remove(String,int)

DB_USE_ENVIRON_ROOT

public static final int DB_USE_ENVIRON_ROOT

A constant used to configure the system. It is used in the following locations:

• DbEnv.open(String,int,int)
• DbEnv.remove(String,int)

DB_VERB_CHKPOINT

public static final int DB_VERB_CHKPOINT

A constant used to configure the system. It is used in the following locations:

• DbEnv.setVerbose(int,boolean)

DB_VERB_DEADLOCK

public static final int DB_VERB_DEADLOCK

A constant used to configure the system. It is used in the following locations:

• DbEnv.setVerbose(int,boolean)

DB_VERB_RECOVERY

public static final int DB_VERB_RECOVERY

A constant used to configure the system. It is used in the following locations:

• DbEnv.setVerbose(int,boolean)

DB_VERB_REPLICATION

public static final int DB_VERB_REPLICATION

A constant used to configure the system. It is used in the following locations:

• DbEnv.setVerbose(int,boolean)

DB_VERB_WAITSFOR

public static final int DB_VERB_WAITSFOR

A constant used to configure the system. It is used in the following locations:

• DbEnv.setVerbose(int,boolean)

DB_VERIFY

public static final int DB_VERIFY

A constant used to configure the system. It is used in the following locations:

• setFeedbackHandler(DbFeedbackHandler)
• DbFeedbackHandler.feedback(Db,int,int)

DB_VERSION_MAJOR

public static final int DB_VERSION_MAJOR

DB_VERSION_MINOR

public static final int DB_VERSION_MINOR

DB_VERSION_PATCH

public static final int DB_VERSION_PATCH

DB_WRITECURSOR

public static final int DB_WRITECURSOR

A constant used to configure the system. It is used in the following locations:

• cursor(DbTxn,int)

DB_XA_CREATE

public static final int DB_XA_CREATE

A constant used to configure the system. It is used in the following locations:

• Db(DbEnv,int)

DB_XIDDATASIZE

public static final int DB_XIDDATASIZE

A constant used to configure the system. It is used in the following locations:

• DbTxn.prepare(byte[])

DB_YIELDCPU

public static final int DB_YIELDCPU

A constant used to configure the system. It is used in the following locations:

• DbEnv.setFlags(int,boolean)

Constructor Detail

Db

public Db(DbEnv dbenv,
          int flags)
   throws DbException

The constructor creates a Db object that is the handle for a Berkeley DB database. The constructor allocates memory internally; calling the Db.close, Db.remove or Db.rename methods will free that memory.

Parameters:

dbenv - If no dbenv value is specified, the database is standalone; that is, it is not part of any Berkeley DB environment.

If a dbenv value is specified, the database is created within the specified Berkeley DB environment. The database access methods automatically make calls to the other subsystems in Berkeley DB based on the enclosing environment. For example, if the environment has been configured to use locking, the access methods will automatically acquire the correct locks when reading and writing pages of the database.

flags - must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

• Db.DB_XA_CREATE

  Instead of creating a standalone database, create a database intended to be accessed via applications running under a X/Open conformant Transaction Manager. The database will be opened in the environment specified by the OPENINFO parameter of the GROUPS section of the ubbconfig file. See the XA Resource Manager chapter in the Reference Guide for more information.

Throws:

DbException - Signals that an exception of some sort has occurred.

Method Detail

close

public void close(int flags)
           throws DbException

The Db.close method flushes any cached database information to disk, closes any open cursors, frees any allocated resources, and closes any underlying files.

The Db handle should not be closed while any other handle that refers to it is not yet closed; for example, database handles must not be closed while cursor handles into the database remain open, or transactions that include operations on the database have not yet been committed or aborted. Specifically, this includes Dbc and DbTxn handles.

Because key/data pairs are cached in memory, failing to sync the file with the Db.close or Db.sync method may result in inconsistent or lost information.

When called on a database that is the primary database for a secondary index, the primary database should be closed only after all secondary indices which reference it have been closed.

When multiple threads are using the Db concurrently, only a single thread may call the Db.close method.

The Db handle may not be accessed again after Db.close is called, regardless of its return.

Parameters:

flags - must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

• Db.DB_NOSYNC

  Do not flush cached information to disk. The Db.DB_NOSYNC flag is a dangerous option. It should be set only if the application is doing logging (with transactions) so that the database is recoverable after a system or application crash, or if the database is always generated from scratch after any system or application crash.

  It is important to understand that flushing cached information to disk only minimizes the window of opportunity for corrupted data. Although unlikely, it is possible for database corruption to happen if a system or application crash occurs while writing data to the database. To ensure that database corruption never occurs, applications must either: use transactions and logging with automatic recovery; use logging and application-specific recovery; or edit a copy of the database, and once all applications using the database have successfully called Db.close, atomically replace the original database with the updated copy.

Throws:

DbException

IllegalArgumentException - The Db.close method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

get_env

public DbEnv get_env()
              throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getDbEnv()

DbException

getDbEnv

public DbEnv getDbEnv()
               throws DbException

The Db.getDbEnv method returns the handle for the database environment underlying the database.

The Db.getDbEnv method may be called at any time during the life of the application.

Returns:

The Db.getDbEnv method returns the handle for the database environment underlying the database.

Throws:

DbException - Signals that an exception of some sort has occurred.

isEncrypted

public boolean isEncrypted()
                    throws DbException

The Db.isEncrypted method returns false if the underlying database files are encrypted and true if they are not.

The Db.isEncrypted method may not be called before the Db.open method has been called.

Returns:

The Db.isEncrypted method returns false if the underlying database files are encrypted and true if they are not.

Throws:

DbException - Signals that an exception of some sort has occurred.

open

public void open(DbTxn txnid,
                 String file,
                 String database,
                 int type,
                 int flags,
                 int mode)
          throws DbException,
                 FileNotFoundException,
                 DbDeadlockException,
                 DbLockNotGrantedException

The Db.open method opens the database represented by the file and database parameters for both reading and writing.

The currently supported Berkeley DB file formats (or access methods) are Btree, Hash, Queue, and Recno. The Btree format is a representation of a sorted, balanced tree structure. The Hash format is an extensible, dynamic hashing scheme. The Queue format supports fast access to fixed-length records accessed sequentially or by logical record number. The Recno format supports fixed- or variable-length records, accessed sequentially or by logical record number, and optionally backed by a flat text file.

Storage and retrieval for the Berkeley DB access methods are based on key/data pairs; see Dbt for more information.

Calling Db.open is a relatively expensive operation, and maintaining a set of open databases will normally be preferable to repeatedly opening and closing the database for each new query.

Environment Variables

If the database was opened within a database environment, the environment variable DB_HOME may be used as the path of the database environment home.

Db.open is affected by any database directory specified using the DbEnv.setDataDir method, or by setting the "set_data_dir" string in the environment's DB_CONFIG file.

If the file and dbenv parameters to Db.open are null, the environment variable TMPDIR may be used as a directory in which to create temporary backing files

Parameters:

database - optional, and allows applications to have multiple databases in a single file. Although no database parameter needs to be specified, it is an error to attempt to open a second database in a file that was not initially created using a database name. Further, the database parameter is not supported by the Queue format. Finally, when opening multiple databases in the same physical file, it is important to consider locking and memory cache issues; see Opening multiple databases in a single file for more information.

In-memory databases never intended to be preserved on disk may be created by setting both the file and database parameters to null. Note that in-memory databases can only ever be shared by sharing the single database handle that created them, in circumstances where doing so is safe.

file - used as the name of an underlying file that will be used to back the database.

In-memory databases never intended to be preserved on disk may be created by setting both the file and database parameters to null. Note that in-memory databases can only ever be shared by sharing the single database handle that created them, in circumstances where doing so is safe.

flags - must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

• Db.DB_AUTO_COMMIT

  Enclose the Db.open call within a transaction. If the call succeeds, the open operation will be recoverable. If the call fails, no database will have been created.

• Db.DB_CREATE

  Create the database. If the database does not already exist and the Db.DB_CREATE flag is not specified, the Db.open will fail.

• Db.DB_DIRTY_READ

  Support dirty reads; that is, read operations on the database may request the return of modified but not yet committed data. This flag must be specified on all Db handles used to perform dirty reads or database updates, otherwise requests for dirty reads may not be honored and the read may block.

• Db.DB_EXCL

  Return an error if the database already exists. The Db.DB_EXCL flag is only meaningful when specified with the Db.DB_CREATE flag.

• Db.DB_NOMMAP

  Do not map this database into process memory (see the DbEnv.setMemoryPoolMapSize method for further information).

• Db.DB_RDONLY

  Open the database for reading only. Any attempt to modify items in the database will fail, regardless of the actual permissions of any underlying files.

• Db.DB_THREAD

  Cause the Db handle returned by Db.open to be free-threaded; that is, usable by multiple threads within a single address space.

  Threading is always assumed in the Java API, so no special flags are required, and Berkeley DB functions will always behave as if the Db.DB_THREAD flag was specified.

• Db.DB_TRUNCATE

  Physically truncate the underlying file, discarding all previous databases it might have held. Underlying filesystem primitives are used to implement this flag. For this reason, it is applicable only to the file and cannot be used to discard databases within a file.

  The Db.DB_TRUNCATE flag cannot be lock or transaction-protected, and it is an error to specify it in a locking or transaction-protected environment.

mode - On UNIX systems or in IEEE/ANSI Std 1003.1 (POSIX) environments, all files created by the database open are created with mode mode (as described in chmod(2)) and modified by the process' umask value at the time of creation (see umask(2)). If mode is 0, the database open will use a default mode of readable and writable by both owner and group. On Windows systems, the mode parameter is ignored. The group ownership of created files is based on the system and directory defaults, and is not further specified by Berkeley DB.

txnid - If the operation is to be transaction-protected, (other than by specifying the Db.DB_AUTO_COMMIT flag), the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null. Note that transactionally protected operations on a Db handle requires the Db handle itself be transactionally protected during its open.

type - must be set to one of Db.DB_BTREE, Db.DB_HASH, Db.DB_QUEUE, Db.DB_RECNO, or Db.DB_UNKNOWN. If type is Db.DB_UNKNOWN, the database must already exist and Db.open will automatically determine its type. The Db.getDbType method may be used to determine the underlying type of databases opened using Db.DB_UNKNOWN.

Throws:

DbException - The Db.open method may fail and throw DbException, encapsulating one of the following non-zero errors:

The database cannot be opened without being first upgraded.

Db.DB_CREATE and Db.DB_EXCL were specified and the database exists.

A nonexistent re_source file was specified.

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.open method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.open method will fail and throw a DbLockNotGrantedException exception.

FileNotFoundException - If the file or directory does not exist, the Db.open method will fail and throw a FileNotFoundException exception.

IllegalArgumentException - The Db.open method will fail and throw a IllegalArgumentException exception if an unknown database type, page size, hash function, pad byte, byte order, or a flag value or parameter that is incompatible with the specified database was specified; the Db.DB_THREAD flag was specified and fast mutexes are not available for this architecture; the Db.DB_THREAD flag was specified to Db.open, but was not specified to the DbEnv.open call for the environment in which the Db handle was created; a backing flat text file was specified with either the Db.DB_THREAD flag or the provided database environment supports transaction processing; or if an invalid flag value or parameter was specified.

pget

public int pget(DbTxn txnid,
                Dbt key,
                Dbt pkey,
                Dbt data,
                int flags)
         throws DbException

Deprecated. Replaced in Berkeley DB 4.2 by get(DbTxn,Dbt,Dbt,Dbt,int)

DbException

remove

public void remove(String file,
                   String database,
                   int flags)
            throws DbException,
                   FileNotFoundException

The Db.remove method removes the database specified by the file and database parameters. If no database is specified, the underlying file represented by file is removed, incidentally removing all of the databases it contained.

Applications should never remove databases with open Db handles, or in the case of removing a file, when any database in the file has an open handle. For example, some architectures do not permit the removal of files with open system handles. On these architectures, attempts to remove databases currently in use by any thread of control in the system will fail.

The Db.remove method may not be called after calling the Db.open method on any Db handle. If the Db.open method has already been called on a Db handle, close the existing handle and create a new one before calling Db.remove.

The Db handle may not be accessed again after Db.remove is called, regardless of its return.

Environment Variables

If the database was opened within a database environment, the environment variable DB_HOME may be used as the path of the database environment home.

Db.remove is affected by any database directory specified using the DbEnv.setDataDir method, or by setting the "set_data_dir" string in the environment's DB_CONFIG file.

Parameters:

database - the database to be removed.

file - the physical file which contains the database(s) to be removed.

flags - currently unused, and must be set to 0.

Throws:

DbException - The Db.remove method may fail and throw DbException, encapsulating one of the following non-zero errors:

An attempt was made to remove the underlying file and a database in the file was currently open.

IllegalArgumentException - The Db.remove method will fail and throw a IllegalArgumentException exception if Db.remove called after Db.open was called; or if an invalid flag value or parameter was specified.

FileNotFoundException - If the file or directory does not exist, the Db.remove method will fail and throw a FileNotFoundException exception.

rename

public void rename(String file,
                   String database,
                   String newname,
                   int flags)
            throws DbException,
                   FileNotFoundException

The Db.rename method renames the database specified by the file and database parameters to newname. If no database is specified, the underlying file represented by file is renamed, incidentally renaming all of the databases it contained.

Applications should not rename databases that are currently in use. If an underlying file is being renamed and logging is currently enabled in the database environment, no database in the file may be open when the Db.rename method is called. In particular, some architectures do not permit renaming files with open handles. On these architectures, attempts to rename databases that are currently in use by any thread of control in the system will fail.

The Db.rename method may not be called after calling the Db.open method on any Db handle. If the Db.open method has already been called on a Db handle, close the existing handle and create a new one before calling Db.rename.

The Db handle may not be accessed again after Db.rename is called, regardless of its return.

Environment Variables

If the database was opened within a database environment, the environment variable DB_HOME may be used as the path of the database environment home.

Db.rename is affected by any database directory specified using the DbEnv.setDataDir method, or by setting the "set_data_dir" string in the environment's DB_CONFIG file.

Parameters:

database - the database to be removed.

file - the physical file which contains the database(s) to be removed.

flags - currently unused, and must be set to 0.

newname - the new name of the database or file.

Throws:

DbException - The Db.rename method may fail and throw DbException, encapsulating one of the following non-zero errors:

An attempt was made to rename the underlying file and a database in the file was currently open.

IllegalArgumentException - The Db.rename method will fail and throw a IllegalArgumentException exception if Db.rename called after Db.open was called; or if an invalid flag value or parameter was specified.

FileNotFoundException - If the file or directory does not exist, the Db.rename method will fail and throw a FileNotFoundException exception.

verify

public void verify(String file,
                   String database,
                   OutputStream outfile,
                   int flags)
            throws DbException,
                   FileNotFoundException

The Db.verify method verifies the integrity of all databases in the file specified by the file parameter, and optionally outputs the databases' key/data pairs to the file stream specified by the outfile parameter.

The Db.verify method does not perform any locking, even in Berkeley DB environments that are configured with a locking subsystem. As such, it should only be used on files that are not being modified by another thread of control.

The Db.verify method may not be called after the Db.open method is called.

The Db handle may not be accessed again after Db.verify is called, regardless of its return.

Environment Variables

If the database was opened within a database environment, the environment variable DB_HOME may be used as the path of the database environment home.

Db.verify is affected by any database directory specified using the DbEnv.setDataDir method, or by setting the "set_data_dir" string in the environment's DB_CONFIG file.

Parameters:

database - the database in file on which the database checks for btree and duplicate sort order and for hashing are to be performed. See the Db.DB_ORDERCHKONLY flag for more information.

The database parameter must be set to null except when the Db.DB_ORDERCHKONLY flag is set.

file - the physical file in which the databases to be verified are found.

flags - must be set to 0 or the following value:

• Db.DB_SALVAGE

  Write the key/data pairs from all databases in the file to the file stream named in the outfile parameter. The output format is the same as that specified for the db_dump utility, and can be used as input for the db_load utility.

  Because the key/data pairs are output in page order as opposed to the sort order used by db_dump, using Db.verify to dump key/data pairs normally produces less than optimal loads for Btree databases.

In addition, the following flags may be set by bitwise inclusively OR'ing them into the flags parameter:

• Db.DB_AGGRESSIVE

  Output all the key/data pairs in the file that can be found. By default, Db.verify does not assume corruption. For example, if a key/data pair on a page is marked as deleted, it is not then written to the output file. When Db.DB_AGGRESSIVE is specified, corruption is assumed, and any key/data pair that can be found is written. In this case, key/data pairs that are corrupted or have been deleted may appear in the output (even if the file being salvaged is in no way corrupt), and the output will almost certainly require editing before being loaded into a database.

• Db.DB_PRINTABLE

  When using the Db.DB_SALVAGE flag, if characters in either the key or data items are printing characters (as defined by isprint(3)), use printing characters to represent them. This flag permits users to use standard text editors and tools to modify the contents of databases or selectively remove data from salvager output.

  Note: different systems may have different notions about what characters are considered printing characters, and databases dumped in this manner may be less portable to external systems.

• Db.DB_NOORDERCHK

  Skip the database checks for btree and duplicate sort order and for hashing.

  The Db.verify method normally verifies that btree keys and duplicate items are correctly sorted, and hash keys are correctly hashed. If the file being verified contains multiple databases using differing sorting or hashing algorithms, some of them must necessarily fail database verification because only one sort order or hash function can be specified before Db.verify is called. To verify files with multiple databases having differing sorting orders or hashing functions, first perform verification of the file as a whole by using the Db.DB_NOORDERCHK flag, and then individually verify the sort order and hashing function for each database in the file using the Db.DB_ORDERCHKONLY flag.

• Db.DB_ORDERCHKONLY

  Perform the database checks for btree and duplicate sort order and for hashing, skipped by Db.DB_NOORDERCHK.

  When this flag is specified, a database parameter should also be specified, indicating the database in the physical file which is to be checked. This flag is only safe to use on databases that have already successfully been verified using Db.verify with the Db.DB_NOORDERCHK flag set.

outfile - an optional file stream to which the databases' key/data pairs are written.

Throws:

DbException

FileNotFoundException - If the file or directory does not exist, the Db.verify method will fail and throw a FileNotFoundException exception.

IllegalArgumentException - The Db.verify method will fail and throw a IllegalArgumentException exception if Db.verify was called after Db.open; or if an invalid flag value or parameter was specified.

set_cachesize

public void set_cachesize(int gbytes,
                          int bytes,
                          int ncache)
                   throws DbException

Deprecated. Replaced in Berkeley DB 4.2 by setCacheSize(long,int)

DbException

set_errcall

public void set_errcall(DbErrcall db_errcall_fcn)

Deprecated. Replaced in Berkeley DB 4.2 by setErrorHandler(DbErrorHandler)

setErrorHandler

public void setErrorHandler(DbErrorHandler db_errcall_fcn)
                     throws DbException

When an error occurs in the Berkeley DB library, an exception is thrown. In some cases, however, the errno value may be insufficient to completely describe the cause of the error, especially during initial application debugging.

The DbEnv.setErrorHandler and Db.setOnError methods are used to enhance the mechanism for reporting error messages to the application. The DbEnv.setErrorHandler and Db.setOnError methods must be called with a single object parameter. The object's class must implement the DbErrorHandler interface.

In some cases, when an error occurs, Berkeley DB will invoke the object's errcall() method with two parameters; the first is the prefix string (as previously set by Db.setErrorPrefix or DbEnv.setErrorPrefix), the second will be an error message string. It is up to this method to display the message in an appropriate manner.

Alternatively, you can use the DbEnv.setErrorStream and Db.setErrorStream methods to display the additional information via an output stream. You should not mix these approaches.

This error-logging enhancement does not slow performance or significantly increase application size, and may be run during normal operation as well as during application debugging.

For Db handles opened inside of Berkeley DB environments, calling the Db.setOnError method affects the entire environment and is equivalent to calling the DbEnv.setErrorHandler method.

The Db.setOnError method may be called at any time during the life of the application.

Parameters:

db_errcall_fcn - the application-specified error reporting function. The function takes two parameters:

The errpfx parameter is the prefix string (as previously set by Db.setErrorPrefix or DbEnv.setErrorPrefix).

The msg parameter is the error message string.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_errpfx

public String get_errpfx()

Deprecated. As of Berkeley DB 4.2, replaced by getErrorPrefix()

getErrorPrefix

public String getErrorPrefix()

The Db.getErrorPrefix method returns the error prefix.

The Db.getErrorPrefix method may be called at any time during the life of the application.

Returns:

The Db.getErrorPrefix method returns the error prefix.

set_errpfx

public void set_errpfx(String errpfx)

Deprecated. As of Berkeley DB 4.2, replaced by setErrorPrefix(String)

setErrorPrefix

public void setErrorPrefix(String errpfx)

Set the prefix string that appears before error messages issued by Berkeley DB.

For Db handles opened inside of Berkeley DB environments, calling the Db.setErrorPrefix method affects the entire environment and is equivalent to calling the DbEnv.setErrorPrefix method.

The Db.setErrorPrefix method may be called at any time during the life of the application.

Parameters:

errpfx - the application-specified error prefix for additional error messages.

set_error_stream

public void set_error_stream(OutputStream stream)

Deprecated. As of Berkeley DB 4.2, replaced by setErrorStream(java.io.OutputStream)

setErrorStream

public void setErrorStream(OutputStream stream)

When an error occurs in the Berkeley DB library, an exception is thrown. In some cases, however, the error information known to the Java layer may be insufficient to completely describe the cause of the error, especially during initial application debugging.

The DbEnv.setErrorStream and Db.setErrorStream methods are used to enhance the mechanism for reporting error messages to the application by setting a OutputStream to be used for displaying additional Berkeley DB error messages. In some cases, when an error occurs, Berkeley DB will output an additional error message to the specified stream.

The error message will consist of the prefix string and a colon (":") (if a prefix string was previously specified using DbEnv.setErrorPrefix), an error string, and a trailing <newline> character.

Alternatively, you can use the DbEnv.setErrorHandler method to capture the additional error information in a way that does not use output streams. You should not mix these approaches.

This error-logging enhancement does not slow performance or significantly increase application size, and may be run during normal operation as well as during application debugging.

For Db handles opened inside of Berkeley DB environments, calling the Db.setErrorStream method affects the entire environment and is equivalent to calling the DbEnv.setErrorStream method.

Parameters:

stream - the application-specified output stream to be used for additional error information.

set_feedback

public void set_feedback(DbFeedback feedback)
                  throws DbException

Deprecated. Replaced in Berkeley DB 4.2 by setFeedbackHandler(DbFeedbackHandler)

DbException

setPanicHandler

public void setPanicHandler(DbPanicHandler db_panic_fcn)
                     throws DbException

Errors can occur in the Berkeley DB library where the only solution is to shut down the application and run recovery (for example, if Berkeley DB is unable to allocate heap memory). In such cases, the Berkeley DB methods will throw a DbRunRecoveryException. It is often easier to simply exit the application when such errors occur rather than gracefully return up the stack. The Db.setPanic method specifies a function to be called when DbRunRecoveryException is about to be thrown from a Berkeley DB method.

For Db handles opened inside of Berkeley DB environments, calling the Db.setPanic method affects the entire environment and is equivalent to calling the DbEnv.setPanicHandler method.

The Db.setPanic method may be called at any time during the life of the application.

Parameters:

db_panic_fcn - the application-specified function called in the case of a database environment panic. The function takes two arguments:

The dbenv parameter is the enclosing database environment handle.

The e parameter is the DbException that would have been thrown to the calling method.

Throws:

DbException - Signals that an exception of some sort has occurred.

associate

public void associate(DbTxn txnid,
                      Db secondary,
                      DbSecondaryKeyCreate callback,
                      int flags)
               throws DbException

DbException

cursor

public Dbc cursor(DbTxn txnid,
                  int flags)
           throws DbException

The Db.cursor method returns a created database cursor.

Parameters:

flags - must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

• Db.DB_DIRTY_READ

  All read operations performed by the cursor may return modified but not yet committed data. Silently ignored if the Db.DB_DIRTY_READ flag was not specified when the underlying database was opened.

• Db.DB_WRITECURSOR

  Specify that the cursor will be used to update the database. The underlying database environment must have been opened using the Db.DB_INIT_CDB flag.

txnid - If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null. To transaction-protect cursor operations, cursors must be opened and closed within the context of a transaction, and the txnid parameter specifies the transaction context in which the cursor may be used.

Returns:

The Db.cursor method throws an exception that encapsulates a non-zero error value on failure.

Throws:

DbException - The Db.cursor method may fail and throw DbException, encapsulating one of the following non-zero errors:

IllegalArgumentException - The Db.cursor method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

del

public int del(DbTxn txnid,
               Dbt key,
               int flags)
        throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by delete(DbTxn,Dbt,int)

DbException

delete

public int delete(DbTxn txnid,
                  Dbt key,
                  int flags)
           throws DbException

The Db.delete method removes key/data pairs from the database. The key/data pair associated with the specified key is discarded from the database. In the presence of duplicate key values, all records associated with the designated key will be discarded.

When called on a database that has been made into a secondary index using the Db.associate method, the Db.delete method deletes the key/data pair from the primary database and all secondary indices.

Parameters:

key - The key Dbt operated on.

flags - must be set to 0 or the following value:

• Db.DB_AUTO_COMMIT

  Enclose the Db.delete call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes.

txnid - If the operation is to be transaction-protected, (other than by specifying the Db.DB_AUTO_COMMIT flag), the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null.

Returns:

• DB_NOTFOUND

  The Db.delete method will return Db.DB_NOTFOUND if the specified key is not in the database.

• DB_KEYEMPTY

  The Db.delete method will return Db.DB_KEYEMPTY if the database is a Queue or Recno database and the specified key exists, but was never explicitly created by the application or was later deleted.

Unless otherwise specified, the Db.delete method throws an exception that encapsulates a non-zero error value on failure.

Throws:

DbException - The Db.delete method may fail and throw DbException, encapsulating one of the following non-zero errors: An attempt was made to modify a read-only database.

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.delete method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.delete method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.delete method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

err

public void err(int error,
                String message)

The DbEnv.err, DbEnv.errx, Db.err and Db.errx methods provide error-messaging functionality for applications written using the Berkeley DB library.

The DbEnv.err method constructs an error message consisting of the following elements:

If no error callback function has been set using the DbEnv.setErrorHandler method, any prefix string specified using the DbEnv.setErrorPrefix method, followed by two separating characters: a colon and a <space> character.

Two separating characters: a colon and a <space> character.

The standard system or Berkeley DB library error string associated with the error value, as returned by the DbEnv.strerror method.

This constructed error message is then handled as follows:

If an error callback function has been set (see Db.setErrorHandler and DbEnv.setErrorHandler), that function is called with two parameters: any prefix string specified (see Db.setErrorPrefix and DbEnv.setErrorPrefix) and the error message.

If an OutputStream has been set (see DbEnv.setErrorStream and Db.setErrorStream), the error message is written to that stream.

If none of these output options has been configured, the error message is written to System.err, the standard error output stream.

Parameters:

error - the error value for which the DbEnv.err and Db.err methods will display a explanatory string.

message - an error message to display.

errx

public void errx(String message)

The DbEnv.errx and Db.errx methods perform identically to the DbEnv.err and Db.err methods, except that they do not append the final separator characters and standard error string to the error message.

Parameters:

message - an error message to display.

get

public int get(DbTxn txnid,
               Dbt key,
               Dbt data,
               int flags)
        throws DbException

The Db.get method retrieves key/data pairs from the database. The byte array and length of the data associated with the specified key are returned in the structure to which data refers.

In the presence of duplicate key values, Db.get will return the first data item for the designated key. Duplicates are sorted by insert order, except where this order has been overridden by cursor operations. Retrieval of duplicates requires the use of cursor operations. See Dbc.get for details.

When called on a database that has been made into a secondary index using the Db.associate method, the Db.get method returns the key from the secondary index and the data item from the primary database. In addition, the second method signature returns the key from the primary database. In databases that are not secondary indices, the second method signature will always fail.

Parameters:

data - The data Dbt operated on.

flags - must be set to 0 or one of the following values:

• Db.DB_CONSUME

  Return the record number and data from the available record closest to the head of the queue, and delete the record. The cursor will be positioned on the deleted record. The record number will be returned in key, as described in Dbt. The data will be returned in the data parameter. A record is available if it is not deleted and is not currently locked. The underlying database must be of type Queue for Db.DB_CONSUME to be specified.

• Db.DB_CONSUME_WAIT

  The Db.DB_CONSUME_WAIT flag is the same as the Db.DB_CONSUME flag, except that if the Queue database is empty, the thread of control will wait until there is data in the queue before returning. The underlying database must be of type Queue for Db.DB_CONSUME_WAIT to be specified.

  If lock or transaction timeouts have been specified, the Db.get method with the Db.DB_CONSUME_WAIT flag may return Db.DB_LOCK_NOTGRANTED. This failure, by itself, does not require the enclosing transaction be aborted.

• Db.DB_GET_BOTH

  Retrieve the key/data pair only if both the key and data match the arguments.

  When used with the second method signature version of this method on a secondary index handle, return the secondary key/primary key/data tuple only if both the primary and secondary keys match the arguments. It is an error to use the Db.DB_GET_BOTH flag with the first method signature version of this method and a secondary index handle.

• Db.DB_SET_RECNO

  Retrieve the specified numbered key/data pair from a database. Upon return, both the key and data items will have been filled in.

  The data field of the specified key must be a byte array large enough to hold a logical record number (that is, an int). This record number determines the record to be retrieved.

  For Db.DB_SET_RECNO to be specified, the underlying database must be of type Btree, and it must have been created with the DB_RECNUM flag.

In addition, the following flags may be set by bitwise inclusively OR'ing them into the flags parameter:

• Db.DB_AUTO_COMMIT

  Enclose the Db.get call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes. This flag may only be specified with the Db.DB_CONSUME and Db.DB_CONSUME_WAIT flags.

• Db.DB_DIRTY_READ

  Read modified but not yet committed data. Silently ignored if the Db.DB_DIRTY_READ flag was not specified when the underlying database was opened.

• Db.DB_MULTIPLE

  Return multiple data items in the buffer to which the data parameter refers.

  In the case of Btree or Hash databases, all of the data items associated with the specified key are entered into the buffer. In the case of Queue or Recno databases, all of the data items in the database, starting at, and subsequent to, the specified key, are entered into the buffer.

  The buffer to which the data parameter refers must be provided from user memory (see Db.DB_DBT_USERMEM). The buffer must be at least as large as the page size of the underlying database, aligned for unsigned integer access, and be a multiple of 1024 bytes in size. If the buffer size is insufficient, then upon return from the call the size field of the data parameter will have been set to an estimated buffer size, and a DbMemoryException is thrown. (The size is an estimate as the exact size needed may not be known until all entries are read. It is best to initially provide a relatively large buffer, but applications should be prepared to resize the buffer as necessary and repeatedly call the method.)

  The Db.DB_MULTIPLE flag may only be used alone, or with the Db.DB_GET_BOTH and Db.DB_SET_RECNO options. The Db.DB_MULTIPLE flag may not be used when accessing databases made into secondary indices using the Db.associate method.

  See DbMultipleDataIterator for more information.

• Db.DB_RMW

  Acquire write locks instead of read locks when doing the retrieval. Setting this flag can eliminate deadlock during a read-modify-write cycle by acquiring the write lock during the read part of the cycle so that another thread of control acquiring a read lock for the same item, in its own read-modify-write cycle, will not result in deadlock.

  Because the Db.get method will not hold locks across Berkeley DB calls in non-transactional operations, the Db.DB_RMW flag to the Db.get call is meaningful only in the presence of transactions.

key - The key Dbt operated on.

txnid - If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null.

Returns:

• DB_NOTFOUND

  The Db.get method will return Db.DB_NOTFOUND if the specified key is not in the database.

• DB_KEYEMPTY

  The Db.get method will return Db.DB_KEYEMPTY if the database is a Queue or Recno database and the specified key exists, but was never explicitly created by the application or was later deleted.

Unless otherwise specified, the Db.get method throws an exception that encapsulates a non-zero error value on failure.

Throws:

DbException - The Db.get method may fail and throw DbException, encapsulating one of the following non-zero errors:

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.get method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.get method will fail and throw a DbLockNotGrantedException exception.

DbLockNotGrantedException - If the Db.DB_CONSUME_WAIT flag was specified, lock or transaction timers were configured and the lock could not be granted before the wait-time expired, the Db.get method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.get method will fail and throw a IllegalArgumentException exception if a record number of 0 was specified; the Db.DB_THREAD flag was specified to the Db.open method and none of the Db.DB_DBT_MALLOC, Db.DB_DBT_REALLOC or Db.DB_DBT_USERMEM flags were set in the Dbt; the second method signature was called with a Db handle that does not refer to a secondary index; or if an invalid flag value or parameter was specified.

DbMemoryException - If the requested item could not be returned due to insufficient memory, the Db.get method will fail and throw a DbMemoryException exception.

get_byteswapped

public boolean get_byteswapped()
                        throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by isByteSwapped()

DbException

isByteSwapped

public boolean isByteSwapped()
                      throws DbException

The Db.isByteSwapped method returns false if the underlying database files were created on an architecture of the same byte order as the current one, and true if they were not (that is, big-endian on a little-endian machine, or vice versa). This information may be used to determine whether application data needs to be adjusted for this architecture or not.

The Db.isByteSwapped method may not be called before the Db.open method has been called.

Returns:

The Db.isByteSwapped method returns false if the underlying database files were created on an architecture of the same byte order as the current one, and true if they were not.

Throws:

DbException

IllegalArgumentException - The Db.isByteSwapped method will fail and throw a IllegalArgumentException exception if the method was called before Db.open was called; or if an invalid flag value or parameter was specified.

get_cachesize

public long get_cachesize()
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getCacheSize()

DbException

getCacheSize

public long getCacheSize()
                  throws DbException

The Db.getCacheSize method returns the size of the cache.

The Db.getCacheSize method may be called at any time during the life of the application.

Returns:

The Db.getCacheSize method returns the size of the cache.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_cachesize_ncache

public int get_cachesize_ncache()
                         throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getCacheSizeNcache()

DbException

getCacheSizeNcache

public int getCacheSizeNcache()
                       throws DbException

The DbEnv.getCacheSizeNcache method returns the number of caches.

The DbEnv.getCacheSizeNcache method may be called at any time during the life of the application.

Returns:

The DbEnv.getCacheSizeNcache method returns the number of caches.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_filename

public String get_filename()
                    throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getFileName()

DbException

getFileName

public String getFileName()
                   throws DbException

The Db.getFileName method returns the current filename.

The Db.getFileName method may be called at any time during the life of the application.

Returns:

The Db.getFileName method returns the current filename.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_dbname

public String get_dbname()
                  throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getDatabaseName()

DbException

getDatabaseName

public String getDatabaseName()
                       throws DbException

The Db.getDatabaseName method returns the current database name.

The Db.getDatabaseName method may be called at any time during the life of the application.

Returns:

The Db.getDatabaseName method returns the current database name.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_encrypt_flags

public int get_encrypt_flags()
                      throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getEncryptFlags()

DbException

getEncryptFlags

public int getEncryptFlags()
                    throws DbException

The Db.getEncryptFlags method returns the encryption flags.

The Db.getEncryptFlags method may be called at any time during the life of the application.

Returns:

The Db.getEncryptFlags method returns the encryption flags.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_flags

public int get_flags()
              throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getFlags()

DbException

getFlags

public int getFlags()
             throws DbException

The Db.getFlags method returns the current flags.

The Db.getFlags method may be called at any time during the life of the application.

Returns:

The Db.getFlags method returns the current flags.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_lorder

public int get_lorder()
               throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getByteOrder()

DbException

getByteOrder

public int getByteOrder()
                 throws DbException

The Db.getByteOrder method returns the database byte order; a byte order of 4,321 indicates a big endian order, and a byte order of 1,234 indicates a little endian order.

The Db.getByteOrder method may be called at any time during the life of the application.

Returns:

The Db.getByteOrder method returns the database byte order; a byte order of 4,321 indicates a big endian order, and a byte order of 1,234 indicates a little endian order.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_mpf

public DbMpoolFile get_mpf()
                    throws DbException

The Db.get_mpf method returns the handle for the cache file underlying the database.

The Db.get_mpf method may be called at any time during the life of the application.

Returns:

The Db.get_mpf method returns the handle for the cache file underlying the database.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_open_flags

public int get_open_flags()
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getOpenFlags()

DbException

getOpenFlags

public int getOpenFlags()
                 throws DbException

The Db.getOpenFlags method returns the current open method flags.

The Db.getOpenFlags method may not be called before the Db.open method has been called.

Returns:

The Db.getOpenFlags method returns the current open method flags.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_pagesize

public int get_pagesize()
                 throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getPageSize()

DbException

getPageSize

public int getPageSize()
                throws DbException

The Db.getPageSize method returns the page size.

The Db.getPageSize method may be called at any time during the life of the application.

Returns:

The Db.getPageSize method returns the page size.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_bt_minkey

public int get_bt_minkey()
                  throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getBtreeMinKey()

DbException

getBtreeMinKey

public int getBtreeMinKey()
                   throws DbException

The Db.getBtreeMinKey method returns the minimum number of key/data pairs intended to be stored on any single Btree leaf page.

The Db.getBtreeMinKey method may be called at any time during the life of the application.

Returns:

The Db.getBtreeMinKey method returns the minimum number of key/data pairs intended to be stored on any single Btree leaf page.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_h_ffactor

public int get_h_ffactor()
                  throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getHashFillFactor()

DbException

getHashFillFactor

public int getHashFillFactor()
                      throws DbException

The Db.getHashFillFactor method returns the hash table density.

The Db.getHashFillFactor method may be called at any time during the life of the application.

Returns:

The Db.getHashFillFactor method returns the hash table density.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_h_nelem

public int get_h_nelem()
                throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getHashNumElements()

DbException

getHashNumElements

public int getHashNumElements()
                       throws DbException

The Db.getHashNumElements method returns the estimate of the final size of the hash table.

The Db.getHashNumElements method may be called at any time during the life of the application.

Returns:

The Db.getHashNumElements method returns the estimate of the final size of the hash table.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_re_delim

public int get_re_delim()
                 throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getRecordDelimiter()

DbException

getRecordDelimiter

public int getRecordDelimiter()
                       throws DbException

The Db.getRecordDelimiter method returns the delimiting byte.

The Db.getRecordDelimiter method may be called at any time during the life of the application.

Returns:

The Db.getRecordDelimiter method returns the delimiting byte.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_re_len

public int get_re_len()
               throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getRecordLength()

DbException

getRecordLength

public int getRecordLength()
                    throws DbException

The Db.getRecordLength method returns the record length.

The Db.getRecordLength method may be called at any time during the life of the application.

Returns:

The Db.getRecordLength method returns the record length.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_re_pad

public int get_re_pad()
               throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getRecordPad()

DbException

getRecordPad

public int getRecordPad()
                 throws DbException

The Db.getRecordPad method returns the pad character.

The Db.getRecordPad method may be called at any time during the life of the application.

Returns:

The Db.getRecordPad method returns the pad character.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_re_source

public String get_re_source()
                     throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getRecordSource()

DbException

getRecordSource

public String getRecordSource()
                       throws DbException

The Db.getRecordSource method returns the source file.

The Db.getRecordSource method may be called at any time during the life of the application.

Returns:

The Db.getRecordSource method returns the source file.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_q_extentsize

public int get_q_extentsize()
                     throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getQueueExtentSize()

DbException

getQueueExtentSize

public int getQueueExtentSize()
                       throws DbException

The Db.getQueueExtentSize method returns the number of pages in an extent.

The Db.getQueueExtentSize method may be called at any time during the life of the application.

Returns:

The Db.getQueueExtentSize method returns the number of pages in an extent.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_flags_raw

public int get_flags_raw()
                  throws DbException

DbException

get_transactional

public boolean get_transactional()
                          throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by isTransactional()

DbException

isTransactional

public boolean isTransactional()
                        throws DbException

The Db.isTransactional method returns true if the Db handle has been opened in a transactional mode.

The Db.isTransactional method may be called at any time during the life of the application.

Returns:

The Db.isTransactional method returns true if the Db handle has been opened in a transactional mode.

Throws:

DbException - Signals that an exception of some sort has occurred.

get_type

public int get_type()
             throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by getDbType()

DbException

getDbType

public int getDbType()
              throws DbException

The Db.getDbType method returns the type of the underlying access method (and file format). The type value is one of Db.DB_BTREE, Db.DB_HASH, Db.DB_RECNO, or Db.DB_QUEUE. This value may be used to determine the type of the database after a return from Db.open with the type parameter set to Db.DB_UNKNOWN.

The Db.getDbType method may not be called before the Db.open method has been called.

Returns:

The Db.getDbType method returns the type of the underlying access method (and file format).

Throws:

DbException

IllegalArgumentException - The Db.getDbType method will fail and throw a IllegalArgumentException exception if the method was called before Db.open was called; or if an invalid flag value or parameter was specified.

join

public Dbc join(Dbc[] curslist,
                int flags)
         throws DbException

The Db.join method creates a specialized join cursor for use in performing equality or natural joins on secondary indices. For information on how to organize your data to use this functionality, see Equality join.

The Db.join method method is called using the Db handle of the primary database.

The join cursor supports only the Dbc.get and dbc_close cursor functions:

Iterates over the values associated with the keys to which each item in curslist was initialized. Any data value that appears in all items specified by the curslist parameter is then used as a key into the primary, and the key/data pair found in the primary is returned. The flags parameter must be set to 0 or the following value: In addition, the following flag may be set by bitwise inclusively OR'ing it into the flags parameter: Close the returned cursor and release all resources. (Closing the cursors in curslist is the responsibility of the caller.)

Parameters:

curslist - The curslist parameter contains a null terminated array of cursors. Each cursor must have been initialized to refer to the key on which the underlying database should be joined. Typically, this initialization is done by a Dbc.get call with the Db.DB_SET flag specified. Once the cursors have been passed as part of a curslist, they should not be accessed or modified until the newly created join cursor has been closed, or else inconsistent results may be returned.

Joined values are retrieved by doing a sequential iteration over the first cursor in the curslist parameter, and a nested iteration over each secondary cursor in the order they are specified in the curslist parameter. This requires database traversals to search for the current datum in all the cursors after the first. For this reason, the best join performance normally results from sorting the cursors from the one that refers to the least number of data items to the one that refers to the most. By default, Db.join does this sort on behalf of its caller.

For the returned join cursor to be used in a transaction-protected manner, the cursors listed in curslist must have been created within the context of the same transaction.

flags - must be set to 0 or the following value:

• Db.DB_JOIN_NOSORT

  Do not sort the cursors based on the number of data items to which they refer. If the data are structured so that cursors with many data items also share many common elements, higher performance will result from listing those cursors before cursors with fewer data items; that is, a sort order other than the default. The Db.DB_JOIN_NOSORT flag permits applications to perform join optimization prior to calling Db.join.

Returns:

The Db.join method throws an exception that encapsulates a non-zero error value on failure.

Throws:

DbException - The Db.join method may fail and throw DbException, encapsulating one of the following non-zero errors:

IllegalArgumentException - The Db.join method will fail and throw a IllegalArgumentException exception if cursor methods other than Dbc.get or Dbc.close were called; or if an invalid flag value or parameter was specified.

key_range

public void key_range(DbTxn txnid,
                      Dbt key,
                      DbKeyRange key_range,
                      int flags)
               throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by keyRange(DbTxn,Dbt,DbKeyRange,int)

DbException

keyRange

public void keyRange(DbTxn txnid,
                     Dbt key,
                     DbKeyRange key_range,
                     int flags)
              throws DbException

The Db.keyRange method returns an estimate of the proportion of keys that are less than, equal to, and greater than the specified key. The underlying database must be of type Btree.

The Db.keyRange method fills in a DbKeyRange object. The following data fields are available from the DbKeyRange object:

Values are in the range of 0 to 1; for example, if the field less is 0.05, 5% of the keys in the database are less than the key parameter. The value for equal will be zero if there is no matching key, and will be non-zero otherwise.

Parameters:

key - The key Dbt operated on.

key_range - The estimates are returned in the key_range parameter, which contains three elements of type double: less, equal, and greater. Values are in the range of 0 to 1; for example, if the field less is 0.05, 5% of the keys in the database are less than the key parameter. The value for equal will be zero if there is no matching key, and will be non-zero otherwise.

txnid - If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null. The Db.keyRange method does not retain the locks it acquires for the life of the transaction, so estimates may not be repeatable.

flags - currently unused, and must be set to 0.

Throws:

DbException - The Db.keyRange method may fail and throw DbException, encapsulating one of the following non-zero errors:

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.keyRange method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.keyRange method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.keyRange method will fail and throw a IllegalArgumentException exception if the underlying database was not of type Btree; or if an invalid flag value or parameter was specified.

get

public int get(DbTxn txnid,
               Dbt key,
               Dbt pkey,
               Dbt data,
               int flags)
        throws DbException

The Db.get method retrieves key/data pairs from the database. The byte array and length of the data associated with the specified key are returned in the structure to which data refers.

In the presence of duplicate key values, Db.get will return the first data item for the designated key. Duplicates are sorted by insert order, except where this order has been overridden by cursor operations. Retrieval of duplicates requires the use of cursor operations. See Dbc.get for details.

When called on a database that has been made into a secondary index using the Db.associate method, the Db.get method returns the key from the secondary index and the data item from the primary database. In addition, the second method signature returns the key from the primary database. In databases that are not secondary indices, the second method signature will always fail.

Parameters:

data - The data Dbt operated on.

flags - must be set to 0 or one of the following values:

• Db.DB_CONSUME

  Return the record number and data from the available record closest to the head of the queue, and delete the record. The cursor will be positioned on the deleted record. The record number will be returned in key, as described in Dbt. The data will be returned in the data parameter. A record is available if it is not deleted and is not currently locked. The underlying database must be of type Queue for Db.DB_CONSUME to be specified.

• Db.DB_CONSUME_WAIT

  The Db.DB_CONSUME_WAIT flag is the same as the Db.DB_CONSUME flag, except that if the Queue database is empty, the thread of control will wait until there is data in the queue before returning. The underlying database must be of type Queue for Db.DB_CONSUME_WAIT to be specified.

  If lock or transaction timeouts have been specified, the Db.get method with the Db.DB_CONSUME_WAIT flag may return Db.DB_LOCK_NOTGRANTED. This failure, by itself, does not require the enclosing transaction be aborted.

• Db.DB_GET_BOTH

  Retrieve the key/data pair only if both the key and data match the arguments.

  When used with the second method signature version of this method on a secondary index handle, return the secondary key/primary key/data tuple only if both the primary and secondary keys match the arguments. It is an error to use the Db.DB_GET_BOTH flag with the first method signature version of this method and a secondary index handle.

• Db.DB_SET_RECNO

  Retrieve the specified numbered key/data pair from a database. Upon return, both the key and data items will have been filled in.

  The data field of the specified key must be a byte array large enough to hold a logical record number (that is, an int). This record number determines the record to be retrieved.

  For Db.DB_SET_RECNO to be specified, the underlying database must be of type Btree, and it must have been created with the DB_RECNUM flag.

In addition, the following flags may be set by bitwise inclusively OR'ing them into the flags parameter:

• Db.DB_AUTO_COMMIT

  Enclose the Db.get call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes. This flag may only be specified with the Db.DB_CONSUME and Db.DB_CONSUME_WAIT flags.

• Db.DB_DIRTY_READ

  Read modified but not yet committed data. Silently ignored if the Db.DB_DIRTY_READ flag was not specified when the underlying database was opened.

• Db.DB_MULTIPLE

  Return multiple data items in the buffer to which the data parameter refers.

  In the case of Btree or Hash databases, all of the data items associated with the specified key are entered into the buffer. In the case of Queue or Recno databases, all of the data items in the database, starting at, and subsequent to, the specified key, are entered into the buffer.

  The buffer to which the data parameter refers must be provided from user memory (see Db.DB_DBT_USERMEM). The buffer must be at least as large as the page size of the underlying database, aligned for unsigned integer access, and be a multiple of 1024 bytes in size. If the buffer size is insufficient, then upon return from the call the size field of the data parameter will have been set to an estimated buffer size, and a DbMemoryException is thrown. (The size is an estimate as the exact size needed may not be known until all entries are read. It is best to initially provide a relatively large buffer, but applications should be prepared to resize the buffer as necessary and repeatedly call the method.)

  The Db.DB_MULTIPLE flag may only be used alone, or with the Db.DB_GET_BOTH and Db.DB_SET_RECNO options. The Db.DB_MULTIPLE flag may not be used when accessing databases made into secondary indices using the Db.associate method.

  See DbMultipleDataIterator for more information.

• Db.DB_RMW

  Acquire write locks instead of read locks when doing the retrieval. Setting this flag can eliminate deadlock during a read-modify-write cycle by acquiring the write lock during the read part of the cycle so that another thread of control acquiring a read lock for the same item, in its own read-modify-write cycle, will not result in deadlock.

  Because the Db.get method will not hold locks across Berkeley DB calls in non-transactional operations, the Db.DB_RMW flag to the Db.get call is meaningful only in the presence of transactions.

key - The key Dbt operated on.

pkey - the return key from the primary database.

txnid - If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null.

Returns:

• DB_NOTFOUND

  The Db.get method will return Db.DB_NOTFOUND if the specified key is not in the database.

• DB_KEYEMPTY

  The Db.get method will return Db.DB_KEYEMPTY if the database is a Queue or Recno database and the specified key exists, but was never explicitly created by the application or was later deleted.

Unless otherwise specified, the Db.get method throws an exception that encapsulates a non-zero error value on failure.

Throws:

DbException - The Db.get method may fail and throw DbException, encapsulating one of the following non-zero errors:

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.get method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.get method will fail and throw a DbLockNotGrantedException exception.

DbLockNotGrantedException - If the Db.DB_CONSUME_WAIT flag was specified, lock or transaction timers were configured and the lock could not be granted before the wait-time expired, the Db.get method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.get method will fail and throw a IllegalArgumentException exception if a record number of 0 was specified; the Db.DB_THREAD flag was specified to the Db.open method and none of the Db.DB_DBT_MALLOC, Db.DB_DBT_REALLOC or Db.DB_DBT_USERMEM flags were set in the Dbt; the second method signature was called with a Db handle that does not refer to a secondary index; or if an invalid flag value or parameter was specified.

DbMemoryException - If the requested item could not be returned due to insufficient memory, the Db.get method will fail and throw a DbMemoryException exception.

put

public int put(DbTxn txnid,
               Dbt key,
               Dbt data,
               int flags)
        throws DbException

The Db.put method stores key/data pairs in the database. The default behavior of the Db.put function is to enter the new key/data pair, replacing any previously existing key if duplicates are disallowed, or adding a duplicate data item if duplicates are allowed. If the database supports duplicates, the Db.put method adds the new data value at the end of the duplicate set. If the database supports sorted duplicates, the new data value is inserted at the correct sorted location.

Parameters:

flags - must be set to 0 or one of the following values:

• Db.DB_APPEND

  Append the key/data pair to the end of the database. For the Db.DB_APPEND flag to be specified, the underlying database must be a Queue or Recno database. The record number allocated to the record is returned in the specified key.

  There is a minor behavioral difference between the Recno and Queue access methods for the Db.DB_APPEND flag. If a transaction enclosing a Db.put operation with the Db.DB_APPEND flag aborts, the record number may be decremented (and later reallocated by a subsequent Db.DB_APPEND operation) by the Recno access method, but will not be decremented or reallocated by the Queue access method.

• Db.DB_NODUPDATA

  In the case of the Btree and Hash access methods, enter the new key/data pair only if it does not already appear in the database.

  The Db.DB_NODUPDATA flag may only be specified if the underlying database has been configured to support sorted duplicates. The Db.DB_NODUPDATA flag may not be specified to the Queue or Recno access methods.

• Db.DB_NOOVERWRITE

  Enter the new key/data pair only if the key does not already appear in the database. The Db.put method call with the Db.DB_NOOVERWRITE flag set will fail if the key already exists in the database, even if the database supports duplicates.

In addition, the following flag may be set by bitwise inclusively OR'ing it into the flags parameter:

• Db.DB_AUTO_COMMIT

  Enclose the Db.put call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes.

data - The data Dbt operated on.

key - The key Dbt operated on.

txnid - If the operation is to be transaction-protected, (other than by specifying the Db.DB_AUTO_COMMIT flag), the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null.

Returns:

Unless otherwise specified, the Db.put method throws an exception that encapsulates a non-zero error value on failure.

• DB_KEYEXIST

  The Db.put method will return Db.DB_KEYEXIST if Db.DB_NODUPDATA is set and the key/data pair already appears in the database.

• DB_KEYEXIST

  The Db.put method will return Db.DB_KEYEXIST if Db.DB_NOOVERWRITE is set and the key already appears in the database.

Throws:

DbException - The Db.put method may fail and throw DbException, encapsulating one of the following non-zero errors:

An attempt was made to modify a read-only database. A btree exceeded the maximum btree depth (255).

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.put method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.put method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.put method will fail and throw a IllegalArgumentException exception if a record number of 0 was specified; an attempt was made to add a record to a fixed-length database that was too large to fit; an attempt was made to do a partial put; an attempt was made to add a record to a secondary index; or if an invalid flag value or parameter was specified.

set_append_recno

public void set_append_recno(DbAppendRecno db_append_recno_fcn)
                      throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setAppendRecno(DbAppendRecno)

DbException

setAppendRecno

public void setAppendRecno(DbAppendRecno db_append_recno_fcn)
                    throws DbException

DbException

set_bt_compare

public void set_bt_compare(DbBtreeCompare bt_compare_fcn)
                    throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setBtreeCompare(DbBtreeCompare)

DbException

setBtreeCompare

public void setBtreeCompare(DbBtreeCompare bt_compare_fcn)
                     throws DbException

DbException

set_bt_maxkey

public void set_bt_maxkey(int maxkey)
                   throws DbException

DbException

set_bt_minkey

public void set_bt_minkey(int bt_minkey)
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setBtreeMinKey(int)

DbException

setBtreeMinKey

public void setBtreeMinKey(int bt_minkey)
                    throws DbException

Set the minimum number of key/data pairs intended to be stored on any single Btree leaf page.

This value is used to determine if key or data items will be stored on overflow pages instead of Btree leaf pages. For more information on the specific algorithm used, see Minimum keys per page. The bt_minkey value specified must be at least 2; if bt_minkey is not explicitly set, a value of 2 is used.

The Db.setBtreeMinKey method configures a database, not only operations performed using the specified Db handle.

The Db.setBtreeMinKey method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setBtreeMinKey will be ignored.

Description: Db.getBtreeMinKey

Parameters:

bt_minkey - the minimum number of key/data pairs intended to be stored on any single Btree leaf page.

Throws:

DbException

IllegalArgumentException - The Db.setBtreeMinKey method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_bt_prefix

public void set_bt_prefix(DbBtreePrefix bt_prefix_fcn)
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setBtreePrefix(DbBtreePrefix)

DbException

setBtreePrefix

public void setBtreePrefix(DbBtreePrefix bt_prefix_fcn)
                    throws DbException

DbException

set_cachesize

public void set_cachesize(long bytes,
                          int ncache)
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setCacheSize(long,int)

DbException

setCacheSize

public void setCacheSize(long bytes,
                         int ncache)
                  throws DbException

Set the size of the shared memory buffer pool -- that is, the cache. The cache should be the size of the normal working data set of the application, with some small amount of additional memory for unusual situations. (Note: the working set is not the same as the number of pages accessed simultaneously, and is usually much larger.)

The default cache size is 256KB, and may not be specified as less than 20KB. Any cache size less than 500MB is automatically increased by 25% to account for buffer pool overhead; cache sizes larger than 500MB are used as specified. The current maximum size of a single cache is 4GB. (All sizes are in powers-of-two, that is, 256KB is 2^32 not 256,000.) For information on tuning the Berkeley DB cache size, see Selecting a cache size.

It is possible to specify caches to Berkeley DB larger than 4GB and/or large enough they cannot be allocated contiguously on some architectures. For example, some releases of Solaris limit the amount of memory that may be allocated contiguously by a process. If ncache is 0 or 1, the cache will be allocated contiguously in memory. If it is greater than 1, the cache will be broken up into ncache equally sized, separate pieces of memory.

Because databases opened within Berkeley DB environments use the cache specified to the environment, it is an error to attempt to set a cache in a database created within an environment.

The Db.setCacheSize method may not be called after the Db.open method is called.

Parameters:

bytes - The size of the cache in bytes.

ncache - the number of caches to create.

Throws:

DbException

IllegalArgumentException - The Db.setCacheSize method will fail and throw a IllegalArgumentException exception if the specified cache size was impossibly small; called in a database environment; the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_dup_compare

public void set_dup_compare(DbDupCompare dup_compare_fcn)
                     throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setDuplicateCompare(DbDupCompare)

DbException

setDuplicateCompare

public void setDuplicateCompare(DbDupCompare dup_compare_fcn)
                         throws DbException

DbException

set_encrypt

public void set_encrypt(String passwd,
                        int flags)
                 throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setEncrypted(String,int)

DbException

setEncrypted

public void setEncrypted(String passwd,
                         int flags)
                  throws DbException

Set the password used by the Berkeley DB library to perform encryption and decryption.

Because databases opened within Berkeley DB environments use the password specified to the environment, it is an error to attempt to set a password in a database created within an environment.

The Db.setEncrypted method may not be called after the Db.open method is called.

Parameters:

flags - must be set to 0 or the following value:

• Db.DB_ENCRYPT_AES

  Use the Rijndael/AES (also known as the Advanced Encryption Standard and Federal Information Processing Standard (FIPS) 197) algorithm for encryption or decryption.

passwd - the password used to perform encryption and decryption.

Throws:

DbException - The Db.setEncrypted method may fail and throw DbException, encapsulating one of the following non-zero errors:

Cryptography is not available in this Berkeley DB release.

IllegalArgumentException - The Db.setEncrypted method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

setFeedbackHandler

public void setFeedbackHandler(DbFeedbackHandler db_feedback_fcn)
                        throws DbException

DbException

set_flags

public void set_flags(int flags)
               throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setFlags(int)

DbException

setFlags

public void setFlags(int flags)
              throws DbException

Configure a database. Calling Db.setFlags is additive; there is no way to clear flags.

The Db.setFlags method may not be called after the Db.open method is called.

Parameters:

flags - must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

General

The following flags may be specified for any Berkeley DB access method:

• Db.DB_CHKSUM

  Do checksum verification of pages read into the cache from the backing filestore. Berkeley DB uses the SHA1 Secure Hash Algorithm if encryption is configured and a general hash algorithm if it is not.

  Calling Db.setFlags with the Db.DB_CHKSUM flag only affects the specified Db handle (and any other Berkeley DB handles opened within the scope of that handle).

  If the database already exists when Db.open is called, the DB_CHKSUM flag will be ignored.

  If creating additional databases in a file, the checksum behavior specified must be consistent with the existing databases in the file or an error will be returned.

• Db.DB_ENCRYPT

  Encrypt the database using the cryptographic password specified to the DbEnv.setEncrypted or Db.setEncrypted methods.

  Calling Db.setFlags with the Db.DB_ENCRYPT flag only affects the specified Db handle (and any other Berkeley DB handles opened within the scope of that handle).

  If the database already exists when Db.open is called, the DB_ENCRYPT flag must be the same as the existing database or an error will be returned.

  If creating additional databases in a file, the encryption behavior specified must be consistent with the existing databases in the file or an error will be returned.

  Encrypted databases are not portable between machines of different byte orders, that is, encrypted databases created on big-endian machines cannot be read on little-endian machines, and vice versa.

• Db.DB_TXN_NOT_DURABLE

  If set, Berkeley DB will not write log records for this database. This means that updates of this database exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability); that is, database integrity will be maintained, but if the application or system fails, integrity will not persist. The database file must be verified and/or restored from backup after a failure. In order to ensure integrity after application shut down, the database handles must be closed without specifying Db.DB_NOSYNC, or all database changes must be flushed from the database environment cache using the DbEnv.txnCheckpoint method. All database handles for a single physical file must set Db.DB_TXN_NOT_DURABLE, including database handles for different databases in a physical file.

  Calling Db.setFlags with the Db.DB_TXN_NOT_DURABLE flag only affects the specified Db handle (and any other Berkeley DB handles opened within the scope of that handle).

Btree

The following flags may be specified for the Btree access method:

• Db.DB_DUP

  Permit duplicate data items in the database; that is, insertion when the key of the key/data pair being inserted already exists in the database will be successful. The ordering of duplicates in the database is determined by the order of insertion, unless the ordering is otherwise specified by use of a cursor operation.

  The Db.DB_DUPSORT flag is preferred to Db.DB_DUP for performance reasons. The Db.DB_DUP flag should only be used by applications wanting to order duplicate data items manually.

  Calling Db.setFlags with the Db.DB_DUP flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_DUP flag must be the same as the existing database or an error will be returned.

  It is an error to specify both Db.DB_DUP and Db.DB_RECNUM.

• Db.DB_DUPSORT

  Permit duplicate data items in the database; that is, insertion when the key of the key/data pair being inserted already exists in the database will be successful. The ordering of duplicates in the database is determined by the duplicate comparison function. A default lexical comparison will be used. It is an error to specify both Db.DB_DUPSORT and Db.DB_RECNUM.

  Calling Db.setFlags with the Db.DB_DUPSORT flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_DUPSORT flag must be the same as the existing database or an error will be returned.

• Db.DB_RECNUM

  Support retrieval from the Btree using record numbers. For more information, see the Db.DB_SET_RECNO flag to the Db.get and Dbc.get methods.

  Logical record numbers in Btree databases are mutable in the face of record insertion or deletion. See the Db.DB_RENUMBER flag in the Recno access method information for further discussion.

  Maintaining record counts within a Btree introduces a serious point of contention, namely the page locations where the record counts are stored. In addition, the entire database must be locked during both insertions and deletions, effectively single-threading the database for those operations. Specifying Db.DB_RECNUM can result in serious performance degradation for some applications and data sets.

  It is an error to specify both Db.DB_DUP and Db.DB_RECNUM.

  Calling Db.setFlags with the Db.DB_RECNUM flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_RECNUM flag must be the same as the existing database or an error will be returned.

• Db.DB_REVSPLITOFF

  Turn off reverse splitting in the Btree. As pages are emptied in a database, the Berkeley DB Btree implementation attempts to coalesce empty pages into higher-level pages in order to keep the database as small as possible and minimize search time. This can hurt performance in applications with cyclical data demands; that is, applications where the database grows and shrinks repeatedly. For example, because Berkeley DB does page-level locking, the maximum level of concurrency in a database of two pages is far smaller than that in a database of 100 pages, so a database that has shrunk to a minimal size can cause severe deadlocking when a new cycle of data insertion begins.

  Calling Db.setFlags with the Db.DB_REVSPLITOFF flag only affects the specified Db handle (and any other Berkeley DB handles opened within the scope of that handle).

Hash

The following flags may be specified for the Hash access method:

• Db.DB_DUP

  Permit duplicate data items in the database; that is, insertion when the key of the key/data pair being inserted already exists in the database will be successful. The ordering of duplicates in the database is determined by the order of insertion, unless the ordering is otherwise specified by use of a cursor operation.

  The Db.DB_DUPSORT flag is preferred to Db.DB_DUP for performance reasons. The Db.DB_DUP flag should only be used by applications wanting to order duplicate data items manually.

  Calling Db.setFlags with the Db.DB_DUP flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_DUP flag must be the same as the existing database or an error will be returned.

• Db.DB_DUPSORT

  Permit duplicate data items in the database; that is, insertion when the key of the key/data pair being inserted already exists in the database will be successful. The ordering of duplicates in the database is determined by the duplicate comparison function. A default lexical comparison will be used. It is an error to specify both Db.DB_DUPSORT and Db.DB_RECNUM.

  Calling Db.setFlags with the Db.DB_DUPSORT flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_DUPSORT flag must be the same as the existing database or an error will be returned.

Queue

There are no additional flags that may be specified for the Queue access method.

Recno

The following flags may be specified for the Recno access method:

• Db.DB_RENUMBER

  Specifying the Db.DB_RENUMBER flag causes the logical record numbers to be mutable, and change as records are added to and deleted from the database. For example, the deletion of record number 4 causes records numbered 5 and greater to be renumbered downward by one. If a cursor was positioned to record number 4 before the deletion, it will refer to the new record number 4, if any such record exists, after the deletion. If a cursor was positioned after record number 4 before the deletion, it will be shifted downward one logical record, continuing to refer to the same record as it did before.

  Using the Db.put or Dbc.put interfaces to create new records will cause the creation of multiple records if the record number is more than one greater than the largest record currently in the database. For example, creating record 28, when record 25 was previously the last record in the database, will create records 26 and 27 as well as 28. Attempts to retrieve records that were created in this manner will result in an error return of Db.DB_KEYEMPTY.

  If a created record is not at the end of the database, all records following the new record will be automatically renumbered upward by one. For example, the creation of a new record numbered 8 causes records numbered 8 and greater to be renumbered upward by one. If a cursor was positioned to record number 8 or greater before the insertion, it will be shifted upward one logical record, continuing to refer to the same record as it did before.

  For these reasons, concurrent access to a Recno database with the Db.DB_RENUMBER flag specified may be largely meaningless, although it is supported.

  Calling Db.setFlags with the Db.DB_RENUMBER flag affects the database, including all threads of control accessing the database.

  If the database already exists when Db.open is called, the DB_RENUMBER flag must be the same as the existing database or an error will be returned.

• Db.DB_SNAPSHOT

  This flag specifies that any specified re_source file be read in its entirety when Db.open is called. If this flag is not specified, the re_source file may be read lazily.

  Calling Db.setFlags with the Db.DB_SNAPSHOT flag only affects the specified Db handle (and any other Berkeley DB handles opened within the scope of that handle).

Throws:

DbException

IllegalArgumentException - The Db.setFlags method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

set_h_ffactor

public void set_h_ffactor(int h_ffactor)
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setHashFillFactor(int)

DbException

setHashFillFactor

public void setHashFillFactor(int h_ffactor)
                       throws DbException

Set the desired density within the hash table. If no value is specified, the fill factor will be selected dynamically as pages are filled.

The Db.setHashFillFactor method configures a database, not only operations performed using the specified Db handle.

The Db.setHashFillFactor method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setHashFillFactor will be ignored.

The density is an approximation of the number of keys allowed to accumulate in any one bucket, determining when the hash table grows or shrinks. If you know the average sizes of the keys and data in your data set, setting the fill factor can enhance performance. A reasonable rule computing fill factor is to set it to the following:

(pagesize - 32) / (average_key_size + average_data_size + 8)

Parameters:

h_ffactor - the desired density within the hash table.

Throws:

DbException

IllegalArgumentException - The Db.setHashFillFactor method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_h_hash

public void set_h_hash(DbHash h_hash_fcn)
                throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setHash(DbHash)

DbException

setHash

public void setHash(DbHash h_hash_fcn)
             throws DbException

DbException

set_h_nelem

public void set_h_nelem(int h_nelem)
                 throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setHashNumElements(int)

DbException

setHashNumElements

public void setHashNumElements(int h_nelem)
                        throws DbException

Set an estimate of the final size of the hash table.

In order for the estimate to be used when creating the database, the Db.setHashFillFactor method must also be called. If the estimate or fill factor are not set or are set too low, hash tables will still expand gracefully as keys are entered, although a slight performance degradation may be noticed.

The Db.setHashNumElements method configures a database, not only operations performed using the specified Db handle.

The Db.setHashNumElements method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setHashNumElements will be ignored.

Parameters:

h_nelem - an estimate of the final size of the hash table.

Throws:

DbException

IllegalArgumentException - The Db.setHashNumElements method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_lorder

public void set_lorder(int lorder)
                throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setByteOrder(int)

DbException

setByteOrder

public void setByteOrder(int lorder)
                  throws DbException

Set the byte order for integers in the stored database metadata. The host byte order of the machine where the Berkeley DB library was compiled will be used if no byte order is set.

The access methods provide no guarantees about the byte ordering of the application data stored in the database, and applications are responsible for maintaining any necessary ordering.

The Db.setByteOrder method configures a database, not only operations performed using the specified Db handle.

The Db.setByteOrder method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setByteOrder will be ignored.

If creating additional databases in a single physical file, information specified to Db.setByteOrder will be ignored and the byte order of the existing databases will be used.

Parameters:

lorder - The lorder parameter should represent the byte order as an integer; for example, big endian order is the number 4,321, and little endian order is the number 1,234.

Throws:

DbException

IllegalArgumentException - The Db.setByteOrder method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_pagesize

public void set_pagesize(long pagesize)
                  throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setPageSize(long)

DbException

setPageSize

public void setPageSize(long pagesize)
                 throws DbException

Set the size of the pages used to hold items in the database, in bytes. The minimum page size is 512 bytes, the maximum page size is 64K bytes, and the page size must be a power-of-two. If the page size is not explicitly set, one is selected based on the underlying filesystem I/O block size. The automatically selected size has a lower limit of 512 bytes and an upper limit of 16K bytes.

For information on tuning the Berkeley DB page size, see Selecting a page size.

The Db.setPageSize method configures a database, not only operations performed using the specified Db handle.

The Db.setPageSize method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setPageSize will be ignored.

If creating additional databases in a file, the page size specified must be consistent with the existing databases in the file or an error will be returned.

Parameters:

pagesize - The pagesize parameter sets the database page size.

Throws:

DbException

IllegalArgumentException - The Db.setPageSize method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_re_delim

public void set_re_delim(int re_delim)
                  throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setRecordDelimiter(int)

DbException

setRecordDelimiter

public void setRecordDelimiter(int re_delim)
                        throws DbException

Set the delimiting byte used to mark the end of a record in the backing source file for the Recno access method.

This byte is used for variable length records if the re_source file is specified. If the re_source file is specified and no delimiting byte was specified, <newline> characters (that is, ASCII 0x0a) are interpreted as end-of-record markers.

The Db.setRecordDelimiter method configures a database, not only operations performed using the specified Db handle.

The Db.setRecordDelimiter method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setRecordDelimiter will be ignored.

Parameters:

re_delim - the delimiting byte used to mark the end of a record.

Throws:

DbException

IllegalArgumentException - The Db.setRecordDelimiter method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_re_len

public void set_re_len(int re_len)
                throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setRecordLength(int)

DbException

setRecordLength

public void setRecordLength(int re_len)
                     throws DbException

For the Queue access method, specify that the records are of length re_len. For the Queue access method, the record length must be enough smaller than the database's page size that at least one record plus the database page's metadata information can fit on each database page.

For the Recno access method, specify that the records are fixed-length, not byte-delimited, and are of length re_len.

Any records added to the database that are less than re_len bytes long are automatically padded (see Db.setRecordPad for more information).

Any attempt to insert records into the database that are greater than re_len bytes long will cause the call to fail immediately and return an error.

The Db.setRecordLength method configures a database, not only operations performed using the specified Db handle.

The Db.setRecordLength method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setRecordLength will be ignored.

Parameters:

re_len - the length of a Queue or Recno database record, in bytes.

Throws:

DbException

IllegalArgumentException - The Db.setRecordLength method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_re_pad

public void set_re_pad(int re_pad)
                throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setRecordPad(int)

DbException

setRecordPad

public void setRecordPad(int re_pad)
                  throws DbException

Set the padding character for short, fixed-length records for the Queue and Recno access methods.

If no pad character is specified, <space> characters (that is, ASCII 0x20) are used for padding.

The Db.setRecordPad method configures a database, not only operations performed using the specified Db handle.

The Db.setRecordPad method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setRecordPad will be ignored.

Parameters:

re_pad - the pad character for fixed-length records for the Queue and Recno access methods.

Throws:

DbException

IllegalArgumentException - The Db.setRecordPad method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_re_source

public void set_re_source(String source)
                   throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setRecordSource(String)

DbException

setRecordSource

public void setRecordSource(String source)
                     throws DbException

Set the underlying source file for the Recno access method. The purpose of the source value is to provide fast access and modification to databases that are normally stored as flat text files.

The source parameter specifies an underlying flat text database file that is read to initialize a transient record number index. In the case of variable length records, the records are separated, as specified by Db.setRecordDelimiter. For example, standard UNIX byte stream files can be interpreted as a sequence of variable length records separated by <newline> characters.

In addition, when cached data would normally be written back to the underlying database file (for example, the Db.close or Db.sync methods are called), the in-memory copy of the database will be written back to the source file.

By default, the backing source file is read lazily; that is, records are not read from the file until they are requested by the application. If multiple processes (not threads) are accessing a Recno database concurrently, and are either inserting or deleting records, the backing source file must be read in its entirety before more than a single process accesses the database, and only that process should specify the backing source file as part of the Db.open call. See the Db.DB_SNAPSHOT flag for more information.

Reading and writing the backing source file specified by source cannot be transaction-protected because it involves filesystem operations that are not part of the Db transaction methodology. For this reason, if a temporary database is used to hold the records, it is possible to lose the contents of the source file, for example, if the system crashes at the right instant. If a file is used to hold the database, normal database recovery on that file can be used to prevent information loss, although it is still possible that the contents of source will be lost if the system crashes.

The source file must already exist (but may be zero-length) when Db.open is called.

It is not an error to specify a read-only source file when creating a database, nor is it an error to modify the resulting database. However, any attempt to write the changes to the backing source file using either the Db.sync or Db.close methods will fail, of course. Specify the Db.DB_NOSYNC flag to the Db.close method to stop it from attempting to write the changes to the backing file; instead, they will be silently discarded.

For all of the previous reasons, the source field is generally used to specify databases that are read-only for Berkeley DB applications; and that are either generated on the fly by software tools or modified using a different mechanism -- for example, a text editor.

The Db.setRecordSource method configures operations performed using the specified Db handle, not all operations performed on the underlying database.

The Db.setRecordSource method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setRecordSource must be the same as that historically used to create the database or corruption can occur.

Parameters:

source - The backing flat text database file for a Recno database.

Throws:

DbException

IllegalArgumentException - The Db.setRecordSource method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

set_q_extentsize

public void set_q_extentsize(int extentsize)
                      throws DbException

Deprecated. As of Berkeley DB 4.2, replaced by setQueueExtentSize(int)

DbException

setQueueExtentSize

public void setQueueExtentSize(int extentsize)
                        throws DbException

Set the size of the extents used to hold pages in a Queue database, specified as a number of pages. Each extent is created as a separate physical file. If no extent size is set, the default behavior is to create only a single underlying database file.

For information on tuning the extent size, see Selecting a extent size.

The Db.setQueueExtentSize method configures a database, not only operations performed using the specified Db handle.

The Db.setQueueExtentSize method may not be called after the Db.open method is called. If the database already exists when Db.open is called, the information specified to Db.setQueueExtentSize will be ignored.

Parameters:

extentsize - the number of pages in a Queue database extent.

Throws:

DbException

IllegalArgumentException - The Db.setQueueExtentSize method will fail and throw a IllegalArgumentException exception if the method was called after Db.open was called; or if an invalid flag value or parameter was specified.

stat

public Object stat(int flags)
            throws DbException

The Db.stat method creates a statistical structure and fills it with statistics for the database.

If the Db.DB_FAST_STAT flag has not been specified, the Db.stat method will access some of or all the pages in the database, incurring a severe performance penalty as well as possibly flushing the underlying buffer pool.

In the presence of multiple threads or processes accessing an active database, the information returned by Db.stat may be out-of-date.

If the database was not opened read-only and the Db.DB_FAST_STAT flag was not specified, the cached key and record numbers will be updated after the statistical information has been gathered.

The Db.stat method cannot be transaction-protected. For this reason, it should be called in a thread of control that has no open cursors or active transactions.

Hash Statistics

In the case of a Hash database, the statistics are returned in an instance of DbHashStat. The data fields are available from DbHashStat:

Btree and Recno Statistics

In the case of a Btree or Recno database, the statistics are returned in an instance of DbBtreeStat. The data fields are available from DbBtreeStat:

Queue Statistics

In the case of a Queue database, the statistics are returned in an instance of DbQueueStat. The data fields are available from DbQueueStat:

For convenience, the DbBtreeStat, DbHashStat and DbQueueStat classes have a toString method that lists all their data fields.

Parameters:

flags - must be set to 0 or one of the following values:

• Db.DB_FAST_STAT

  Return only the values which do not require traversal of the database.

  Among other things, this flag makes it possible for applications to request key and record counts without incurring the performance penalty of traversing the entire database. If the underlying database is of type Recno, or of type Btree and the database was created with the Db.DB_RECNUM flag, the count of keys will be exact. Otherwise, the count of keys will be the value saved the last time the database was traversed, or 0 if no count of keys has ever been made. If the underlying database is of type Recno, the count of data items will be exact, otherwise, the count of data items will be the value saved the last time the database was traversed, or 0 if no count of data items has ever been done.

Returns:

In the case of a Hash database, the statistics are returned in an instance of DbHashStat. In the case of a Btree or Recno database, the statistics are returned in an instance of DbBtreeStat. In the case of a Queue database, the statistics are returned in an instance of DbQueueStat.

Throws:

DbException - The Db.stat method may fail and throw DbException, encapsulating one of the following non-zero errors:

IllegalArgumentException - The Db.stat method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

sync

public void sync(int flags)
          throws DbException

The Db.sync method flushes any cached information to disk.

If the database is in memory only, the Db.sync method has no effect and will always succeed.

It is important to understand that flushing cached information to disk only minimizes the window of opportunity for corrupted data. Although unlikely, it is possible for database corruption to happen if a system or application crash occurs while writing data to the database. To ensure that database corruption never occurs, applications must either: use transactions and logging with automatic recovery; use logging and application-specific recovery; or edit a copy of the database, and once all applications using the database have successfully called Db.close, atomically replace the original database with the updated copy.

Parameters:

flags - currently unused, and must be set to 0.

Throws:

DbException - The Db.sync method may fail and throw DbException, encapsulating one of the following non-zero errors:

IllegalArgumentException - The Db.sync method will fail and throw a IllegalArgumentException exception if an invalid flag value or parameter was specified.

truncate

public int truncate(DbTxn txnid,
                    int flags)
             throws DbException

The Db.truncate method empties the database, discarding all records it contains. The number of records discarded from the database is returned.

It is an error to call the Db.truncate method on a database with open cursors.

Parameters:

flags - must be set to 0 or the following value:

• Db.DB_AUTO_COMMIT

  Enclose the Db.truncate call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes.

txnid - If the operation is to be transaction-protected, (other than by specifying the Db.DB_AUTO_COMMIT flag), the txnid parameter is a transaction handle returned from DbEnv.txnBegin; otherwise, null.

Returns:

The Db.truncate method returns the number of records discarded from the database.

Throws:

DbException

DbDeadlockException - If a transactional database environment operation was selected to resolve a deadlock, the Db.truncate method will fail and throw a DbDeadlockException exception.

DbLockNotGrantedException - If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time, the Db.truncate method will fail and throw a DbLockNotGrantedException exception.

IllegalArgumentException - The Db.truncate method will fail and throw a IllegalArgumentException exception if there are open cursors in the database; or if an invalid flag value or parameter was specified.

upgrade

public void upgrade(String file,
                    int flags)
             throws DbException

The Db.upgrade method upgrades all of the databases included in the file file, if necessary. If no upgrade is necessary, Db.upgrade always returns success.

Database upgrades are done in place and are destructive. For example, if pages need to be allocated and no disk space is available, the database may be left corrupted. Backups should be made before databases are upgraded. See Upgrading databases for more information.

Unlike all other database operations, Db.upgrade may only be done on a system with the same byte-order as the database.

Environment Variables

If the database was opened within a database environment, the environment variable DB_HOME may be used as the path of the database environment home.

Db.upgrade is affected by any database directory specified using the DbEnv.setDataDir method, or by setting the "set_data_dir" string in the environment's DB_CONFIG file.

Parameters:

file - the physical file containing the databases to be upgraded.

flags - must be set to 0 or the following value:

• Db.DB_DUPSORT

  This flag is only meaningful when upgrading databases from releases before the Berkeley DB 3.1 release.

  As part of the upgrade from the Berkeley DB 3.0 release to the 3.1 release, the on-disk format of duplicate data items changed. To correctly upgrade the format requires applications to specify whether duplicate data items in the database are sorted or not. Specifying the Db.DB_DUPSORT flag informs Db.upgrade that the duplicates are sorted; otherwise they are assumed to be unsorted. Incorrectly specifying the value of this flag may lead to database corruption.

  Further, because the Db.upgrade method upgrades a physical file (including all the databases it contains), it is not possible to use Db.upgrade to upgrade files in which some of the databases it includes have sorted duplicate data items, and some of the databases it includes have unsorted duplicate data items. If the file does not have more than a single database, if the databases do not support duplicate data items, or if all of the databases that support duplicate data items support the same style of duplicates (either sorted or unsorted), Db.upgrade will work correctly as long as the Db.DB_DUPSORT flag is correctly specified. Otherwise, the file cannot be upgraded using Db.upgrade; it must be upgraded manually by dumping and reloading the databases.

Throws:

DbException - The Db.upgrade method may fail and throw DbException, encapsulating one of the following non-zero errors:

The database cannot be upgraded by this version of the Berkeley DB software.

IllegalArgumentException - The Db.upgrade method will fail and throw a IllegalArgumentException exception if the database is not in the same byte-order as the system; or if an invalid flag value or parameter was specified.