DPB Parameters

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The table below groups the DPB parameters by purpose.

System management

Description	Parameter
User validation parameters
User name	isc_dpb_user_name
Password	isc_dpb_password
Encrypted password	isc_dpb_password_enc
Database system encryption password	isc_dpb_sys_encrypt_password
System database administrator’s user name	isc_dpb_sys_user_name
Authorization key for a software license	isc_dpb_license
Database encryption key	isc_dpb_encrypt_key
Environmental control
Number of cache buffers	isc_dpb_num_buffers
dbkey context scope	isc_dpb_dbkey_scope
Force writes to the database to be done asynchronously or synchronously.	isc_dpb_force_write
Instructs server to include validation checks during a database restore.	isc_dpb_gbak_validate
Specify whether or not to reserve a small amount of space on each database page for holding backup versions of records when modifications are made.	isc_dpb_no_reserve
Specifies whether or not the database should be marked as damaged.	isc_dpb_damaged
Performs consistency checking of internal structures.	isc_dpb_verify
Specifies database space preallocation.	isc_dpb_preallocation
Use this parameter to request database preallocate information that is stored on the database header.	isc_info_dpb_preallocation
This directive initiates an online dump.	isc_dpb_online_dump
This parameter indicates that the current online dump files should be deleted and a full database dump executed (optional).	isc_dpb_old_overwrite
Specifies the name of an online dump file, up to 255 characters.	isc_dpb_old_file_name
This parameter specifies the number of pages for the online dump file (optional).	isc_dpb_old_file_size
This indicates the backup database to archive. The equivalent command line is: gbak-archive_database.	isc_dpb_archive_database
This parameter specifies the backup journals to archive. The equivalent command line is: gbak-archive_journals.	isc_dpb_archive_journals
This indicates the database to recover from archive. The equivalent command line is: gbak-archive_recover.	isc_dpb_archive_recover
This deletes all files in RDB$JOURNAL_ARCHIVES with RDB$ARCHIVE_SEQUENCE less than the requested sequence. The equivalent command line is: gfix-archive_sweep<n>.	isc_dpb_archive_sweep
Configures the maximum number of database dumps allowed in the archive. The equivalent command line is: gfix-archive_dumps<n>.	isc_dpb_archive_dumps
Recovers from archive until provided timestamp value. This is also known as Point-in-time-recovery. This is an optional argument. Full recovery will happen if this value is not provided.	isc_dpb_recover_until
Shadow control
Activates the database shadow, an optional, duplicate, in-sync copy of the database.	isc_dpb_activate_shadow
Deletes the database shadow.	isc_dpb_delete_shadow
Replay logging system control
Activates a replay logging system to keep track of all database calls.	isc_dpb_begin_log
Deactivates the replay logging system.	isc_dpb_quit_log
Character set and message file specification
Language-specific message file.	isc_dpb_lc_messages
Character set to be used.	isc_dpb_lc_ctype

The following table lists DPB parameters in alphabetical order. For each parameter, it lists its purpose, the length, in bytes, of any values passed with the parameter, and the value to pass.

Parameter	Purpose	Length	Value
isc_dpb_activate_shadow	Directive to activate the database shadow, which is an optional, duplicate, in-sync copy of the database.	1 (Ignored)	0 (Ignored)
isc_dpb_archive_database	Backup database to archive. The equivalent command line is:      gbak -archive_database	1	1
isc_dpb_archive_journals	Backup journals to archive. The equivalent command line is:      gbak -archive_journals	1	1
isc_dpb_archive_dumps	Configures the maximum number of database dumps allowed in the archive. The equivalent command-line is:      gfix -archive_dumps <n>	Number of bytes occupied by integer Value (1, 2 or 4)	Number of database dump files allowed in the archive directory. 0 indicates no limit.
isc_dpb_archive_recover	Recovers database from archive. The equivalent command line is:     gbak -archive_recover String specifying the name of an archived database dump file from the recovery folder, up to 255 characters.	Number of bytes in string	Archive database dump filename
isc_dpb_archive_sweep	Deletes all files in RDB$JOURNAL_ARCHIVES with RDB$ARCHIVE_SEQUENCE less than the requested sequence. The equivalent command line is:     gfix -archive_sweep <n>.	Number of bytes occupied by integer Value (1, 2 or 4)	Delete journal archives less than this Archive Sequence integer number
isc_dpb_damaged	Number signifying whether or not the database should be marked as damaged. 1 = mark as damaged 0 = do not mark as damaged	1	0 or 1
isc_dpb_dbkey_scope	Scope of dbkey context. 0 limits scope to the current transaction, 1 extends scope to the database session.	1	0 or 1
isc_dpb_delete_shadow	Directive to delete a database shadow that is no longer needed.	1 (Ignored)	0 (Ignored)
isc_dpb_encrypt_key	String encryption key, up to 255 ­characters	Number of bytes in string	String containing key
isc_dpb_force_write	Specifies whether database writes are synchronous or asynchronous. 0 = asynchronous; 1 = synchronous	1	0 or 1
isc_dpb_gbak_validate	Instructs server to include validation checks during a database restore.
isc_dpb_lc_ctype	String specifying the character set to be utilized	Number of bytes in string	String containing character set name
isc_dpb_lc_messages	String specifying a language-specific message file	Number of bytes in string	String containing message file name
isc_dpb_license	String authorization key for a software license	Number of bytes in string	String containing key
isc_dpb_no_reserve	Specifies whether or not a small amount of space on each database page is reserved for holding backup versions of records when modifications are made; keeps backup versions on the same page as the primary record to optimize update activity. 0 (default) = reserve space 1= do not reserve space	1	0 or 1
isc_dpb_ods_version_major	Creates database with specified major ODS version as the target version.	2-bytes Short integer	Value denoting the major ODS version number of the target database
isc_dpb_num_buffers	Number of database cache buffers to allocate for use with the database; default=2,048.	Number of bytes in the length indicator (1,2, or 4)	Number of ­buffers to ­allocate
isc_dpb_online_dump	Directive to initiate an online dump.	1	0 or 1
isc_dpb_old_overwrite	Indicates the current online dump files should be deleted and a full database dump executed (optional).	1	0 or 1
isc_dpb_old_file_name	String specifying the name of an online dump file, up to 255 characters.	Number of bytes in string	Dump file name string
isc_dpb_old_file_size	Number of pages for online dump file (optional)	Number of bytes for length indicator (1, 2, or 4)	Number of pages for dump length
isc_dpb_password	String password, up to 255 characters.	Number of bytes in string	String containing password
isc_dpb_password_enc	String encrypted password, up to 255 characters.	Number of bytes in string	String containing password
isc_dpb_preallocate	Specifies database preallocation. It is only recognized and processed by isc_create_database(). isc_attach_database() silently ignores isc_dpb_preallocate. Use the isc_info_db_preallocate database info parameter to request database preallocate information stored on the database header page.	4
isc_dpb_recover_until	Recovers from archive until provided timestamp value. This is also known as Point-in-time-recovery. This is an optional argument. Full recovery will happen if this value is not provided. Accepted Timestamp string format detailed in Formatting Dates for Input. For example: "2006-08-21 18:08:15"	Number of bytes in string	String indicating Timestamp, format
isc_dpb_set_db_sql_dialect	Number indicating the SQL dialect used by the client; used by the gfix utility to set the dialect in the database header page. Dialect 3 gives access to features introduced in InterBase XE.	1	1 - V5.x & V6 compatible 2 - diagnostic 3 - V6 only
isc_dpb_sql_dialect	Number indicating the SQL dialect used by the client. Dialect 3 gives access to features introduced in InterBase XE.	1	1 - V5.x & V6 compatible 2 - diagnostic 3 - V6 only
isc_dpb_sql_role_name	String login role name.	Number of bytes in string	String
isc_dpb_sys_encrypt_password	Database system encryption password (SEP), up to 255 characters.	Number of bytes in string	String containing SEP
isc_dpb_sys_user_name	String system DBA name, up to 255 characters.	Number of bytes in string	String containing SYSDBA name
isc_dpb_user_name	String user name, up to 255 characters.	Number of bytes in string	String containing user name

Some parameters, such as isc_dpb_delete_shadow, are directives that do not require additional parameters. Even so, you must still provide length and value bytes for these parameters. Set length to 1 and value to 0. InterBase ignores these parameter values, but they are required to maintain the format of the DPB.

Note:
With the InterBase service API, actions isc_action_svc_backup (isc_action_svc_restore) take new parameters, isc_spb_bkp_preallocate (isc_spb_res_preallocate), respectively. Both parameters take a 4-byte argument to specify the database preallocation in units of database pages. The service parameters have the same numeric value, but two symbolic constants are provided for source code clarity to show the proper intent.

See Also

• Adding Parameters to a DPB

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• Adding Parameters to a DPB