SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Introduction to SQL/MX Database Management
HP NonStop SQL/MX Installation and Management Guide—523723-004
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Database Protection and Recovery
Database Protection and Recovery
An SQL/MX database is protected by:
•
The HP NonStop Transaction Management Facility (TMF), which audits database
changes and provides automatic recovery.
•
The HP NonStop Remote Database Facility (RDF), which monitors changes made
to a production database on a local (primary) system and maintains a copy of that
database on a remote (backup) system.
•
The Guardian Backup and Restore 2 utility, which you can use to perform tape
backups and restore SQL/MX objects. You can also save database creation and
loading scripts in OBEY command files or write an automated program to handle
TMF and backup and restore operations.
TMF provides automatic online recovery of audited SQL/MX objects and files by using
audit trails. A transaction currently in progress can be aborted if a failure or error
condition is detected. TMF terminates the transaction and restores the database to its
state before the beginning of the transaction. TMF provides two additional recovery
mechanisms:
•
Volume recovery, which recovers the database in the event of a disk crash or
system failure
•
File recovery, which reconstructs specific audited files when the current copies on
the data volume are not usable (for example, if a system or media failure
jeopardizes the consistency of one or more audited files).
The RDF subsystem enables you to use the backup database as a read-only resource
to balance the overall workload and improve response times. Activities at the backup
system can include querying the database, processing heavy batch-reporting loads,
and consolidating data from multiple sites into one central site. For more information,
see the RDF System Management Manual.
Use Backup and Restore 2 to back up to tape and restore to disk SQL/MX objects,
OSS program files, and other components, as required to properly recover your
database. Backup and Restore 2 uses BRCOM, the command-line user interface from
which you enter and manage BACKUP and RESTORE commands for SQL/MX and
OSS objects. For detailed information about the BRCOM command syntax, see the
Backup and Restore 2 Manual.
To back up and restore SQL/MP tables or other SQL/MP objects, you must use the
T9074 BACKUP and RESTORE utilities. For more information, see the SQL/MP
Installation and Management Guide, the SQL/MP Reference Manual, and the Guardian
Disk and Tape Utilities Reference Manual.
Utilities provide backup functionality for SQL executables and program modules stored
in OSS files. For more information about the utilities used with NonStop SQL/MX, see
the SQL/MX Reference Manual.