SQL/MP Installation and Management Guide

Planning Database Security and Recovery
HP NonStop SQL/MP Installation and Management Guide—523353-004
4-15
Guidelines for Online Dumps
Specifying TMF Attributes
Use these guidelines when specifying TMF attributes:
•
You can define a separate audit trail for each volume or audit more than one
volume in the same audit trail.
•
The volume or volumes containing the audit trails must have sufficient free space
to accommodate the extents required for the number of audit-trail files. If there is
insufficient space to create a new audit-trail file, transactions can be suspended
while the TMF operator dumps older audit-trail files to tape and frees enough
space to continue.
•
The amount of audit-trail data generated can vary depending on the setting of the
AUDITCOMPRESS attribute for the audited database files. Using
AUDITCOMPRESS saves system resources for update operations. Using NO
AUDITCOMPRESS enables you to read the TMF audit-trail files with complete
before and after images. AUDITCOMPRESS is the default for audited tables,
including catalog tables. (A CREATE INDEX operation that uses the WITH
SHARED ACCESS option always uses the NOAUDITCOMPRESS option.)
•
For a protection view, the AUDIT attribute value is automatically the same as the
value for the underlying table.
•
For an index, the AUDIT attribute value is automatically the same as the value for
the base table.
•
By altering the value of the AUDIT attribute for a base table, you also alter the
value for any dependent views and indexes.
For additional information on TMF configuration parameters and protection methods,
see the TMF Planning and Configuration Guide.
Guidelines for Online Dumps
Correct handling of online dumps is essential for effective functioning of file recovery
protection.
The TMF subsystem does not determine a schedule for online dumps. You must
decide on an online dump schedule that satisfies the needs of your business
operations. You can make online dumps without stopping your applications.
When scheduling online dumps, consider these guidelines:
•
You can send online dumps to disk or to tape. Dumping to tape uses one tape drive
completely and some system resources. You might not want to schedule online
dumps and backups (described under Backup Strategies on page 4-17) at the
same time or during the peak hours of application processing.
•
You should coordinate online dumps with application activity. For example, if your
site performs a series of batch processing or weekly updates at a particular time
each week, you should follow those operations with online dumps of database