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

Planning Database Security and Recovery
HP NonStop SQL/MX Installation and Management Guide—523723-004
5-15
Operations That Impact TMF Online Dumps
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TMF can retain online dumps of several generations of each file. The number of
generations retained depends on the RETAINDEPTH option of TMF configuration
parameters. Each generation of an online dump provides a starting point for a file
recovery operation. You gain greater reliability by keeping extra generations of
online dumps, but the site needs additional tape management for the online dumps
and audit trails.
For additional information about TMF recovery operations, see the TMF Operations
and Recovery Guide.
Operations That Impact TMF Online Dumps
Some SQL/MX operations impact TMF online dumps and require specific recovery
actions. For example, some operations invalidate TMF catalog entries, which
invalidates TMF online dumps. These SQL/MX operations delete or significantly alter
the file labels or the file contents.
To keep file recovery protection for these files, you must make new TMF online dumps
after any of these operations. Even if the operation fails to complete properly, file labels
or file contents might be affected. Plan to make new TMF online dumps even if one of
these operations is unsuccessful.
If you need to recover an affected table or index to a point before the SQL/MX
operation that invalidated the applicable dump, the TMF file recovery process might
require that you manually modify the online and audit dump entries in the TMF catalog
by using the TMF ALTER DUMPS or ADD DUMPS command. To preserve
consistency, this type of recovery must include not only the tables or indexes directly
affected but also all partitions of each table or index and all logically related objects in
the database.
For more information on making online dumps, see the TMF Operations and Recovery
Guide.
Caution. If the TMF catalog entries are incorrect and a problem occurs with the database, you
could lose the ability to use TMF file recovery operations to recover the database.
Caution. If a full recovery of a table is needed and the catalog is not going to be recovered,
the timestamps can cause inconsistencies that leave the table unusable.