SQL/MX 3.2 Management Manual (H06.25+, J06.14+)

Table Of Contents
Size Considerations
When determining the size requirements of TMF for NonStop SQL/MX, consider these guidelines:
DDL statements execute within system-defined TMF transactions, generating audit-trail entries.
DDL statements that refer to large tables can generate a large volume of audit-trail entries.
Transaction volume includes database use by both application programs and MXCI interactive
capabilities. The interactive volume might be minimal or might generate many audit-trail entries.
You should estimate INSERT, UPDATE, and DELETE transaction activity for each table and
view.
If you are performing parallel UPDATE and DELETE operations, consider increasing the amount
of audit trail space available to TMF. For more information, see the TMF Operations and
Recovery Guide.
If you have TMF configured to dump audit-trail files to tape, you should have at least two tape
drives available to prevent suspension of TMF transactions. If you have only one tape drive
and the drive fails, TMF suspends all new transactions if the maximum number of audit-trail
files that has been configured is reached.
Specifying TMF Attributes
When specifying TMF attributes, consider these guidelines:
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
TMF audit-trail files with complete before and after images. AUDITCOMPRESS is the default
for audited tables.
For more information, see the TMF Planning and Configuration Guide.
Guidelines for Creating and Managing Online Dumps
Correct handling of online dumps is essential for effective functioning of file recovery protection.
TMF does not determine a schedule for updating 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 working with online dumps, consider these guidelines:
When you create an online dump, in order to prevent it from being purged when a database
is dropped, ensure that the online dump contains partitions from multiple database tables.
You should never create an online dump that contains all the partitions of a single table and
no partitions from any other table. If you do not follow this practice, you will be unable to use
TMF to recover accidentally dropped database tables.
You can send online dumps to disk or tape. Dumping to tape uses one tape drive completely
and some system resources. You might not want to schedule online dumps and backups (see
“Using Backup and Restore 2 for SQL/MX Database Recovery” (page 60)) at the same time
or during 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 objects. Therefore, if a file recovery
50 Planning Database Security and Recovery