SQL/MP Installation and Management Guide

Planning Database Security and Recovery
HP NonStop SQL/MP Installation and Management Guide—523353-004
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Backup Strategies
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For DDL statements, the catalog manager generates the appropriate number of
TMF transactions for the operations, reducing the overhead associated with TMF
audit trails and ensuring that the necessary locks are acquired for the operations.
These system-generated transactions occur regardless of the AUTOWORK
setting. For DDL statements issued within a user-defined TMF transaction, the
catalog manager does not initiate a system-defined TMF transaction.
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In addition to DDL statements, the COPY, PURGE, SECURE, and VERIFY
commands run within a TMF transaction when they operate on audited objects.
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You cannot run a DUP, LOAD, or PURGEDATA command within a user-defined
TMF transaction. You also cannot run a DDL statement or PURGE command
within a user-defined TMF transaction or with a statement embedded within a
program if the command operates on any nonaudited objects.
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You should not start a user-defined TMF transaction for the CREATE INDEX,
CREATE CONSTRAINT, DOWNGRADE CATALOG, MOVE PARTITION, or
UPDATE STATISTICS statement. For any of these operations, the catalog
manager automatically starts several TMF transactions. Certain portions of the
operation, however, are performed outside a TMF transaction unless you start one.
If performed on one or more large tables within a TMF transaction, the operation
could cause a TMF error.
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Only one user-defined TMF transaction can be active at a time in an SQLCI
session. You must commit or roll back the current user-defined transaction before
starting another.
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SQLCI provides an AUDITONLY option for the AUTOWORK ON command. If
AUDITONLY is in effect, SQLCI releases locks only on audited tables and holds
locks on nonaudited tables. You can use this option to hold locks on nonaudited
objects throughout a series of transactions and then use the UNLOCK TABLE
statement to release the locks on nonaudited tables. Using AUDITONLY helps
reduce the possibility of a deadlock between audited and nonaudited table locking.
AUTOWORK ON (without AUDITONLY) is the default.
Backup Strategies
Although you cannot determine whether you will ever need to use your backup tapes,
you should schedule backups regularly as a general precaution. In addition, you should
back up affected volumes or possibly the entire system when special events take
place, such as equipment changes, configuration changes, and major software
changes. You should also periodically back up to tape all nonaudited files, because no
other method of recovery is available for these files.
This subsection contains general guidelines for backing up SQL objects stored as
Guardian files, including information about these specific backup topics:
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Daily backups
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Periodic full backups
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Daily timestamp backups