TMF Introduction (G06.26+)

TMF Overview
HP NonStop TMF Introduction—522414-002
1-12
Database Recovery
The audit-trail records contain both logical and physical audit information. The records
include before-images and after-images of audited data, and records of certain
transaction status information. Audit trails also include records about operations that
affect the physical structure of data files, such as block splits.
If the database is distributed over two or more nodes of a network, TMF maintains
separate audit trails on each node. Audit information for a distributed database is
shown at each node in Figure 1-8.
When a transaction is distributed over two or more systems, the before-images and
after-images are written to an audit trail on the node where the changed file resides.
For files partitioned across nodes, the before-images and after-images are written to
the audit trail on the node where the changed partition resides. Transaction status
records are written to the audit trails on all nodes that perform any work for a
transaction.
Figure 1-8. Distributed Audit Information
TMF
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\CHICAGO
\SEOUL
\LONDON
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