TMF Introduction (G06.26+)

Transaction Protection and Database Recovery
HP NonStop TMF Introduction—522414-002
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Online Dumps
Online Dumps
Online dumps preserve copies of audited database files in case of media failure or
other damage to a database such as an accidental purge, or in some cases, incorrect
application updates. Each online dump of a file provides an image of the file that can
be used by the file recovery process to reconstruct the file.
To support file recovery effectively, online dumps must be used with audit dumps
provided through automatic audit dumping, as shown in Figure 3-6. The online dump
provides an image of the database at a point in time; the audit dumps document all the
changes made to the database since that time.
HP recommends that you perform online dumps for critical production databases.
Online dumps are essential for most file recovery operations and ensure that the
database can be recovered to a consistent state.
Through online dumps, audited database files can be copied to tape or disk without
stopping active applications and without compromising the consistency of the
database. Online dumps can be made while transactions are being processed by the
applications.
Figure 3-6. Online and Audit Dumps for File Recovery
File Recovery
Online
Dump
Audit
Dump
VST061.vsd
Database
Audit