TMF Introduction (G06.24+)

Transaction Protection and Database Recovery
HP NonStop Transaction Management Facility (TMF) Introduction—522414-001
3-2
Audit Trails
Audit Trails
An audit trail is a series of files that TMF uses to record sequential information about a
transaction’s changes to an audited file. Only TMF can rename, purge, or alter audit
trail files.
The disk volumes that contain audit trails are called active audit volumes. HP requires
that you place audit trail files and audited database files on separate disk volumes so
that the database files and audit trail files cannot be damaged by the same failure. The
volumes where audited database files reside are called data volumes.
Figure 3-1 illustrates the contents of audit records and associated database files for a
transaction that deposits $550 to the Lee checking account, and $100 to the Lee
savings account. In this figure, the checking and savings database files reside on
audited volumes on disks $DB1 and $DB2; the audit trail files reside on a separate
disk, $AUDIT.
Figure 3-1. Audit Trail Records
AA001002
TX1 (CHECKING)
BEFORE LEE $250
AFTER LEE $800
TX1 (SAVINGS)
BEFORE LEE $100
AFTER LEE $200
TX1 COMMIT
•
•
•
AA001001
$AUDIT
CHECKING
ADAMS
LEE
WOOD
$450
$800
$250
$DB1
$DB2
SAVINGS
BROWN
LEE
WHITE
$400
$200
$600
VST013.vsd