TMF Introduction (G06.26+)

Transaction Protection and Database Recovery
HP NonStop TMF Introduction—522414-002
3-11
Volume Recovery
Figure 3-5. Recovering a Database With Volume Recovery
Cache
Trx 2
Trx 4
Trx 3
Trx 1
Begin Transaction
Update Database
Commit Transaction
Trx 2
Begin Transaction
Update Database
Trx 3
Begin Transaction
Update Database
Commit Transaction
Trx 4
Begin Transaction
Update Database
Commit Transaction
...
Database Updates
Failure interrrupts the
writing of Transaction 2
database changes.
Before-images
and
After-images
Before-images
and
After-images
VST017.vsd
Volume Recov-
ery Process
$DB
Trx 2
Trx 1
$AUDIT
$AUDIT
$DB
Trx 1
Trx 3
Trx 4