Data Consistency, Recovery, and Migration 4-43

Step 3: Roll Forward Log Records

Step 3: Roll Forward Log Records
The third step in fast recovery is to roll forward the logical log records that
werewritten after the most-recent checkpoint record. This action reproduces
all changes to the databases since the time of the last checkpoint, up to the
point where the uncontrolled shutdown occurred.Figure 4-6 illustrates this
step.
Figure4-6
Fast recovery,
step3
Fast Recovery: Step 3
OnLine rolls forward the logical log records written since the most-recent
checkpoint, reproducing the changes to the database since the checkpoint.
Records since the
checkpoint
Disk A
Logical log
Databasechanges since
the checkpoint rolled
forward