Databases Reference
In-Depth Information
In the following screenshot, you can see that the checkpoint information was written to the
alert log:
In step 6, we query
V$SYSSTAT
to monitor some statistics related to the redo log files and
checkpoint. The result of the query is shown in the following screenshot:
If the number of started checkpoints is greater than the value of completed checkpoints
by more than one, in the first query, you need to enlarge redo log file size. In this situation,
checkpoints are not completed between log file switches, because the log file switches occur
too often, as log files are very small. Increasing redo log file size will limit the number of log
switches required, allowing checkpoints to complete between them.
A redo log switch should occur every 15 to 30 minutes (as
a rule of thumb); switching too often leads to performance
issues, whilst switching not often enough often may cause
a recovery operation to take longer.
