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Oracle Tips by Burleson |
AWR Settings: Changing
Interval and Retention
This script makes it simpler to change the
retention, but there are relatively few times when this should be
done. In general, the DBA should determine what frequency and
retention periods make the most sense for the specific database and
situation. In some cases, the DBA may be content with hourly
snapshots and seven days’ worth of history.
To further implement the self-tuning
database, it might be a good idea to vary the retention and
frequency of the AWR snapshots based on database load or some
criteria by which the DBA determines how busy the database is. The
frequencies could be shortened when there are problems and
lengthened when the problems are all under control.
When troubleshooting a problem that happens
less than once a week, DBAs may want to keep history around a bit
longer. If the problem is not readily apparent with the hourly
frequency because the data about the problem is lumped in with the
rest of the work going on over the whole hour, the DBA may want a
more frequent snapshot until the issue is resolved. Anytime these
settings are changed, the DBA must be sure to revisit space
allocation to make sure that the space will not run out so that data
collections are not missed due to lack of space.
The above book excerpt is from:
Oracle Wait Event Tuning
High Performance with Wait
Event Iinterface Analysis
ISBN 0-9745993-7-9
Stephen Andert
http://www.rampant-books.com/book_2004_2_wait_tuning.htm |
