Materialized views and redo
- From: "Paul Vincent" <Paul.Vincent@xxxxxxxxx>
- To: <Oracle-L@xxxxxxxxxxxxx>
- Date: Thu, 14 Jun 2007 09:48:19 +0100
On a system which otherwise generates very little redo (since about 99%
of all transactions are read-only, using only SELECTs), we have a
materialized view which is refreshed once an hour. This was introduced
to give a far better response time on a common query type which ran in
15 seconds without the view, but now runs in a second or less, using the
materialized view.
So far so good... but:
Every time the materialized view is refreshed, this generates about 40Mb
of redo activity, which means our archived logfiles area is now growing
at a rate of around 1Gb per day. For comparison, before the materialized
view was introduced, we only used to get about 50Mb of newly archived
log files per day.
Now, all this redo relates to the refreshing of an object which can
easily be regenerated by simply refreshing the view. There's no
conceivable scenario where this redo would ever be needed. So, is there
any way of completely "switching off" the generation of redo log entries
whenever the materialized view is auto-refreshed? This would save what's
becoming a bit of a disk-space headache.
Paul
Paul Vincent
Database Administrator
Information and Communication Technology
UCE Birmingham
paul.vincent@xxxxxxxxx
Other related posts:
