What is your db version? Default mechanism for complete refresh in 10g is delete/conventional insert, although you can switch back to using dbms_mview.refresh parameter atomic_refresh = false. For 9i it was truncate/insert/*+append*/ See previous posts on oracle-l //www.freelists.org/archives/oracle-l/01-2007/msg00666.html as well as asktom thread http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:15695764787749 Force means that you have fast if it is possible otherwise complete. So it is not clear what method you actually have - fast or complete? So basically you have two choices 1) refresh with "small" redo (truncate and insert /*+ append */) but have risk that there will be times when your MV wil have 0 rows. 2) refresh with "big" redo and always have full MVs 3) there is also third choice - using 2 alternate MVs with truncate, insert /*+ append */ and use the necessary one. I've explained it here http://www.gplivna.eu/papers/mat_views_search.htm Gints Plivna http://www.gplivna.eu 2007/6/14, Paul Vincent <Paul.Vincent@xxxxxxxxx>:
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
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