RE: query performance - getting started
- From: <Joel.Patterson@xxxxxxxxxxx>
- To: <Hemant.Chitale@xxxxxx>
- Date: Fri, 8 Apr 2011 08:19:58 -0400
Very good, I remember that now from the good 'ol days. Thx for the doc Ids.
Joel Patterson
Database Administrator
904 727-2546
________________________________
From: Chitale, Hemant Krishnarao [mailto:Hemant.Chitale@xxxxxx]
Sent: Friday, April 08, 2011 2:06 AM
To: Patterson, Joel
Cc: oracle-l@xxxxxxxxxxxxx
Subject: RE: query performance - getting started
You can check to see if the MV refresh really does a TRUNCATE. If you can
query and see data while the Refresh is running, then a DELETE-INSERT is being
done.
To revert to the 9i behaviour of TRUNCATE-INSERT , set ATOMIC_REFRESH to FALSE
in your DBMS_MVIEW.REFRESH call.
(See OracleSupport article Complete Refresh Read Consistency Behavior During
Refresh and Complete Refresh Performance as Influenced by the ATOMIC_REFRESH
Refresh Parameter [ID 553464.1]
)
You can also define the MV to use Parallel Query in the COMPLETE Refresh's.
(See OracleSupport article How to Refresh a Materialized View in Parallel [ID
577870.1] )
Hemant K Chitale
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Joel.Patterson@xxxxxxxxxxx
Sent: Thursday, April 07, 2011 8:51 PM
To: Joel.Patterson@xxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Cc: kylelf@xxxxxxxxx
Subject: RE: query performance - getting started
Query performance continued.
We have a very complicated Materialized view, and a view that utilizes the MV.
We cannot use Fast refresh - a complete refresh is necessary. The app can
decide when the view is refreshed, and can execute dbms_refresh when necessary.
Essentially all records are truncated, and the view is rebuilt as part of the
complete refresh. So, is this just as easy, efficient as any other method
such as Temp tables, Truncating a permanent table and re-inserting, or other?
Moving forward,
JP
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