9.2 - Parallel Query Not Working
- From: David Aldridge <david@xxxxxxxxxxxxxxxxxx>
- To: Oracle List <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 28 Feb 2008 09:03:14 -0800 (PST)
On a 9.2.0.6 database on Solarix 64, which is created every day from a magical
SAN-based mirror process thing (excuse the tech talk), we alter a particular
table to a default degree of parallelsim of 12. A process which performs a full
scan of that table picks up the degree of 12 and completes in a couple of hours.
Later in the day we can no longer prompt the instance to give any
parallelism.
I've tried everything obvious ... setting parallel_adaptive_multiuser to
false, parallel max servers to 48, used hints, made sure the table's default
dop is 12, checked that PROCESSES is reasonably high (500+), that the server is
not very busy (less than 10 active sessions), ALTER SESSION FORCE PARALLEL
QUERY, but nothing we do will prompt PQ to be used on even the most simple
SELECT * FROM ... queries.
Any thoughts on this are much appreciated.
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