Parallel queries in RAC environment
- From: "James Barton" <james.barton@xxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 15 Oct 2008 14:03:43 +0100
4-node RAC, 10.2.0.3
I have a long-running batch process. I suspect that some of the queries
it contains would run faster with multiple read processes, and I'm
trying to test this out.
I've hinted the relevant queries with
/*+ parallel (table_alias 6) */
and I can see that six read processed do start. The problem is that they
are all on another instance than the original batch process. This
results in a lot of block swapping and I actually see a slight
degradation in performance. Currently I'm starting the batch process as
a scheduled job, and the job class it belongs to has a service that is
available on only one instance. Still, the child processes are on
another instance - they don't seem to inherit the service from the
parent process.
How can I force all of the child query processes to be on the same
instance as the parent process?
Cheers,
James
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