Re: PQ_DISTRIBUTE Usage in NON Parallel Queries

Did the OL$HINTS table also have a noparallel and noparallel_index hint ? If not, then the query could go parallel, which would make a pq_distribute hint relevant..

Alternatively, there are a few oddities in the 9.2.0.5 when it comes to parallel query that I have not been able to reproduce in 9.2.0.4 and 9.2.0.6 (yet), so maybe you've found a symptom of a generic parallel bug.

Regards

Jonathan Lewis

http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ

http://www.jlcomp.demon.co.uk/seminar.html Public Appearances - schedule updated Jan 21st 2005

• Original Message ----- From: "Larry Elkins" <elkinsl_at_flash.net> To: <oracle-l_at_freelists.org> Sent: Saturday, February 05, 2005 1:41 AM Subject: PQ_DISTRIBUTE Usage in NON Parallel Queries

Listers,

In what way does the PQ_DISTRIBUTE "hint" apply to non parallel queries? I ran into a need to use a stored outline a while back. And the query does not use parallelism. When capturing the desired plan in the OL$HINTS table for the outline there is a PQ_DISTRIBUTE hint. The docs categorize it as a parallel related hint, and I've had to use it a couple of times in the past related to parallel queries for huge batch jobs (and yes, I tried tweaking stats first ;-)).

This actually came up a couple of months ago, and I no longer have access to the system or else I would dig into it a bit more, and even provide the SQL, it's plan, and the data from OL$HINTS to the list. But no can do without access to it. I just find it odd that the docs, and whatever else Oracle puts out on Metalink, etc, that it is always referred to as being a parallel related hint. Yet it appears in OL$HINTS for a SQL statement not using parallelism.

Oh yeah, 9.2.0.5 EE. And I'm going to see if I can duplicate on 8i and 9i here at home, but thought I would throw the question out to the list as well.

Regards,

Larry G. Elkins
elkinsl_at_flash.net
214.954.1781

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http://www.freelists.org/webpage/oracle-l Received on Sun Feb 06 2005 - 11:53:01 CST