RE: kkslce [KKSCHLPIN2] mutex contention on hard parse of PQ with binds
Date: Tue, 15 Sep 2015 11:14:24 +0000
Message-ID: <481ea5b7f2414eb59617e48f2a057e01_at_THNMS015.TheHumanNetwork.local>
Hi,
maybe is it this bug/improvement: Bug 17805316 : IMPROVE CURSOR SHARING FOR PX SLAVES FOR STATEMENTS WITH CDT. There are some related bugs but they should already been included in 12c
Herald ten Dam
Superconsult
Van: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] namens Stefan Koehler [contact_at_soocs.de] Verzonden: dinsdag 15 september 2015 12:49 Aan: jonathan_at_jlcomp.demon.co.uk; oracle-l-freelists Onderwerp: RE: kkslce [KKSCHLPIN2] mutex contention on hard parse of PQ with binds
Hi Jonathan,
i guess you are talking about what Mauro and me have talked about here:
- https://www.freelists.org/post/oracle-l/In-what-circumstances-might-optimizer-not-choose-the-lowest-cost,15
- https://www.freelists.org/post/oracle-l/In-what-circumstances-might-optimizer-not-choose-the-lowest-cost,18
Basically it is OCI and fix 9630092 is also disabled by default with 12c (or at least with 12.1.0.1 as i have no 12.1.0.2 at hand right now).
Best Regards
Stefan Koehler
Freelance Oracle performance consultant and researcher
Homepage: http://www.soocs.de
Twitter: _at_OracleSK
> Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> hat am 15. September 2015 um 12:25 geschrieben:
>
> What's the environment from which you are calling the SQL ? Is it a basic SQL*Plus session, or some type of front-end that might be causing the
> double parse with binds anyway ? I forget which mid-tier, or driver it was but there used to be common questions about seeing statement with bind
> variables being parsed twice, once with no values for the bind variable, then a second time because the values were only sent on a second call.
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