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@xxxxxxxxxxxxx [oracle-l-bounce@xxxxxxxxxxxxx] namens
Stefan Koehler [contact@xxxxxxxx]
Verzonden: dinsdag 15 september 2015 12:49
Aan: jonathan@xxxxxxxxxxxxxxxxxx; 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: @OracleSK
Jonathan Lewis <jonathan@xxxxxxxxxxxxxxxxxx> 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.
