RE: Bind Variable Peeking issue
- From: "Allen, Brandon" <Brandon.Allen@xxxxxxxxxxx>
- To: "Santhosh.Channa@xxxxxxxxxxxx" <Santhosh.Channa@xxxxxxxxxxxx>, "krishna000@xxxxxxxxx" <krishna000@xxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 17 Sep 2009 09:35:17 -0700
Bala, beware that disabling bind variable peeking at the system level could
have a major impact on all other queries using bind variables on the system so
it should be done with caution after thoroughly testing on a test database
first.
You don't have to analyze the table to invalidate it's dependent cursors - you
can just issue a grant on it (e.g. grant select on mytable to system). This is
much faster and avoids the performance impact and other potential side effects
of updating statistics.
In order to answer why this type of invalidation didn't resolve the problem you
need to dig deeper to see exactly what's happening - keep an eye on the
child_number and plan_hash_value columns of v$sql and also v$sql_bind_capture
to see exactly what bind variables are being evaluated at hard parse time and
what plans are being chosen for those variables.
Regards,
Brandon
________________________________
Privileged/Confidential Information may be contained in this message or
attachments hereto. Please advise immediately if you or your employer do not
consent to Internet email for messages of this kind. Opinions, conclusions and
other information in this message that do not relate to the official business
of this company shall be understood as neither given nor endorsed by it.
Other related posts:
