Can we have pending system statistics in 11g /RC for plan switch between NL & HJ
From: kunwar singh <krishsingh.111_at_gmail.com>
Date: Wed, 26 Sep 2018 04:54:31 -0400
Message-ID: <CAJSrDUrsshnz5Jw6fEbQgLpF+aFcFBwsM4qWn8vGNeZw2NSj6g_at_mail.gmail.com>
Hi everyone,
I am having a hard time in debugging the RC for many plan differences between 2 DBs where the only difference is in system statistics (especially MREADTIM and CPUSPEED) . All other DB parameters are same.
Kunwar
Date: Wed, 26 Sep 2018 04:54:31 -0400
Message-ID: <CAJSrDUrsshnz5Jw6fEbQgLpF+aFcFBwsM4qWn8vGNeZw2NSj6g_at_mail.gmail.com>
Hi everyone,
I am having a hard time in debugging the RC for many plan differences between 2 DBs where the only difference is in system statistics (especially MREADTIM and CPUSPEED) . All other DB parameters are same.
Bad plans (using NL joins) in PROD. Good plan( Hash joins) in test
I read this article from Franck and one more where he mention an existing
bug opened.
https://blog.dbi-services.com/can-you-have-pending-system-statistics/
Is there any workaround to getting *pending system statistics *working in 11.2.0.4 in order to check if that will resolve the problem? I do not want to cause widespread issues by importing system statistics when i know ( per the above blog) that system statistics wont remain pending!
Or would you suggest any other structured approach in order to find the
problem? I am not good at all in reading 10053 trace .
--
Kunwar
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Received on Wed Sep 26 2018 - 10:54:31 CEST