Re: performance question
- From: Ron Crisco <ron.crisco@xxxxxxxxxxxx>
- To: joan.hsieh@xxxxxxxxx
- Date: Tue, 13 Apr 2010 10:36:20 -0500
Rather than guessing, you can know the answer. Just run 10053 tracing in
both instances and compare. To interpret the results, I highly recommend a
paper written by Wolfgang Breitling, available at
http://www.centrexcc.com/A%20Look%20under%20the%20Hood%20of%20CBO%20-%20the%2010053%20Event.pdf
Ron Crisco
On Tue, Apr 13, 2010 at 9:54 AM, Joan Hsieh <joan.hsieh@xxxxxxxxx> wrote:
> Hi dear listers,
>
> I have a very strange performance issue which I couldn't figure it out.
> I have 2 11.2.0.1 databases with the exactly same parameters, they both on
> the same server. One sql statement run on both database generated 2 diff
> plans. So I exported the whole schema stats from the good db, imported it to
> the bad one. It didn't change the result. I can easily fix the performance
> issue on the bad db by setting optimizer_feature_enabled to 10g, but I just
> wondering why the 2 databases have different plans even after I imported the
> stats and checked the stats.
>
> Thanks,
>
> Joan
>
>
>
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
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