Re: different explain plan on production & test DB

Joe wrote:

> Hi,
>
> Our production database has been copied to our test database a while
> ago, so the contents should be rather similar regarding to number of
> rows etc.
>
> For a heavy SQL I get a completely different explain plan on test than
> on production. What are possible reasons??
>
> - indexes seem to be identicatal
> - statistics are up to date
> ...
>
>
> thanks in advance,
> Joe

Oracle versions and patch levels the same?

Are statistics being obtained in both cases with DBMS_STATS or is one using ANALYZE?

Differences in machine hardware such as CPUs

Differences in initialization parameters

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Daniel Morgan
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