Re: BUG #1851: Performance reduction from 8.0.3 - Mailing list pgsql-bugs

From Tom Lane
Subject Re: BUG #1851: Performance reduction from 8.0.3
Date
Msg-id 26654.1125098220@sss.pgh.pa.us
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In response to BUG #1851: Performance reduction from 8.0.3  ("Steve Wormley" <steve@wormley.com>)
Responses Re: BUG #1851: Performance reduction from 8.0.3  (Steve Wormley <steve@wormley.com>)
List pgsql-bugs
"Steve Wormley" <steve@wormley.com> writes:
> Did a dump and restore of my DB to 8.1beta1 (running concurrently with
> 8.0.3) and performance on the same query is about 50% slower with the beta.
> Ran query twice on each instance in sequence to make sure all data was in OS
> cache.

Did you vacuum analyze (or at least analyze) both databases?  The
rowcount estimates seem quite a bit different, which suggests the
two planners aren't working with the same stats.

            regards, tom lane

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