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Re: Why the 8.1 plan is worst than 7.4? - Mailing list pgsql-performance

From Tom Lane
Subject Re: Why the 8.1 plan is worst than 7.4?
Date
Msg-id 6069.1149045646@sss.pgh.pa.us
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In response to Why the 8.1 plan is worst than 7.4?  (wmiro@ig.com.br <wmiro@ig.com.br>)
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"wmiro@ig.com.br" <wmiro@ig.com.br> writes:
> Why the plan is worst in postgres 8.1?

(1) you have not actually shown us that the plan is worse.  If you are
complaining that the planner is wrong, EXPLAIN output (which contains
only the planner's estimates) is useless for proving your point.  Show
EXPLAIN ANALYZE.

(2) Have you ANALYZEd these tables recently in either database?  The
discrepancies in estimated rowcounts suggest that the two planners
are working with different statistics.

            regards, tom lane

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