From: Tom Lane <tgl@sss.pgh.pa.us>
To: wmiro@ig.com.br <wmiro@ig.com.br>
Cc: pgsql-performance@postgresql.org
Subject: Re: Why the 8.1 plan is worst than 7.4?
Date: Tue, 30 May 2006 23:20:46 -0400
Message-ID: <6069.1149045646@sss.pgh.pa.us> (raw)
In-Reply-To: <20060526_120456_040065.wmiro@ig.com.br>
References: <20060526_120456_040065.wmiro@ig.com.br>
"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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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, wmiro@ig.com.br
Subject: Re: Why the 8.1 plan is worst than 7.4?
In-Reply-To: <6069.1149045646@sss.pgh.pa.us>
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