From: Tom Lane <tgl@sss.pgh.pa.us>
To: Frank Joerdens <frank@joerdens.de>
Cc: pgsql-performance@postgresql.org, Nic <nferrier@tapsellferrier.co.uk>
Cc: Seb Potter <seb@woome.com>
Subject: Re: Query w empty result set with LIMIT orders of magnitude slower than without
Date: Tue, 26 Aug 2008 12:53:09 -0400
Message-ID: <10025.1219769589@sss.pgh.pa.us> (raw)
In-Reply-To: <7d10d2df0808260937v3103e216h764bbb74ca597d6f@mail.gmail.com>
References: <7d10d2df0808260937v3103e216h764bbb74ca597d6f@mail.gmail.com>
"Frank Joerdens" <frank@joerdens.de> writes:
> It seems to me that the planner makes a very poor decision with this
> particular query:
Try increasing the stats on woouser. You need it to make a smaller
estimate of the number of matching rows here:
> -> Index Scan Backward using webapp_invite_pkey on
> webapp_invite (cost=0.00..201698.51 rows=382 width=44) (actual
> time=2545.131..2545.131 rows=0 loops=1)
> Filter: ((woouser)::text = 'suggus'::text)
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, frank@joerdens.de, nferrier@tapsellferrier.co.uk, seb@woome.com
Subject: Re: Query w empty result set with LIMIT orders of magnitude slower than without
In-Reply-To: <10025.1219769589@sss.pgh.pa.us>
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