From: Tom Lane <tgl@sss.pgh.pa.us>
To: A. Kretschmer <andreas.kretschmer@schollglas.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: slow query
Date: Thu, 05 Apr 2007 01:27:25 -0400
Message-ID: <19157.1175750845@sss.pgh.pa.us> (raw)
In-Reply-To: <20070405051127.GA24814@a-kretschmer.de>
References: <7539aebb0704042017l70d83d53u9c2e5105620a3fa7@mail.gmail.com>
<20070405051127.GA24814@a-kretschmer.de>
"A. Kretschmer" <andreas.kretschmer@schollglas.com> writes:
> am Wed, dem 04.04.2007, um 23:17:54 -0400 mailte Sumeet folgendes:
>> sm=> explain analyze select * from ma limit 10;
>> QUERY
>> PLAN
>> -------------------------------------------------------------------------------------------------------------------------------------
>> Limit (cost=0.00..0.45 rows=10 width=76) (actual time=21985.292..22204.340
>> rows=10 loops=1)
>> -> Seq Scan on ma (cost=0.00..2181956.92 rows=48235392 width=76) (actual
>> time=21985.285..22204.308 rows=10 loops=1)
>> Total runtime: 22204.476 ms
>> (3 rows)
> which version?
I'm betting the problem is poor vacuuming practice leading to lots of
dead space. There's no way it takes 22 sec to read 10 rows if the
table is reasonably dense.
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, andreas.kretschmer@schollglas.com
Subject: Re: slow query
In-Reply-To: <19157.1175750845@sss.pgh.pa.us>
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