Re: slow query
От | Tom Lane |
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Тема | Re: slow query |
Дата | |
Msg-id | 19157.1175750845@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | Re: slow query ("A. Kretschmer" <andreas.kretschmer@schollglas.com>) |
Ответы |
Re: slow query
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Список | pgsql-sql |
"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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