Re: somewhat slow query with subselect - Mailing list pgsql-general

From Tom Lane
Subject Re: somewhat slow query with subselect
Date
Msg-id 22991.1251219125@sss.pgh.pa.us
Whole thread Raw
In response to somewhat slow query with subselect  (Marcus Engene <mengpg2@engene.se>)
Responses Re: somewhat slow query with subselect
List pgsql-general
Marcus Engene <mengpg2@engene.se> writes:
> ... In a case with some 5000 rows belonging to owner 123, this select really
> takes a long time. Way longer than without the subselect and order by
> filelength. I agree that with the subselect it would take some extra
> juice, but in my mind it would do some hash in memory which wouldn't be
> too slow to lookup in.

8.4 can turn EXISTS subqueries into hash joins, but previous releases
won't...

            regards, tom lane

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