From: | "Shridhar Daithankar" <shridhar_daithankar(at)persistent(dot)co(dot)in> |
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To: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Simple queries take forever to run |
Date: | 2003-08-28 14:45:40 |
Message-ID: | 3F4E62EC.15091.71172C@localhost |
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Lists: | pgsql-performance |
On 28 Aug 2003 at 10:38, Michael Guerin wrote:
> >IN(subquery) is known to run poorly in 7.3.x and earlier. 7.4 is
> >generally much better (for reasonably sized subqueries) but in earlier
> >versions you'll probably want to convert into an EXISTS or join form.
> Something else seems to be going on, even switching to an exists clause
> gives much better but poor performance.
> count(*) where exists clause: Postgresql 19s, SQL Server <1s
> count(*) where not exists: 23.3s SQL Server 1.5s
This was with 7.4? Can you try downloading 7.4CVS and try?
>
> SQL Server runs on a dual 1.4 with 4gigs, win2k
> Postgresql runs on a quad 900 with 8 gigs, sunos 5.8
SunOS...Not the impala out there but anyways I would refrain from slipping in
that..
Parden me if this is a repeatation, have you set your effective cache size?
Bye
Shridhar
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