Skip site navigation (1) Skip section navigation (2)

Re: Simple queries take forever to run

From: "Shridhar Daithankar" <shridhar_daithankar(at)persistent(dot)co(dot)in>
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 (view raw, whole thread or download thread mbox)
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 

Parden me if this is a repeatation,  have you set your effective cache size?


Nouvelle cuisine, n.:	French for "not enough food".Continental breakfast, n.:	
English for "not enough food".Tapas, n.:	Spanish for "not enough food".Dim Sum, 
n.:	Chinese for more food than you've ever seen in your entire life.

In response to

pgsql-performance by date

Next:From: Stephan SzaboDate: 2003-08-28 15:19:53
Subject: Re: Simple queries take forever to run
Previous:From: Rod TaylorDate: 2003-08-28 14:41:52
Subject: Re: Hardware recommendations to scale to silly load

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group