Subject: Re: High CPU Load
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Dave Dutcher <dave@tridecap.com>
Cc: =?ISO-8859-1?Q?=27J=E9r=F4me?= BENOIS' <benois@argia-engineering.fr>,
	pgsql-performance@postgresql.org
In-Reply-To: <004001c6d80e$bdef5bc0$8300a8c0@tridecap.com>
References: <004001c6d80e$bdef5bc0$8300a8c0@tridecap.com>
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Date: Thu, 14 Sep 2006 10:56:52 -0500

On Thu, 2006-09-14 at 10:02, Dave Dutcher wrote:
> > -----Original Message-----
> > From: pgsql-performance-owner@postgresql.org=20
> > [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of=20
> > J=C3=A9r=C3=B4me BENOIS
> >=20
>  explain analyze select distinct
> > INTEGER_VALUE,DATE_VALUE,EI_ID,VALUE_TYPE,FLOAT_VALUE,ID,TEXT_
> > VALUE,CATEGORY_ID,STRING_VALUE,CATEGORYATTR_ID,NAME from (((=20
> > select distinct ei_id as EIID from mpng2_ei_attribute as=20
> > reqin1 where reqin1.CATEGORYATTR_ID =3D 0 AND reqin1.TEXT_VALUE=20
> > ilike '' and ei_id in ( select distinct ei_id as EIID from=20
> > mpng2_ei_attribute as reqin2 where reqin2.CATEGORYATTR_ID =3D 0=20
> > AND reqin2.TEXT_VALUE ilike '' and ei_id in ( select distinct=20
> > ei_id as EIID from mpng2_ei_attribute as reqin3 where=20
> > reqin3.NAME =3D '' AND reqin3.STRING_VALUE =3D '' ) ) ) ) ) as=20
> > req0 join mpng2_ei_attribute on req0.eiid =3D=20
> > mpng2_ei_attribute.ei_id order by ei_id asc;
>=20
>=20
> That is a lot of distinct's.  Sorts are one thing that can really use up
> CPU.  This query is doing lots of sorts, so its not surprising the CPU us=
age
> is high. =20

I'm gonna make a SWAG here and guess that maybe your 7.4 db was initdb'd
with a locale of C and the new one is initdb'd with a real locale, like
en_US.  Can J=C3=A9r=C3=B4me confirm or deny this?