Re: High CPU Load

Hi Scott,

Le jeudi 14 septembre 2006 à 10:56 -0500, Scott Marlowe a écrit :
> On Thu, 2006-09-14 at 10:02, Dave Dutcher wrote:
> > > -----Original Message-----
> > > From: pgsql-performance-owner@postgresql.org
> > > [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of
> > > Jérôme BENOIS
> > >
> >  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 (((
> > > select distinct ei_id as EIID from mpng2_ei_attribute as
> > > reqin1 where reqin1.CATEGORYATTR_ID = 0 AND reqin1.TEXT_VALUE
> > > ilike '' and ei_id in ( select distinct ei_id as EIID from
> > > mpng2_ei_attribute as reqin2 where reqin2.CATEGORYATTR_ID = 0
> > > AND reqin2.TEXT_VALUE ilike '' and ei_id in ( select distinct
> > > ei_id as EIID from mpng2_ei_attribute as reqin3 where
> > > reqin3.NAME = '' AND reqin3.STRING_VALUE = '' ) ) ) ) ) as
> > > req0 join mpng2_ei_attribute on req0.eiid =
> > > mpng2_ei_attribute.ei_id order by ei_id asc;
> >
> >
> > 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 usage
> > is high.
>
> 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 Jérôme confirm or deny this?
>

The locale used to run initdb is :

su - postgres
:~$ locale
LANG=POSIX
LC_CTYPE="POSIX"
LC_NUMERIC="POSIX"
LC_TIME="POSIX"
LC_COLLATE="POSIX"
LC_MONETARY="POSIX"
LC_MESSAGES="POSIX"
LC_PAPER="POSIX"
LC_NAME="POSIX"
LC_ADDRESS="POSIX"
LC_TELEPHONE="POSIX"
LC_MEASUREMENT="POSIX"
LC_IDENTIFICATION="POSIX"
LC_ALL=

Cheers,
--
Jérôme,

python -c "print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in 'sioneb@gnireenigne-aigra.rf'.split('@')])"