Re: slow server - Mailing list pgsql-general

In addition to my previous questions and all other questions, I have another
:-)

Where are you getting your .002 and .75 numbers? Perhaps it's the way in
which you're measuring the queries that has the problem? Oh and what OS are
you using?

-Mitch
Software development :
You can have it cheap, fast or working. Choose two.

----- Original Message -----
From: "Richard Huxton" <dev@archonet.com>
To: "Marc Wrubleski" <mlwruble@sorexsoftware.com>;
<pgsql-general@postgresql.org>
Sent: Tuesday, April 03, 2001 4:41 PM
Subject: Re: slow server


> From: "Marc Wrubleski" <mlwruble@sorexsoftware.com>
>
> > Hi, I have two systems one is a 500Mhz Celeron with 128 MB ram and IDE
> > Disks, the other is 800Mhz PIII, 512MB RAM, SCSI Disks.
> >
> > Obviously the PIII should stomp on the performance of the Celeron, but
> > my postgres installation on the faster system is MUCH slower.
> >
> > I simple query on two tables joined on the celeron takes about .002
> > seconds. On the PIII it takes .75 seconds. Same Query, same tables, same
> > indexes. The results from explain are the same. the results from the
> > query are the same.
>
> 0.002 seconds? Doubtful, but even if it was 0.2 seconds the results are
> puzzling. There's someone else with a suspiciously similar question
recently
> too (Daniel Akerud - but with a circle over the A)
>
> > Any Ideas?
> >
> > One thing to think about is the PIII was installed via RPM and the
> > Celeron wass compiled on that machine. Could this be the limiting
> > factor?
>
> Well - RPMs tend to be i386 optimised rather than for Pentiums (ie they're
> not), but that'd be all. I take it you're not seeing any disk activity
> during this query, which would mean it *must* be CPU related.
>
> Could you post the version of Postgres you have on each machine, along
with
> the explain for the query? It might mean something to one of the
developers.
> Oh - OS with versions would be useful too (Linux presumably, but versions
> might be useful).
>
> FWIW there are only two things I can think of:
>
> 1. Cache issues - maybe the RPM is breaking the caching on the PIII
> 2. Broken socket code - although I can't think what would do this
> 3. The RPM and compiled versions are different and something odd has
> changed.
>
> If nothing else on the machine seems slow, I can only suggest compiling
from
> source and seeing what that does for you.
>
> - Richard Huxton
>
>
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