Re: slow server

Probably more to do with the kernel that compiled Postgres and the
flags used. -O versus -O2, etc.

Just for kicks, can you try with 7.1?

BTW, did you vacuum both databases shortly before running the queries,
and what happens in a repeated running (say table was in cache for one
system and not on the other).

I also notice a rather significant different in operating system as a
whole.

--
Rod Taylor

There are always four sides to every story: your side, their side, the
truth, and what really happened.
----- Original Message -----
From: "Marc Wrubleski" <mlwruble(at)sorexsoftware(dot)com>
To: <pgsql-general(at)postgresql(dot)org>
Sent: Tuesday, April 03, 2001 3:10 PM
Subject: Re: [GENERAL] slow server

> More info on this problem ...
>
> The Query: select acc.expiringCredits, acc.earnedCredits,
> acc.purchasedCredits,
> acc.statusid, acc.expired from accounts acc, gateways g where
> g.gwnumber = '02000000' and g.accountid = acc.accountid ;
> _________________
> - PIII system. (returns results in .75 seconds per query)
> PostgreSQL 7.0.3 on i686-pc-linux-gnu, compiled by gcc egcs-2.91.66
>
> running on RedHat 6.2 (with Kernel 2.2.16)
>
> Merge Join (cost=8.30..80.93 rows=100 width=25)
> -> Index Scan using accounts_accountid_key on accounts acc
> (cost=0.00..60.00 rows=1000 width=21)
> -> Sort (cost=8.30..8.30 rows=10 width=4)
> -> Index Scan using gateways_gwnumber_key on gateways g
> (cost=0.00..8.14 rows=10 width=4)
> ________________
> Celeron system (returns results in .002 seconds per query)
> PostgreSQL 7.0.2 on i686-pc-linux-gnu, compiled by gcc 2.96
>
> running on RedHat 7.0
>
> Merge Join (cost=8.30..80.93 rows=100 width=25)
> -> Index Scan using accounts_accountid_key on accounts acc
> (cost=0.00..60.00 rows=1000 width=21)
> -> Sort (cost=8.30..8.30 rows=10 width=4)
> -> Index Scan using gateways_gwnumber_key on gateways g
> (cost=0.00..8.14 rows=10 width=4)
>
> I hope this can shed light somewhere. I'm need a starting point
where I
> should start looking. I don't understand why Postgres 7.03 would be
so much
> slower than 7.02.
>
> Marc
>
> Tom Lane wrote:
>
> > Marc Wrubleski <mlwruble(at)sorexsoftware(dot)com> writes:
> > > 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.
> >
> > > Any Ideas?
> >
> > You've managed to tell us absolutely *nothing* of value here.
What
> > Postgres version, what queries, what query plans exactly?
> >
> > > 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?
> >
> > Kinda makes me wonder if they are different PG versions and/or
different
> > configuration options ...
> >
> > regards, tom lane
> >
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