From: Luke Lonergan <llonergan@greenplum.com>
To: Laszlo Nagy <gandalf@designaproduct.biz>
To: pgsql-performance@postgresql.org
Subject: Re: Poor performance on seq scan
Date: Tue, 12 Sep 2006 15:18:11 -0700
Message-ID: <C12C8033.30BC3%llonergan@greenplum.com> (raw)
In-Reply-To: <45072B61.3080506@designaproduct.biz>
Lazlo,
On 9/12/06 2:49 PM, "Laszlo Nagy" <gandalf@designaproduct.biz> wrote:
> I'm using FreeBSD, and not just because it dynamically alters the
> priority of long running processes. :-)
Understood.
Linux and FreeBSD often share some driver technology.
I have had extremely bad performance historically with onboard SATA chipsets
on Linux. The one exception has been with the Intel based chipsets (not the
CPU, the I/O chipset).
It is very likely that you are having problems with the driver for the
chipset.
Are you running RAID1 in hardware? If so, turn it off and see what the
performance is. The onboard hardware RAID is worse than useless, it
actually slows the I/O down.
If you want RAID with onboard chipsets, use software RAID, or buy an adapter
from 3Ware or Areca for $200.
- Luke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: llonergan@greenplum.com, gandalf@designaproduct.biz
Subject: Re: Poor performance on seq scan
In-Reply-To: <C12C8033.30BC3%llonergan@greenplum.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox