From: Luke Lonergan <llonergan@greenplum.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
To: pgsql-performance@postgresql.org
Subject: Re: Good News re count(*) in 8.1
Date: Wed, 22 Feb 2006 09:11:50 -0800
Message-ID: <C021DB56.1D021%llonergan@greenplum.com> (raw)
In-Reply-To: <43FC4384.EE98.0025.0@wicourts.gov>
Kevin,
On 2/22/06 8:57 AM, "Kevin Grittner" <Kevin.Grittner@wicourts.gov> wrote:
> I hesitate to raise this issue again, but I've noticed something which I
> thought might be worth mentioning. I've never thought the performance
> of count(*) on a table was a significant issue, but I'm prepared to say
> that -- for me, at least -- it is officially and totally a NON-issue.
Cool! Kudos to Tom for implementing the improvements in the executor to
move tuples faster through the pipeline.
We see a CPU limit (yes, another limit) of about 300MB/s now on Opteron 250
processors running on Linux. The filesystem can do 420MB/s sequential scan
in 8k pages, but Postgres count(*) on 8.1.3 can only do about 300MB/s. This
is still a very large improvement over past versions, but we'd always like
to see more...
- Luke
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To: pgsql-performance@postgresql.org
Cc: llonergan@greenplum.com, Kevin.Grittner@wicourts.gov
Subject: Re: Good News re count(*) in 8.1
In-Reply-To: <C021DB56.1D021%llonergan@greenplum.com>
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