From: Alan Stange <stange@rentec.com>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: Dave Cramer <pg@fastcrypt.com>
Cc: Greg Stark <gsstark@mit.edu>
Cc: Joshua Marsh <icub3d@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Hardware/OS recommendations for large databases (
Date: Fri, 18 Nov 2005 11:13:44 -0500
Message-ID: <437DFDB8.1030208@rentec.com> (raw)
In-Reply-To: <BFA332EE.14035%llonergan@greenplum.com>
References: <BFA332EE.14035%llonergan@greenplum.com>
Luke Lonergan wrote:
> Alan,
>
> On 11/18/05 6:46 AM, "Alan Stange" <stange@rentec.com> wrote:
>
> That's 3 hours under load, with 80 compute clients beating on the
> database at the same time. We have the stats turned way up, so the
> analyze tends to read a big chunk of the tables a second time as
> well. We typically don't have three hours a day of idle time.
>
>
> So I guess you’re saying you don’t know what your I/O rate is?
No, I'm say *you* don't know what my IO rate is.
I told you in my initial post that I was observing numbers in excess of
what you claiming, but you seemed to think I didn't know how to measure
an IO rate.
I should note too that our system uses about 20% of a single cpu when
performing a table scan at >100MB/s of IO. I think you claimed the
system would be cpu bound at this low IO rate.
Cheers,
-- Alan
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To: pgsql-performance@postgresql.org
Cc: stange@rentec.com, llonergan@greenplum.com, pg@fastcrypt.com, gsstark@mit.edu, icub3d@gmail.com
Subject: Re: Hardware/OS recommendations for large databases (
In-Reply-To: <437DFDB8.1030208@rentec.com>
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