From: Mark Kirkwood <markir@paradise.net.nz>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: stange@rentec.com, Greg Stark <gsstark@mit.edu>
Cc: Dave Cramer <pg@fastcrypt.com>
Cc: Joshua Marsh <icub3d@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Hardware/OS recommendations for large databases (
Date: Thu, 24 Nov 2005 22:24:35 +1300
Message-ID: <438586D3.9010701@paradise.net.nz> (raw)
In-Reply-To: <BFAAB702.1460D%llonergan@greenplum.com>
References: <BFAAB702.1460D%llonergan@greenplum.com>
Luke Lonergan wrote:
> That says it's something else in the path. As you probably know there is a
> page lock taken, a copy of the tuple from the page, lock removed, count
> incremented for every iteration of the agg node on a count(*). Is the same
> true of a count(1)?
>
Sorry Luke - message 3 - I seem to be suffering from a very small
working memory buffer myself right now, I think it's after a day of
working with DB2 ... :-)
Anyway, as I read src/backend/parser/gram.y:6542 - count(*) is
transformed into count(1), so these two are identical.
Cheers (last time tonight, promise!)
Mark
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Cc: markir@paradise.net.nz, llonergan@greenplum.com, gsstark@mit.edu, pg@fastcrypt.com, icub3d@gmail.com
Subject: Re: Hardware/OS recommendations for large databases (
In-Reply-To: <438586D3.9010701@paradise.net.nz>
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