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To: Andreas Joseph Krogh <andreak@officenet.no>
cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: Returning the total number of rows as a separate column when
	using limit
In-reply-to: <200711050836.38130.andreak@officenet.no> 
References: <200711050836.38130.andreak@officenet.no>
Comments: In-reply-to Andreas Joseph Krogh <andreak@officenet.no>
	message dated "Mon, 05 Nov 2007 08:36:38 +0100"
Date: Mon, 05 Nov 2007 09:18:22 -0500
Message-ID: <18728.1194272302@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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Andreas Joseph Krogh <andreak@officenet.no> writes:
> AFAICS the information about the *total* number of rows is in the "result" 
> somehow. When I execute a "limit 1" query with EXPLAIN ANALYZE, I se the 
> total number of columns in "rows=200819", so the information is there.

That's only an estimate.  Since the query doesn't get executed to
completion thanks to the LIMIT, Postgres really has no idea whether
the estimate is accurate.

			regards, tom lane