From: Greg Stark <gsstark@mit.edu>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Stark <gsstark@mit.edu>
Cc: Dirk Lutzebaeck <lutzeb@aeccom.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: query produces 1 GB temp file
Date: 05 Feb 2005 17:50:13 -0500
Message-ID: <87mzuik4ey.fsf@stark.xeocode.com> (raw)
In-Reply-To: <29929.1107643284@sss.pgh.pa.us>
References: <20050205182117.0125074@mail2.aeccom.com>
<87y8e2kb8j.fsf@stark.xeocode.com>
<29929.1107643284@sss.pgh.pa.us>
Tom Lane <tgl@sss.pgh.pa.us> writes:
> It was 700k rows to sort, not 22k.
Oops, missed that.
> > The temporary table does need to store three copies of the records at
> > a given time, but still it sounds like an awful lot.
>
> Huh?
Am I wrong? I thought the disk sort algorithm was the polyphase tape sort from
Knuth which is always reading two tapes and writing to a third.
--
greg
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To: pgsql-performance@postgresql.org
Cc: gsstark@mit.edu, tgl@sss.pgh.pa.us, lutzeb@aeccom.com
Subject: Re: query produces 1 GB temp file
In-Reply-To: <87mzuik4ey.fsf@stark.xeocode.com>
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