Re: Predicate migration on complex self joins

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
Cc: "Simon Riggs" <simon(at)2ndQuadrant(dot)com>, "pgsql-hackers" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Predicate migration on complex self joins
Date: 2009-07-13 17:49:22
Message-ID: 26647.1247507362@sss.pgh.pa.us
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"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
> Simon Riggs <simon(at)2ndQuadrant(dot)com> wrote:
>> select count(*)
>> from foo1 a, foo1 b
>> where a.c1 = b.c1 /* PK join */

> We had to do something like that to get acceptable performance from
> Sybase ASE.

Writing a join for a single-table query? Why, in heavens name?
(Or have you mercifully blotted the details from your memory?)

regards, tom lane

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