From: Tom Lane <tgl@sss.pgh.pa.us>
To: Rikard Pavelic <rikard.pavelic@zg.htnet.hr>
Cc: pgsql-performance@postgresql.org
Subject: Re: self join revisited
Date: Wed, 01 Apr 2009 13:19:10 -0400
Message-ID: <7884.1238606350@sss.pgh.pa.us> (raw)
In-Reply-To: <49D3969F.4030701@zg.htnet.hr>
References: <49D3969F.4030701@zg.htnet.hr>
Rikard Pavelic <rikard.pavelic@zg.htnet.hr> writes:
> It would be great if Postgres could rewrite this query
AFAICS those queries are not going to produce the same results,
so Postgres would be 100% incorrect to rewrite it like that for you.
(If they do produce the same results, it would depend on a bunch
of assumptions you have not stated.)
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, rikard.pavelic@zg.htnet.hr
Subject: Re: self join revisited
In-Reply-To: <7884.1238606350@sss.pgh.pa.us>
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