Re: Superfluous merge/sort

From: Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com>
To: Anuradha Ratnaweera <ARatnaweera(at)virtusa(dot)com>
Cc: <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Superfluous merge/sort
Date: 2003-02-25 15:56:14
Message-ID: 20030225075139.V57635-100000@megazone23.bigpanda.com
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On Tue, 25 Feb 2003, Anuradha Ratnaweera wrote:

> Question in brief: does the planner/optimizer take into account the
> foreign key constraints?
>
> If the answer is "no", please stop reading here.

Not really. However, as a note, from t1,t2 where t1.id=t2.id is not
necessarily an identity even with the foreign key due to NULLs.

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