From: Andres Freund <andres@anarazel.de>
To: Maciek Sakrejda <msakrejda@truviso.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Optimizing NOT IN plans / verify rewrite
Date: Mon, 2 Aug 2010 21:52:57 +0200
Message-ID: <20100802195257.GA2892@anarazel.de> (raw)
In-Reply-To: <AANLkTim0entqazUpWhwotC+gcDGrmeM=a=WPJUv=MgdO@mail.gmail.com>
References: <AANLkTim0entqazUpWhwotC+gcDGrmeM=a=WPJUv=MgdO@mail.gmail.com>
Hi,
On Mon, Aug 02, 2010 at 12:12:51PM -0700, Maciek Sakrejda wrote:
> I'm running PostgreSQL 8.3 and I have a query with a couple of NOT IN
> subqueries:
With 8.3 you will have to use manual antijoins (i.e LEFT JOIN
... WHERE NULL). If you use 8.4 NOT EXISTS() will do that
automatically in many cases (contrary to NOT IN () which has strange
NULL semantics).
Anbdres
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To: pgsql-performance@postgresql.org
Cc: andres@anarazel.de, msakrejda@truviso.com
Subject: Re: Optimizing NOT IN plans / verify rewrite
In-Reply-To: <20100802195257.GA2892@anarazel.de>
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