From: Stephan Szabo <sszabo@megazone.bigpanda.com>
To: Dario <dario_d_s@unitech.com.ar>
Cc: pgsql-performance@postgresql.org
Subject: Re: join and query planner
Date: Wed, 6 Jul 2005 15:34:03 -0700 (PDT)
Message-ID: <20050706152750.V50953@megazone.bigpanda.com> (raw)
In-Reply-To: <MHEDJHCKDNOEHJKHIOCJIEFLCEAA.dario_d_s@unitech.com.ar>
References: <MHEDJHCKDNOEHJKHIOCJIEFLCEAA.dario_d_s@unitech.com.ar>
On Wed, 6 Jul 2005, Dario wrote:
>
> (first at all, sorry for my english)
> Hi.
> - Does "left join" restrict the order in which the planner must join
> tables? I've read about join, but i'm not sure about left join...
Yes. Reordering the outer joins can change the results in some cases which
would be invalid. Before we can change the ordering behavior, we really
need to know under what conditions it is safe to do the reordering.
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To: pgsql-performance@postgresql.org
Cc: sszabo@megazone.bigpanda.com, dario_d_s@unitech.com.ar
Subject: Re: join and query planner
In-Reply-To: <20050706152750.V50953@megazone.bigpanda.com>
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