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To: Li Jin <ljin@tripadvisor.com>
cc: pgsql-performance@postgresql.org
Subject: Re: Performance penalty when using WITH 
In-reply-to: <339959BC-3A27-4269-8A3E-4C157EBABB86@tripadvisor.com> 
References: <339959BC-3A27-4269-8A3E-4C157EBABB86@tripadvisor.com>
Comments: In-reply-to Li Jin <ljin@tripadvisor.com>
	message dated "Thu, 28 Jul 2011 17:00:06 -0400"
Date: Fri, 29 Jul 2011 13:40:27 -0400
Message-ID: <28960.1311961227@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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Li Jin <ljin@tripadvisor.com> writes:
> Anyone knows why the planner is doing this?

WITH is an optimization fence.  This is intentional and documented.

			regards, tom lane