Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 2BD736328CA for ; Mon, 2 Aug 2010 14:29:55 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 49155-01 for ; Mon, 2 Aug 2010 17:29:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id 2027A632437 for ; Mon, 2 Aug 2010 14:29:48 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id o72HTlpO020343; Mon, 2 Aug 2010 13:29:47 -0400 (EDT) To: Mark Rostron cc: "pgsql-performance@postgresql.org" Subject: Re: what does "initplan" operation in explain output mean? In-reply-to: References: <4572.1280671706@sss.pgh.pa.us> Comments: In-reply-to Mark Rostron message dated "Mon, 02 Aug 2010 09:42:45 -0700" Date: Mon, 02 Aug 2010 13:29:47 -0400 Message-ID: <20342.1280770187@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201008/6 X-Sequence-Number: 39849 Mark Rostron writes: > So am I right in assuming that the aggregate sub-query ( against work_active ) results will not assist with constraint exclusion in the sub-query against work_unit (if we introduce range partitions on this table)? Dunno. You didn't actually show what you were hoping would work, or work differently as the case may be. regards, tom lane