X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id BD227DAF95 for ; Wed, 26 Oct 2005 20:06:19 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 30334-04 for ; Wed, 26 Oct 2005 23:06:16 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id A6860DAF7D for ; Wed, 26 Oct 2005 20:06:17 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j9QN6FIQ012334; Wed, 26 Oct 2005 19:06:15 -0400 (EDT) To: "Steinar H. Gunderson" Cc: pgsql-performance@postgresql.org Subject: Re: Materializing a sequential scan In-reply-to: <20051026213730.GA2295@uio.no> References: <20051019174544.GA32303@samfundet.no> <20051026213730.GA2295@uio.no> Comments: In-reply-to "Steinar H. Gunderson" message dated "Wed, 26 Oct 2005 23:37:30 +0200" Date: Wed, 26 Oct 2005 19:06:15 -0400 Message-ID: <12333.1130367975@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 required=5 tests=[AWL=0.006] X-Spam-Level: X-Archive-Number: 200510/400 X-Sequence-Number: 15168 "Steinar H. Gunderson" writes: > Any good ideas why 8.1 would refuse to do this, when 7.4 would do it? It does > not matter how high I set my work_mem; even at 2.000.000 it refused to hash > the subplan. AFAICS, subplan_is_hashable() is testing the same conditions in 7.4 and HEAD, so this isn't clear. Want to step through it and see where it's deciding not to hash? regards, tom lane