X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 1D3699FA3A3 for ; Mon, 18 Sep 2006 23:50:31 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 20830-03 for ; Tue, 19 Sep 2006 02:50:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id D879D9FA375 for ; Mon, 18 Sep 2006 23:50:20 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id k8J2oJ2W026901; Mon, 18 Sep 2006 22:50:19 -0400 (EDT) To: Marc McIntyre cc: pgsql-performance@postgresql.org Subject: Re: LIKE query problem In-reply-to: <450F303A.6090603@squiz.net> References: <450F303A.6090603@squiz.net> Comments: In-reply-to Marc McIntyre message dated "Tue, 19 Sep 2006 09:48:10 +1000" Date: Mon, 18 Sep 2006 22:50:19 -0400 Message-ID: <26900.1158634219@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200609/242 X-Sequence-Number: 20928 Marc McIntyre writes: > ... Is there a way to perform this efficiently in one query ? No, because you're hoping for an indexscan optimization of a LIKE query, and that can only happen if the pattern is a plan-time constant. regards, tom lane