X-Original-To: pgsql-performance@postgresql.org Received: from spampd.localdomain (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 7BBB0475AE5 for ; Fri, 9 May 2003 09:06:38 -0400 (EDT) Received: from matrix.gatewaynet.com (unknown [217.19.69.50]) by postgresql.org (Postfix) with ESMTP id 0E72C475A80 for ; Fri, 9 May 2003 09:06:35 -0400 (EDT) Received: from matrix.gatewaynet.com (localhost [127.0.0.1]) by matrix.gatewaynet.com (8.12.5/8.12.5) with ESMTP id h49IBn1s007457; Fri, 9 May 2003 16:11:49 -0200 Received: from localhost (achill@localhost) by matrix.gatewaynet.com (8.12.5/8.12.5/Submit) with ESMTP id h49IBngw007453; Fri, 9 May 2003 16:11:49 -0200 Date: Fri, 9 May 2003 16:11:49 -0200 (GMT+2) From: Achilleus Mantzios To: Tom Lane Cc: pgsql-performance@postgresql.org Subject: Re: An unresolved performance problem. In-Reply-To: <29797.1052483506@sss.pgh.pa.us> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Status: No, hits=-38.4 required=5.0 tests=BAYES_00,EMAIL_ATTRIBUTION,IN_REP_TO,QUOTED_EMAIL_TEXT, QUOTE_TWICE_1,REPLY_WITH_QUOTES,SIGNATURE_LONG_DENSE, USER_AGENT_PINE autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) X-Archive-Number: 200305/112 X-Sequence-Number: 1891 On Fri, 9 May 2003, Tom Lane wrote: > Achilleus Mantzios writes: > > If so, how can one find the correlation between the ordering > > of a table and a multicolumn index? > > Well, it is surely no better than the correlation of the index's > first column --- what is that? it is 1 > > regards, tom lane > -- ================================================================== Achilleus Mantzios S/W Engineer IT dept Dynacom Tankers Mngmt Nikis 4, Glyfada Athens 16610 Greece tel: +30-210-8981112 fax: +30-210-8981877 email: achill@matrix.gatewaynet.com mantzios@softlab.ece.ntua.gr