X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (neptune.hub.org [200.46.204.2]) by svr1.postgresql.org (Postfix) with ESMTP id B54F8D1B441 for ; Sat, 27 Dec 2003 10:07:34 +0000 (GMT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (neptune.hub.org [200.46.204.2]) (amavisd-new, port 10024) with ESMTP id 16745-10 for ; Sat, 27 Dec 2003 06:06:47 -0400 (AST) Received: from noon.pghoster.com (noon.pghoster.com [64.246.0.64]) by svr1.postgresql.org (Postfix) with ESMTP id 5D355D1B458 for ; Sat, 27 Dec 2003 06:06:44 -0400 (AST) Received: from [61.94.40.147] (helo=winxp) by noon.pghoster.com with asmtp (Exim 4.24) id 1AaBLC-0001h5-6o; Sat, 27 Dec 2003 04:06:39 -0600 Message-ID: <000801c3cc61$1cdc75d0$93285e3d@winxp> From: "Chris Travers" To: "Yasir Malik" , "PostgreSQL" References: <3FECB238.1050801@sancharnet.in> <200312261934.35070.martin@bugs.unl.edu.ar> Subject: Re: Anti log in PostgreSQL Date: Sat, 27 Dec 2003 09:14:40 +0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - noon.pghoster.com X-AntiAbuse: Original Domain - postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - travelamericas.com X-Virus-Scanned: by amavisd-new at postgresql.org X-Archive-Number: 200312/199 X-Sequence-Number: 16365 Definition of log (base n) is that log n(x) = y where n^y = x for all values of x and y. n is the base. So a base 10 log would be reversed by doing 10^x=y. If we know x, we use the exponential operation; if we know y we use log(y) = x. For ln (natural logs, base e, e is approx. 2.818), use e^x=y. Hope this explains things. Best Wishes, Chris Travers