X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 48D719FB250 for ; Wed, 3 May 2006 03:49:02 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 97130-02 for ; Wed, 3 May 2006 03:48:24 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.199]) by postgresql.org (Postfix) with ESMTP id 7C5889FB2C0 for ; Wed, 3 May 2006 03:21:27 -0300 (ADT) Received: by nz-out-0102.google.com with SMTP id x7so95098nzc for ; Tue, 02 May 2006 23:21:26 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:user-agent:x-accept-language:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=uK57w2W4JzPsGckM+OXdsVpn6tRf4jGwaWc2D/VO3ifL2F9+nAk4AB/7ibg6fy74sfM7PBJ0icpDm/qt2vijFEhjid+gxvwyFa4p4tw2bR7bT9qWv/0K6P3Hadj8utF8JbZqRwqbnAIv832q0yuIJjV7T+agXeBaUwsaXQ+dFfA= Received: by 10.36.67.16 with SMTP id p16mr2213590nza; Tue, 02 May 2006 23:21:26 -0700 (PDT) Received: from ?10.1.1.23? ( [203.217.18.65]) by mx.gmail.com with ESMTP id 36sm5785nzk.2006.05.02.23.21.24; Tue, 02 May 2006 23:21:25 -0700 (PDT) Message-ID: <44584BE3.7020403@gmail.com> Date: Wed, 03 May 2006 16:21:23 +1000 From: Chris User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bert CC: pgsql-performance@postgresql.org Subject: Re: Easy question References: <1145741653.759727.38970@e56g2000cwe.googlegroups.com> <1146101167.724196.253740@v46g2000cwv.googlegroups.com> <1146355679.311472.57800@u72g2000cwu.googlegroups.com> In-Reply-To: <1146355679.311472.57800@u72g2000cwu.googlegroups.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200605/77 X-Sequence-Number: 18864 Bert wrote: > No i didn't defined any indexes for the table, I know the performance > will increase with an index, but this was not my question. My question > furthermore belongs to the access mode of the SQL statement. > Furthermore i do not understand why the Upper function should increase > the performance. The index will have entries like: CHRIS BERT JOE and so on. If you run a query like: select * from table where UPPER(name) = 'CHRIS'; It's an easy match. If you don't create an UPPER index, it has to do a comparison with each row - so the index can't be used because postgres has to convert the field to upper and then do the comparison. -- Postgresql & php tutorials http://www.designmagick.com/