X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 3538C52BC1 for ; Wed, 13 Jul 2005 05:20:58 -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 58554-01 for ; Wed, 13 Jul 2005 08:20:54 +0000 (GMT) Received: from nproxy.gmail.com (nproxy.gmail.com [64.233.182.203]) by svr1.postgresql.org (Postfix) with ESMTP id 8D2D652862 for ; Wed, 13 Jul 2005 05:20:52 -0300 (ADT) Received: by nproxy.gmail.com with SMTP id n15so24528nfc for ; Wed, 13 Jul 2005 01:20:51 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=rnErMerhImKEqUJ/Pe9i+Nhhyr2f/GIxNOp1FUQVyQsz4052XNArVeK1PZv0HOi+oonaHPgiUVp03WlyFpaIv6SliEUzzSkqPSb9sbst+agUWcAS1fYCU7IHhrGoq8qL6phS5n4izai9gbQbRnHK+ThZ+2banSp4Hhk/koUkNSU= Received: by 10.48.237.12 with SMTP id k12mr17690nfh; Wed, 13 Jul 2005 01:20:51 -0700 (PDT) Received: by 10.48.49.14 with HTTP; Wed, 13 Jul 2005 01:20:51 -0700 (PDT) Message-ID: <4b09a0c05071301207d452ace@mail.gmail.com> Date: Wed, 13 Jul 2005 10:20:51 +0200 From: Jean-Max Reymond Reply-To: Jean-Max Reymond To: pgsql-performance@postgresql.org Subject: size of cache Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.069 tagged_above=0 required=5 tests=AWL, RCVD_BY_IP X-Spam-Level: X-Archive-Number: 200507/136 X-Sequence-Number: 13377 with my application, it seems that size of cache has great effect: from 512 Kb of L2 cache to 1Mb boost performance with a factor 3 and 20% again from 1Mb L2 cache to 2Mb L2 cache. I don't understand why a 512Kb cache L2 is too small to fit the data's does it exist a tool to trace processor activity and confirm that processor is waiting for memory ? does it exist a tool to snapshot postgres activity and understand where we spend time and potentialy avoid the bottleneck ? thanks for your tips. --=20 Jean-Max Reymond CKR Solutions Open Source Nice France http://www.ckr-solutions.com