From oracle-l-bounce@freelists.org Fri Jul 9 00:58:09 2004 Return-Path: Received: from air189.startdedicated.com (root@localhost) by orafaq.com (8.11.6/8.11.6) with ESMTP id i695vcS10140 for ; Fri, 9 Jul 2004 00:57:48 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air189.startdedicated.com (8.11.6/8.11.6) with ESMTP id i695vS610116 for ; Fri, 9 Jul 2004 00:57:38 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id E2F0272C0FC; Fri, 9 Jul 2004 00:38:37 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 12972-23; Fri, 9 Jul 2004 00:38:37 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 38CF772C200; Fri, 9 Jul 2004 00:38:37 -0500 (EST) Received: with ECARTIS (v1.0.0; list oracle-l); Fri, 09 Jul 2004 00:37:13 -0500 (EST) X-Original-To: oracle-l@freelists.org Delivered-To: oracle-l@freelists.org Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 0F0DC72C050 for ; Fri, 9 Jul 2004 00:37:13 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 12448-13 for ; Fri, 9 Jul 2004 00:37:12 -0500 (EST) Received: from ross.alise.lv (ross.alise.lv [194.19.227.242]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 9764A72C03F for ; Fri, 9 Jul 2004 00:37:12 -0500 (EST) To: oracle-l@freelists.org Subject: IO subsystem speed & rule of thumb MIME-Version: 1.0 X-Mailer: Lotus Notes Release 6.5.2 June 01, 2004 Message-ID: From: J.Velikanovs@alise.lv Date: Fri, 9 Jul 2004 08:53:38 +0300 X-MIMETrack: Serialize by Router on ROSS/IT ALISE/LV(Release 5.0.11 |July 24, 2002) at 2004.07.09 08:53:40, Serialize complete at 2004.07.09 08:53:40 Content-type: text/plain X-Virus-Scanned: by amavisd-new at freelists.org Content-Transfer-Encoding: 8bit X-archive-position: 4733 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: J.Velikanovs@alise.lv Precedence: normal Reply-To: oracle-l@freelists.org X-list: oracle-l X-Virus-Scanned: by amavisd-new at freelists.org Hi! As we know modern IO subsystems can handle single IO by 20-5 ms. I know there are many factors like caching, cylinders, etc etc, but lets ignore them in context of this discussion. Then single (Oracle) process can issued (1sec/20-5ms) 50-200 IOs/sec (sequential reads). Lets assume that process work with large tables, and main access path is thought indexes. Some time (depending of algorithm) process will spend for data processing, lets assume ~50%. The conclusion is single process can issue maximum 25-100 PIO per second, depending of IO subsystem. My question is, can it be rule of thumb, for peoples who going to tune some batch processes? What is the opinion of audience? Thanks in advance, Jurijs PS I assume, that process requires a lot of PIO-s by business. PIO is main bottleneck. PPS Going to particular system we can estimate average speed of IO system, STATSPACK reports, as well as from 10046 for particular process PPPS Next question will be, how practically we can test IO system before running production on it? PPPPS How to estimate TOTAL PIO count that IO system can handle? ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------