X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 3B315DB5DE for ; Tue, 1 Nov 2005 04:03:13 -0400 (AST) 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 21020-10 for ; Tue, 1 Nov 2005 08:03:10 +0000 (GMT) Received: from obelix.askesis.nl (laudanum.demon.nl [82.161.125.16]) by svr1.postgresql.org (Postfix) with ESMTP id 581F7DB309 for ; Tue, 1 Nov 2005 04:03:10 -0400 (AST) Received: obelix.askesis.nl 172.31.0.1 from 172.31.1.8 172.31.1.8 via HTTP with MS-WebStorage 6.0.6249 Received: from Panoramix by obelix.askesis.nl; 01 Nov 2005 09:03:10 +0100 Subject: pgbench results interpretation? From: Joost Kraaijeveld To: Pgsql-Performance Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Tue, 01 Nov 2005 09:03:09 +0100 Message-Id: <1130832189.21036.19.camel@Panoramix> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.074 required=5 tests=[AWL=0.073, UNPARSEABLE_RELAY=0.001] X-Spam-Score: 0.074 X-Spam-Level: X-Archive-Number: 200511/1 X-Sequence-Number: 15258 Hi, I am trying to optimize my Debian Sarge AMD64 PostgreSQL 8.0 installation, based on the recommendations from "the Annotated POSTGRESQL.CONF Guide for PostgreSQL" (http://www.powerpostgresql.com/Downloads/annotated_conf_80.html). To see the result of the recommendations I use pgbench from postgresql-contrib. I have 3 questions about pgbench: 1. Is there a repository somewhere that shows results, using and documenting different kinds of hard- and software setups so that I can compare my results with someone elses? 2. Is there a reason for the difference in values from run-to-run of pgbench: The command I used (nothing else is done on the machine, not even mouse movement): jkr@Panoramix:/usr/lib/postgresql/8.0/bin$ ./pgbench -c 10 -t 1000 test Results for 4 consecutive runs: tps = 272.932982 (including connections establishing) tps = 273.262622 (excluding connections establishing) tps = 199.501426 (including connections establishing) tps = 199.674937 (excluding connections establishing) tps = 400.462117 (including connections establishing) tps = 401.218291 (excluding connections establishing) tps = 223.695331 (including connections establishing) tps = 223.919031 (excluding connections establishing) 3. It appears that running more transactions with the same amount of clients leads to a drop in the transactions per second. I do not understand why this is (a drop from more clients I do understand). Is this because of the way pgbench works, the way PostgrSQL works or even Linux? jkr@Panoramix:/usr/lib/postgresql/8.0/bin$ ./pgbench -c 10 -t 10 test tps = 379.218809 (including connections establishing) tps = 461.968448 (excluding connections establishing) jkr@Panoramix:/usr/lib/postgresql/8.0/bin$ ./pgbench -c 10 -t 100 test tps = 533.878031 (including connections establishing) tps = 546.571141 (excluding connections establishing) jkr@Panoramix:/usr/lib/postgresql/8.0/bin$ ./pgbench -c 10 -t 1000 test tps = 204.344440 (including connections establishing) tps = 204.533627 (excluding connections establishing) jkr@Panoramix:/usr/lib/postgresql/8.0/bin$ ./pgbench -c 10 -t 10000 test tps = 121.486803 (including connections establishing) tps = 121.493681 (excluding connections establishing) TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 e-mail: J.Kraaijeveld@Askesis.nl web: www.askesis.nl