X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id DEB819DCB4C for ; Wed, 7 Dec 2005 00:34:07 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 28281-01 for ; Wed, 7 Dec 2005 00:34:06 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from candle.pha.pa.us (candle.pha.pa.us [64.139.89.126]) by postgresql.org (Postfix) with ESMTP id 79EF49DCB44 for ; Wed, 7 Dec 2005 00:34:05 -0400 (AST) Received: (from pgman@localhost) by candle.pha.pa.us (8.11.6/8.11.6) id jB74Y4o20004; Tue, 6 Dec 2005 23:34:04 -0500 (EST) From: Bruce Momjian Message-Id: <200512070434.jB74Y4o20004@candle.pha.pa.us> Subject: Re: High context switches occurring In-Reply-To: <22673.1133912703@sss.pgh.pa.us> To: Tom Lane Date: Tue, 6 Dec 2005 23:34:04 -0500 (EST) CC: Anjan Dave , Vivek Khera , Postgresql Performance X-Mailer: ELM [version 2.4ME+ PL121 (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.007 required=5 tests=[AWL=0.007] X-Spam-Score: 0.007 X-Spam-Level: X-Archive-Number: 200512/219 X-Sequence-Number: 16040 Tom Lane wrote: > "Anjan Dave" writes: > > -bash-3.00$ time pgbench -c 1000 -t 30 pgbench > > starting vacuum...end. > > transaction type: TPC-B (sort of) > > scaling factor: 1 > > number of clients: 1000 > > number of transactions per client: 30 > > number of transactions actually processed: 30000/30000 > > tps = 45.871234 (including connections establishing) > > tps = 46.092629 (excluding connections establishing) > > I can hardly think of a worse way to run pgbench :-(. These numbers are > about meaningless, for two reasons: > > 1. You don't want number of clients (-c) much higher than scaling factor > (-s in the initialization step). The number of rows in the "branches" > table will equal -s, and since every transaction updates one Should we throw a warning when someone runs the test this way? -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073