Received: from localhost (maia-4.hub.org [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id A3AF49FB24A for ; Tue, 28 Nov 2006 15:07:30 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-new, port 10024) with ESMTP id 86836-04 for ; Tue, 28 Nov 2006 15:07:12 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 54FA09FB1CF for ; Tue, 28 Nov 2006 15:07:12 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id kASJ75lJ004940; Tue, 28 Nov 2006 14:07:05 -0500 (EST) To: carlos.reimer@opendb.com.br cc: "Jim C. Nasby" , "Brad Nicholson" , pgsql-performance@postgresql.org Subject: Re: RES: Priority to a mission critical transaction In-reply-to: References: Comments: In-reply-to "Carlos H. Reimer" message dated "Tue, 28 Nov 2006 17:01:25 -0200" Date: Tue, 28 Nov 2006 14:07:05 -0500 Message-ID: <4939.1164740825@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/253 X-Sequence-Number: 22023 "Carlos H. Reimer" writes: > There is an article about "Lowering the priority of a PostgreSQL query" > (http://weblog.bignerdranch.com/?p=11) that explains how to use the > setpriority() to lower PostgreSQL processes. > I?m wondering how much effective it would be for i/o bound systems. That article isn't worth the electrons it's written on. Aside from the I/O point, there's a little problem called "priority inversion". See the archives for (many) past discussions of nice'ing backends. regards, tom lane