X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 6C28456630 for ; Fri, 18 Mar 2005 00:06:03 +0000 (GMT) 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 29441-03 for ; Fri, 18 Mar 2005 00:06:01 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id 0D1C35660D for ; Fri, 18 Mar 2005 00:06:00 +0000 (GMT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j2I061W6028824; Thu, 17 Mar 2005 19:06:01 -0500 (EST) To: Theo Galanakis Cc: pgsql-sql@postgresql.org Subject: Re: Process priority. In-reply-to: References: Comments: In-reply-to Theo Galanakis message dated "Fri, 18 Mar 2005 10:32:48 +1100" Date: Thu, 17 Mar 2005 19:06:01 -0500 Message-ID: <28823.1111104361@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.007 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200503/253 X-Sequence-Number: 20732 Theo Galanakis writes: > I wrote a C program that can be called through postgres via stored > procedures. It allows you to change the current postmaster process priority. You are aware that that's widely considered either useless or counterproductive? Renice-ing one backend seldom gives helpful results, because (a) what usually matters more than CPU usage is I/O, and renice doesn't change I/O priorities; (b) priority inversion results in higher-priority backends blocking behind the low-priority one whenever it's managed to acquire a lock. regards, tom lane