X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 02C639FB265 for ; Wed, 9 Aug 2006 19:37:17 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 43717-01 for ; Wed, 9 Aug 2006 22:37:08 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 0350C9FB2D5 for ; Wed, 9 Aug 2006 19:37:07 -0300 (ADT) 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 k79Mb0db000920; Wed, 9 Aug 2006 18:37:00 -0400 (EDT) To: "Jim C. Nasby" cc: Christopher Browne , pgsql-performance@postgresql.org Subject: Re: shared_buffer optimization In-reply-to: <20060809212804.GU40481@pervasive.com> References: <44D86A00.90106@rentalia.com> <87u04nv2q6.fsf@wolfe.cbbrowne.com> <20060809212804.GU40481@pervasive.com> Comments: In-reply-to "Jim C. Nasby" message dated "Wed, 09 Aug 2006 16:28:04 -0500" Date: Wed, 09 Aug 2006 18:37:00 -0400 Message-ID: <919.1155163020@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200608/170 X-Sequence-Number: 20355 "Jim C. Nasby" writes: > Every single piece of advice I've seen on shared_buffers comes from the > 7.x era, when our buffer management was extremely simplistic. IMO all of > that knowledge was made obsolete when 8.0 came out, and our handling of > shared_buffers has improved ever further since then. This is definately > an area that could use a lot more testing. Actually I think it was probably 8.1 that made the significant difference there, by getting rid of the single point of contention for shared-buffer management. I concur that 7.x-era rules of thumb may well be obsolete --- we need some credible scaling tests ... regards, tom lane