X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 723FF5286A for ; Tue, 19 Jul 2005 12:44:41 -0300 (ADT) 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 62414-03 for ; Tue, 19 Jul 2005 15:44:39 +0000 (GMT) Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.204]) by svr1.postgresql.org (Postfix) with ESMTP id 1BFB35285B for ; Tue, 19 Jul 2005 12:44:36 -0300 (ADT) Received: by wproxy.gmail.com with SMTP id 57so1223174wri for ; Tue, 19 Jul 2005 08:44:36 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=uPps7EP+uLyRHLl77uFz1KEljA8tvCkvzVdw35RgQpCpfXmO3rly/UduK0PemS6d24rtN7ycDz1H3cZc8yItj85cQl+5AzcmfjQ+Cb/dledHobUeaGGWWceRVzm3unWSgBM1OqJYkMApuej/CL//bLl+WlyOMCLL6ah9bgP3fms= Received: by 10.54.24.49 with SMTP id 49mr773923wrx; Tue, 19 Jul 2005 08:44:00 -0700 (PDT) Received: by 10.54.120.11 with HTTP; Tue, 19 Jul 2005 08:44:00 -0700 (PDT) Message-ID: <59d991c4050719084460b376f1@mail.gmail.com> Date: Tue, 19 Jul 2005 11:44:00 -0400 From: Christopher Petrilli Reply-To: Christopher Petrilli To: PFC , Vivek Khera , Tom Lane Subject: Re: Impact of checkpoint_segments under continual load conditions Cc: pgsql-performance@postgresql.org In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <59d991c4050717100874c08a86@mail.gmail.com> <59d991c405071811457ccdd3f1@mail.gmail.com> <16394.1121715156@sss.pgh.pa.us> <59d991c405071812342e290f57@mail.gmail.com> <16794.1121718743@sss.pgh.pa.us> <59d991c405071907482bb0689b@mail.gmail.com> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.161 tagged_above=0 required=5 tests=AWL, RCVD_BY_IP X-Spam-Level: X-Archive-Number: 200507/283 X-Sequence-Number: 13524 On 7/19/05, PFC wrote: >=20 > What happens if, say at iteration 6000 (a bit after the mess star= ts), you > pause it for a few minutes and resume. Will it restart with a plateau lik= e > at the beginning of the test ? or not ? Not sure... my benchmark is designed to represent what the database will do under "typical" circumstances, and unfortunately these are typical for the application. However, I can see about adding some delays, though multiple minutes would be absurd in the application.=20 Perhaps a 5-10 second day? Would that still be interesting? > What if, during this pause, you disconnect and reconnect, or rest= art the > postmaster, or vacuum, or analyze ? Well, I don't have the numbers any more, but restarting the postmaster has no effect, other than the first few hundreds COPYs are worse than anything (3-4x slower), but then it goes back to following the trend line. The data in the chart for v8.0.3 includes running pg_autovacuum (5 minutes). Chris --=20 | Christopher Petrilli | petrilli@gmail.com