Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id D6C8C9FB3E9 for ; Tue, 31 Oct 2006 16:23:06 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 32999-01 for ; Tue, 31 Oct 2006 20:22:13 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.207]) by postgresql.org (Postfix) with ESMTP id 3C8919FB3F6 for ; Tue, 31 Oct 2006 16:22:13 -0400 (AST) Received: by nz-out-0102.google.com with SMTP id i11so1686238nzi for ; Tue, 31 Oct 2006 12:22:12 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=nSlaaMSSjuk6sAxGiXccG4uS6CJUA1uHOub9iFKBoDfMuiqYhP81pdu0LWvEnPpZu6zwPFVAWH9CrDh085/7aXHRDELVEUaM/QUen7PS8NOrTTe7VfC1endUIo3LDm7yYFR0d65VUEvtv8St100RDG9mDj0fkGJ4+Ph04SzSgtk= Received: by 10.35.93.15 with SMTP id v15mr7429177pyl; Tue, 31 Oct 2006 12:22:12 -0800 (PST) Received: by 10.35.49.10 with HTTP; Tue, 31 Oct 2006 12:22:11 -0800 (PST) Message-ID: Date: Tue, 31 Oct 2006 16:22:11 -0400 From: "Worky Workerson" To: "Jim C. Nasby" Subject: Re: Best COPY Performance Cc: pgsql-performance@postgresql.org In-Reply-To: <20061026033448.GC26892@nasby.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <453C8B0D.4070803@logix-tt.com> <20061026033448.GC26892@nasby.net> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200610/629 X-Sequence-Number: 21758 > >I'm guessing the high bursts are checkpoints. Can you check your log > > >files for pg and see if you are getting warnings about checkpoint > > >frequency? You can get some mileage here by increasing wal files. > > > > Nope, nothing in the log. I have set: > > wal_buffers=128 > > checkpoint_segments=128 > > checkpoint_timeout=3000 > > which I thought was rather generous. Perhaps I should set it even > > higher for the loads? > > But depending on your shared_buffer and bgwriter settings (as well as > how much WAL traffic you're generating, you could still end up with big > slugs of work to be done when checkpoints happen. > > If you set checkpoint_warning to 3001, you'll see exactly when > checkpoints are happening, so you can determine if that's an issue. I did that, and I get two log messages, seeing checkpoints happening at 316 and 147 seconds apart on my load of a 1.9 GB file. Is this "an issue"? Thanks!