Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1XMPaK-0001Hw-5t for pgsql-hackers@arkaria.postgresql.org; Tue, 26 Aug 2014 22:51:28 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1XMPaJ-000339-HQ for pgsql-hackers@arkaria.postgresql.org; Tue, 26 Aug 2014 22:51:27 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1XMPaG-00032x-Uf for pgsql-hackers@postgresql.org; Tue, 26 Aug 2014 22:51:25 +0000 Received: from mail.catalyst.net.nz ([2404:130:0:10::40:0]) by magus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1XMPa9-0001IX-7C for pgsql-hackers@postgresql.org; Tue, 26 Aug 2014 22:51:22 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.catalyst.net.nz (Postfix) with ESMTP id 8DBB232D23; Wed, 27 Aug 2014 10:51:11 +1200 (NZST) X-Virus-Scanned: Debian amavisd-new at catalyst.net.nz Received: from mail.catalyst.net.nz ([127.0.0.1]) by localhost (bertrand.catalyst.net.nz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id M9o0qq+2SImb; Wed, 27 Aug 2014 10:51:11 +1200 (NZST) Received: from [192.168.1.64] (122-62-5-20.jetstream.xtra.co.nz [122.62.5.20]) (Authenticated sender: mark.kirkwood) by mail.catalyst.net.nz (Postfix) with ESMTPSA id D131A3273E; Wed, 27 Aug 2014 10:51:10 +1200 (NZST) Message-ID: <53FD0F5F.7000002@catalyst.net.nz> Date: Wed, 27 Aug 2014 10:51:11 +1200 From: Mark Kirkwood User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Alvaro Herrera CC: Amit Kapila , Haribabu Kommi , "pgsql-hackers@postgresql.org" Subject: Re: Per table autovacuum vacuum cost limit behaviour strange References: <20140214213227.GF6342@eldon.alvh.no-ip.org> <53672F63.3080400@catalyst.net.nz> <53686F22.8030300@catalyst.net.nz> <20140826161911.GE6343@eldon.alvh.no-ip.org> <20140826222700.GA23139@eldon.alvh.no-ip.org> In-Reply-To: <20140826222700.GA23139@eldon.alvh.no-ip.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org On 27/08/14 10:27, Alvaro Herrera wrote: > Alvaro Herrera wrote: > >> So my proposal is a bit more complicated. First we introduce the notion >> of a single number, to enable sorting and computations: the "delay >> equivalent", which is the cost_limit divided by cost_delay. > > Here's a patch that implements this idea. As you see this is quite a > bit more complicated that Haribabu's proposal. > > There are two holes in this: > > 1. if you ALTER DATABASE to change vacuum delay for a database, those > values are not considered in the global equiv delay. I don't think this > is very important and anyway we haven't considered this very much, so > it's okay if we don't handle it. > > 2. If you have a "fast worker" that's only slightly faster than regular > workers, it will become slower in some cases. This is explained in a > FIXME comment in the patch. > > I don't really have any more time to invest in this, but I would like to > see it in 9.4. Mark, would you test this? Haribabu, how open are you > to fixing point (2) above? > Thanks Alvaro - I will take a look. regards Mark -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers