Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1b8Diz-00080v-AE for pgsql-hackers@arkaria.postgresql.org; Wed, 01 Jun 2016 21:30:49 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1b8Diy-0000N7-Rd for pgsql-hackers@arkaria.postgresql.org; Wed, 01 Jun 2016 21:30:48 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1b8Dix-0000Jd-Am for pgsql-hackers@postgresql.org; Wed, 01 Jun 2016 21:30:47 +0000 Received: from zmcc-5-mx.zmailcloud.com ([192.198.93.228]) by makus.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1b8Diu-0000tO-QN for pgsql-hackers@postgresql.org; Wed, 01 Jun 2016 21:30:46 +0000 Received: from zmcc-5-mta-1.zmailcloud.com (127.37.197.104.bc.googleusercontent.com [104.197.37.127]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by zmcc-5-mx.zmailcloud.com (Postfix) with ESMTPS id 946AC52041B; Wed, 1 Jun 2016 17:30:43 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by zmcc-5-mta-1.zmailcloud.com (Postfix) with ESMTP id 3BDBDC216D; Wed, 1 Jun 2016 21:30:43 +0000 (UTC) Received: from zmcc-5-mta-1.zmailcloud.com ([127.0.0.1]) by localhost (zmcc-5-mta-1.zmailcloud.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 8O6PK6cI-48M; Wed, 1 Jun 2016 21:30:42 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by zmcc-5-mta-1.zmailcloud.com (Postfix) with ESMTP id CC2D5C2D1E; Wed, 1 Jun 2016 21:30:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at zmcc-5-mta-1.zmailcloud.com Received: from zmcc-5-mta-1.zmailcloud.com ([127.0.0.1]) by localhost (zmcc-5-mta-1.zmailcloud.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id ZAO3stHobIjt; Wed, 1 Jun 2016 21:30:42 +0000 (UTC) Received: from redhat.com (c-67-170-152-2.hsd1.or.comcast.net [67.170.152.2]) by zmcc-5-mta-1.zmailcloud.com (Postfix) with ESMTPSA id 04978C216D; Wed, 1 Jun 2016 21:30:41 +0000 (UTC) Subject: Re: Rename max_parallel_degree? To: Robert Haas , Tom Lane References: <20160426152217.GA548975@alvherre.pgsql> <574DBEA4.9000205@agliodbs.com> <8716.1464714201@sss.pgh.pa.us> <574DC585.7010507@agliodbs.com> <574DC881.5010006@agliodbs.com> <21146.1464717625@sss.pgh.pa.us> <17944.1464790245@sss.pgh.pa.us> Cc: Amit Kapila , Peter Geoghegan , Noah Misch , David Rowley , Alvaro Herrera , Magnus Hagander , Bruce Momjian , PostgreSQL-development From: Josh berkus Message-ID: <574F5400.3040507@agliodbs.com> Date: Wed, 1 Jun 2016 14:30:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 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 06/01/2016 02:21 PM, Robert Haas wrote: > If you lined up ten people in a room all of whom were competent > database professionals and none of whom knew anything about PostgreSQL > and asked them to guess what a setting called work_mem does and what a > setting called max_parallel_degree does, I will wager you $5 that > they'd do better on the second one. Likewise, I bet the guesses for > max_parallel_degree would be closer to the mark than the guesses for > maintenance_work_mem or replacement_sort_tuples or commit_siblings or > bgwriter_lru_multiplier. Incidentally, the reason I didn't jump into this thread until the patches showed up is that I don't think it actually matters what the parameters are named. They're going to require documentation regardless, parallism just isn't something people grok instinctively. I care about how the parameters *work*, and whether that's consistent across our various resource management settings. -- -- Josh Berkus Red Hat OSAS (any opinions are my own) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers