Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1b7oFr-000093-5L for pgsql-hackers@arkaria.postgresql.org; Tue, 31 May 2016 18:19:03 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1b7oFq-0004BO-EL for pgsql-hackers@arkaria.postgresql.org; Tue, 31 May 2016 18:19:02 +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 1b7oET-0007m3-LU for pgsql-hackers@postgresql.org; Tue, 31 May 2016 18:17:37 +0000 Received: from out2-smtp.messagingengine.com ([66.111.4.26]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1b7oEQ-0004eQ-SF for pgsql-hackers@postgresql.org; Tue, 31 May 2016 18:17:36 +0000 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id EADD226B71; Tue, 31 May 2016 14:17:33 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute3.internal (MEProxy); Tue, 31 May 2016 14:17:34 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-sasl-enc:x-sasl-enc; s=smtpout; bh=RS9hDV2HImpp9kx 38zJltKpzlFc=; b=BUoU3nZs070XgwgAt0qWGJ4s4p5tXIyp/WaRmig5dWzFy4a /8bucPqJnCJeKinN5D7xVRHIdolD1SuEB3bPpkXs29sQt1DeL1lz84KLKyuQYbRW OXuhrN1ps45zzbgWTgzDQvKIGR+z3iQgWhKYozFbwXUxCoFcA97wpVP0YDOg= X-Sasl-enc: CX/9y8t4rKtqZvDLTIm85S/TWTX5TLQltbkXRn0pIiim 1464718653 Received: from april.local (c-73-13-66-39.hsd1.pa.comcast.net [73.13.66.39]) by mail.messagingengine.com (Postfix) with ESMTPA id 6B235F2A0A; Tue, 31 May 2016 14:17:33 -0400 (EDT) Subject: Re: Rename max_parallel_degree? To: Josh berkus , Peter Geoghegan References: <20160426152217.GA548975@alvherre.pgsql> <574DBEA4.9000205@agliodbs.com> <8716.1464714201@sss.pgh.pa.us> <574DC585.7010507@agliodbs.com> <574DC881.5010006@agliodbs.com> <574DCDFC.6060506@agliodbs.com> <574DD1CE.2000307@agliodbs.com> Cc: Tom Lane , Robert Haas , Noah Misch , David Rowley , Amit Kapila , Alvaro Herrera , Magnus Hagander , Bruce Momjian , PostgreSQL-development From: Peter Eisentraut Organization: 2ndQuadrant Message-ID: Date: Tue, 31 May 2016 14:17:32 -0400 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <574DD1CE.2000307@agliodbs.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -2.6 (--) 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 5/31/16 2:02 PM, Josh berkus wrote: > I get where you're coming from, but I think Haas's query plan output is > going to show us the confusion we're going to get. So we need to either > change the parameter, the explain output, or brace ourselves for endless > repeated questions. Changing the explain output doesn't sound so bad to me. The users' problem is that the parameter setting ought to match the EXPLAIN output. The developers' problem is that the EXPLAIN output actually corresponds to leader + (N-1) workers internally. I think we can hope that developers are going to be less confused about that than users. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers