Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VCUP9-0004Xd-3X for pgsql-hackers@arkaria.postgresql.org; Thu, 22 Aug 2013 12:54:23 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1VCUP8-0005uC-CV for pgsql-hackers@arkaria.postgresql.org; Thu, 22 Aug 2013 12:54:22 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VCUP6-0005rn-I7 for pgsql-hackers@postgresql.org; Thu, 22 Aug 2013 12:54:20 +0000 Received: from mimolette.dalibo.net ([212.85.154.222]) by makus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VCUP3-0001z2-Rw for pgsql-hackers@postgresql.org; Thu, 22 Aug 2013 12:54:19 +0000 Received: from [192.168.0.38] (ip-68.net-81-220-133.standre.rev.numericable.fr [81.220.133.68]) by mimolette.dalibo.net (Postfix) with ESMTPSA id 5E91A4502872; Thu, 22 Aug 2013 14:54:15 +0200 (CEST) Message-ID: <521609DB.3080807@dalibo.com> Date: Thu, 22 Aug 2013 14:53:47 +0200 From: Vik Fearing User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Fujii Masao CC: PG Hackers Subject: Re: pg_system_identifier() References: <5215346B.7070800@dalibo.com> 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 08/22/2013 02:51 PM, Fujii Masao wrote: > On Thu, Aug 22, 2013 at 6:43 AM, Vik Fearing wrote: >> After someone in IRC asked if there was an equivalent to MySQL's >> server_id, it was noted that we do have a system identifier but it's not >> very accessible. >> >> The attached patch implements a pg_system_identifier() function that >> exposes it. > What's the use case? It's information about the server that's only accessible through pg_controldata. I don't know if that's justification enough, which is why I didn't add it to the commitfest yet. > IIUC, PostgreSQL's system identifier is not equal to MySQL server-id. > In PostgreSQL, in replication, the master and all the standbys must > have the same system identifier. OTOH, in MySQL, they have the different > server-ids. No? I have zero experience with MySQL. -- Vik -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers