Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1he3at-0002HG-3V for pgsql-hackers@arkaria.postgresql.org; Thu, 20 Jun 2019 20:23:39 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1he3aq-0007DE-Un for pgsql-hackers@arkaria.postgresql.org; Thu, 20 Jun 2019 20:23:36 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1he3aq-0007D6-Lt for pgsql-hackers@lists.postgresql.org; Thu, 20 Jun 2019 20:23:36 +0000 Received: from lungold.riddles.org.uk ([82.68.208.19]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1he3aj-00048N-Vn for pgsql-hackers@postgresql.org; Thu, 20 Jun 2019 20:23:36 +0000 Received: from [192.168.127.1] (port=58314 helo=caithnard.riddles.org.uk) by lungold.riddles.org.uk with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.88 (FreeBSD)) (envelope-from ) id 1he3ag-000JOm-BH; Thu, 20 Jun 2019 20:23:26 +0000 Received: from [127.0.0.1] (port=46230 helo=caithnard.riddles.org.uk) by caithnard.riddles.org.uk with esmtp (Exim 4.89 (FreeBSD)) (envelope-from ) id 1he3af-000G11-Mu; Thu, 20 Jun 2019 20:23:25 +0000 From: Andrew Gierth To: Tom Lane Cc: Stephen Frost , Robert Haas , Alvaro Herrera , Andres Freund , Christoph Berg , PostgreSQL Hackers Subject: Re: UCT (Re: pgsql: Update time zone data files to tzdata release 2019a.) In-Reply-To: <22384.1561060731@sss.pgh.pa.us> (Tom Lane's message of "Thu, 20 Jun 2019 15:58:51 -0400") Message-ID: <87tvckypr5.fsf@news-spur.riddles.org.uk> References: <20190620161400.6wtuybv64ihnfy6d@alap3.anarazel.de> <20190620172838.GA21945@alvherre.pgsql> <20190620182406.GD2480@tamriel.snowman.net> <87y31wytdl.fsf@news-spur.riddles.org.uk> <20190620192412.GG2480@tamriel.snowman.net> <22384.1561060731@sss.pgh.pa.us> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (berkeley-unix) Date: Thu, 20 Jun 2019 21:23:25 +0100 MIME-Version: 1.0 Content-Type: text/plain List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk >>>>> "Tom" == Tom Lane writes: >> I was referring to the fact that the regression was introduced by a, >> presumably important, tzdb update (2019a, as mentioned above). At >> least, I made the assumption that the commit of the import of 2019a >> had more than just the change that introduced the regression, but >> I'm happy to admit I'm no where near as close to the code here as >> you/Tom here. Tom> Keep in mind that dealing with whatever tzdb chooses to ship is Tom> not optional from our standpoint. Even if we'd refused to import Tom> 2019a, every installation using --with-system-tzdata (which, I Tom> sincerely hope, includes most production installs) is going to Tom> have to deal with it as soon as the respective platform vendor Tom> gets around to shipping the tzdata update. So reverting that Tom> commit was never on the table. Exactly. But that means that if the combination of our arbitrary rules and the data in the tzdb results in an undesirable result, then we have no real option but to fix our rules (we can't reasonably expect the tzdb upstream to choose zone names to make our alphabetical-order preference come out right). My commit was intended to be the minimum fix that would restore the pre-2019a behavior on all systems. -- Andrew (irc:RhodiumToad)