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 1hYBOl-0004eY-Bp for pgsql-hackers@arkaria.postgresql.org; Tue, 04 Jun 2019 15:30:51 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1hYBOk-000138-8e for pgsql-hackers@arkaria.postgresql.org; Tue, 04 Jun 2019 15:30:50 +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 1hYBOj-000130-Vx for pgsql-hackers@lists.postgresql.org; Tue, 04 Jun 2019 15:30:50 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hYBOh-0004YW-QZ for pgsql-hackers@postgresql.org; Tue, 04 Jun 2019 15:30:49 +0000 Received: from pro.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id x54FUixG030213; Tue, 4 Jun 2019 11:30:44 -0400 From: Tom Lane To: Andrew Gierth cc: Christoph Berg , PostgreSQL Hackers Subject: Re: UCT (Re: pgsql: Update time zone data files to tzdata release 2019a.) In-reply-to: <87blzdacpp.fsf@news-spur.riddles.org.uk> References: <20190604085735.GD24018@msg.df7cb.de> <87blzdacpp.fsf@news-spur.riddles.org.uk> Comments: In-reply-to Andrew Gierth message dated "Tue, 04 Jun 2019 11:20:14 +0100" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <65810.1559662244.1@sss.pgh.pa.us> Date: Tue, 04 Jun 2019 11:30:44 -0400 Message-ID: <65811.1559662244@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Andrew Gierth writes: > I believe I pointed out a long, long time ago that this tie-breaking > strategy was insane, and that the rule should be to prefer canonical > names and use something else only in the case of a strictly better > match. This is assuming that the tzdb data has a concept of a canonical name for a zone, which unfortunately it does not. UTC, UCT, Etc/UTC, and about four other strings are equivalent names for the same zone so far as one can tell from the installed data. We could imagine layering some additional data on top of tzdb, but I don't much want to go there from a maintenance standpoint. regards, tom lane