Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n5U0p-0006B1-Ox for pgsql-hackers@arkaria.postgresql.org; Thu, 06 Jan 2022 14:45:07 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1n5U0o-0008RA-DY for pgsql-hackers@arkaria.postgresql.org; Thu, 06 Jan 2022 14:45:06 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n5U0o-0008R0-40 for pgsql-hackers@lists.postgresql.org; Thu, 06 Jan 2022 14:45:06 +0000 Received: from relay3-d.mail.gandi.net ([217.70.183.195]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n5U0l-0004az-Hd for pgsql-hackers@lists.postgresql.org; Thu, 06 Jan 2022 14:45:05 +0000 Received: (Authenticated sender: vik@postgresfriends.org) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 8BAC960006; Thu, 6 Jan 2022 14:44:59 +0000 (UTC) Subject: Re: SQL:2011 application time To: Corey Huinker , Peter Eisentraut Cc: Paul A Jungwirth , Jaime Casanova , PostgreSQL Hackers References: <20210904195556.GA10553@ahch-to> <20210911015017.GA8837@ahch-to> <5650d77a-1d73-fd8d-4410-8e97dbeff572@illuminatedcomputing.com> <21964319-46e5-3e47-217b-6ac4169bdf13@enterprisedb.com> From: Vik Fearing Message-ID: <846b2f26-b4ff-e463-7aff-102f2683a111@postgresfriends.org> Date: Thu, 6 Jan 2022 15:44:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On 1/5/22 11:03 PM, Corey Huinker wrote: > > There was similar work being done for system periods, which are a bit > simpler but require a side (history) table to be created. This is false. SYSTEM_TIME periods do not need any kind of history. This was one of the problems I had with Surafel's attempt because it was confusing the period with SYSTEM VERSIONING. Versioning needs the period but the inverse is not true. -- Vik Fearing