Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1stZ4b-00HPJ8-Hj for pgsql-general@arkaria.postgresql.org; Wed, 25 Sep 2024 20:57:22 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1stZ4a-00EIdn-Ux for pgsql-general@arkaria.postgresql.org; Wed, 25 Sep 2024 20:57:20 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1stZ1R-00EChY-Cj for pgsql-general@lists.postgresql.org; Wed, 25 Sep 2024 20:54:05 +0000 Received: from smtp112.ord1d.emailsrvr.com ([184.106.54.112]) by makus.postgresql.org with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1stZ1O-00134M-UK for pgsql-general@lists.postgresql.org; Wed, 25 Sep 2024 20:54:04 +0000 X-Auth-ID: xof@thebuild.com Received: by smtp7.relay.ord1d.emailsrvr.com (Authenticated sender: xof-AT-thebuild.com) with ESMTPSA id 7F4242015E; Wed, 25 Sep 2024 16:54:01 -0400 (EDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3776.700.51\)) Subject: Re: Repeatable Read Isolation Level "transaction start time" From: Christophe Pettus In-Reply-To: Date: Wed, 25 Sep 2024 13:53:30 -0700 Cc: Ron Johnson , "pgsql-generallists.postgresql.org" Content-Transfer-Encoding: quoted-printable Message-Id: References: <9CEBFAC7-4372-4FF0-8124-FFFE834B03C6@gmail.com> <3346993.1727188126@sss.pgh.pa.us> <28109.1727286817@sss.pgh.pa.us> To: Greg Sabino Mullane X-Mailer: Apple Mail (2.3776.700.51) X-Classification-ID: ec72852e-f005-40f0-9cad-64b3abe139af-1-1 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk > On Sep 25, 2024, at 13:49, Greg Sabino Mullane = wrote: > BEGIN ISOLATION MODE REPEATABLE READ SNAPSHOT NOW; This might well be a failure of imagination on my part, but when would = it pragmatically matter that the snapshot is taken at the first = statement as opposed to at BEGIN?=