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 1lKyGq-0000P0-Vc for pgsql-hackers@arkaria.postgresql.org; Sat, 13 Mar 2021 07:01:08 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1lKyGp-0008P7-IU for pgsql-hackers@arkaria.postgresql.org; Sat, 13 Mar 2021 07:01:07 +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 1lKyGp-0008N5-BM for pgsql-hackers@lists.postgresql.org; Sat, 13 Mar 2021 07:01:07 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by magus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lKyGl-0003Th-VN for pgsql-hackers@postgresql.org; Sat, 13 Mar 2021 07:01:06 +0000 Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.15.2/8.15.2) with ESMTP id 12D70tAF2592091; Sat, 13 Mar 2021 02:00:55 -0500 From: Tom Lane To: Mark Dilger cc: Noah Misch , Robert Haas , Peter Geoghegan , Thomas Munro , "Andrey M. Borodin" , Stephen Frost , Michael Paquier , Amul Sul , Dilip Kumar , Andres Freund , PostgreSQL-development Subject: Re: pg_amcheck contrib application In-reply-to: <1911287A-3420-4C23-ACF7-4D92EA580B70@enterprisedb.com> References: <9E76E46A-48B2-4869-BD0C-422204C1F767@enterprisedb.com> <2574324.1615611372@sss.pgh.pa.us> <2588078.1615613250@sss.pgh.pa.us> <2589781.1615615635@sss.pgh.pa.us> <20210313061655.GC3099026@rfd.leadboat.com> <6BBDE6C1-3F40-4009-896D-9CA9D87BEC9A@enterprisedb.com> <2590503.1615616574@sss.pgh.pa.us> <2591070.1615617371@sss.pgh.pa.us> <1911287A-3420-4C23-ACF7-4D92EA580B70@enterprisedb.com> Comments: In-reply-to Mark Dilger message dated "Fri, 12 Mar 2021 22:55:11 -0800" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2592089.1615618855.1@sss.pgh.pa.us> Content-Transfer-Encoding: quoted-printable Date: Sat, 13 Mar 2021 02:00:55 -0500 Message-ID: <2592090.1615618855@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk Mark Dilger writes: > On Mar 12, 2021, at 10:36 PM, Tom Lane wrote: >> You might think about using some symmetric-but-not-zero value, >> 0x01010101 or the like. > I thought about that, but I'm not sure that it proves much more than jus= t using zero. Perhaps not. I haven't really looked at any of this code, so I'll defer to Robert's judgment about whether this represents an interesting testing issue. regards, tom lane