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 1gZ9FU-00005H-Vq for pgsql-hackers@arkaria.postgresql.org; Tue, 18 Dec 2018 06:53:02 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gZ9FT-0004Sl-3x for pgsql-hackers@arkaria.postgresql.org; Tue, 18 Dec 2018 06:52:59 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gZ9FS-0004Sc-Lr for pgsql-hackers@lists.postgresql.org; Tue, 18 Dec 2018 06:52:58 +0000 Received: from mail.postgrespro.ru ([93.174.131.138]) by makus.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gZ9FO-0003gQ-Sz for pgsql-hackers@postgresql.org; Tue, 18 Dec 2018 06:52:57 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.postgrespro.ru (Postfix) with ESMTP id 3497821D342F; Tue, 18 Dec 2018 09:52:52 +0300 (MSK) X-Virus-Scanned: Debian amavisd-new at postgrespro.ru X-Spam-Flag: NO X-Spam-Score: 0 X-Spam-Level: X-Spam-Status: No, score=x tagged_above=-99 required=4 WHITELISTED tests=[] autolearn=unavailable Received: from [192.168.43.27] (unknown [176.59.192.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mail.postgrespro.ru (Postfix) with ESMTPSA id 9D3BA21D32E8; Tue, 18 Dec 2018 09:52:51 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=postgrespro.ru; s=mail; t=1545115972; bh=g6eF54r/venfj+dDvfCafo3SziE5o0W94BVmuRdJa1Q=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=GhrsKNjAB236cwZ3/wFKwNHkHW3dHZYc/RmBsYIYCl8KOB3arUpTiX8TKFHKUVAMk X6MyQ7cEavCiAq7mlYQwOmQwkP1K9EcAixqUqdbDprnMpqoBDhromjq7pKgNo1y0zj Hn0km3I28AjxuxDYr/U0sAHyJ+JPbDguH9dTzgso= Subject: Re: Fixing findDependentObjects()'s dependency on scan order (regressions in DROP diagnostic messages) To: Peter Geoghegan Cc: Peter Eisentraut , Alvaro Herrera , PostgreSQL Hackers References: <0a89eb40-ea89-9037-aad0-3b65c67cdcbd@postgrespro.ru> <65ced322-84d2-777a-2fac-5f482c175431@postgrespro.ru> <3294d285-d3b3-e159-b3f7-6c2d1b059956@postgrespro.ru> From: Andrey Lepikhov Organization: Postgres Professional Message-ID: <0388ee45-abfa-d419-f502-f9527efdb8a4@postgrespro.ru> Date: Tue, 18 Dec 2018 11:52:50 +0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 08.12.2018 6:58, Peter Geoghegan wrote: > I have no idea what you mean here. I'm proposing a patch that stops > it being a game of chance, while preserving the existing > slightly-random behavior to the greatest extent possible. I think that > my patch would have stopped that problem altogether. Are you > suggesting that it wouldn't have? I did many tests of your solution inside the 'quick vacuum' strategy [1] and the background worker called 'heap cleaner' [2]. I must admit that when I use your patch, there is no problem with dependencies. This patch needs opinion of an another reviewer. [1] https://www.postgresql.org/message-id/425db134-8bba-005c-b59d-56e50de3b41e%40postgrespro.ru [2] https://www.postgresql.org/message-id/f49bb262-d246-829d-f835-3950ddac503c%40postgrespro.ru -- Andrey Lepikhov Postgres Professional https://postgrespro.com The Russian Postgres Company