Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dQhf6-00007P-56 for pgsql-hackers@arkaria.postgresql.org; Thu, 29 Jun 2017 22:11:44 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1dQhf5-00019s-1C for pgsql-hackers@arkaria.postgresql.org; Thu, 29 Jun 2017 22:11:43 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1dQhdW-0006m4-5v for pgsql-hackers@postgresql.org; Thu, 29 Jun 2017 22:10:06 +0000 Received: from bay.acenet.us ([173.230.252.50]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1dQhdT-00034s-2I for pgsql-hackers@postgresql.org; Thu, 29 Jun 2017 22:10:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=anastigmatix.net; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:Cc:References:To:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=gOa+qZRE8zMFG8Ji1lYP1eXmKMDmCO2gMG8Xqkxx4II=; b=lOsw49OBB7oDOf5ncco134qOX7 fhh+S2+gEOLsjuKjRH/EgzSHtpioMgROfatAAa2nZcbwyVlNi3vWuUfHj77qnFweXCTi7kX21jKwY MgQuYwILAm6cp0nGz2mLCxyRHzw/igSTRp5wkuJRE4uRhNzCexuK46mHC83AjDLAK05L0uJCme+03 Ujr4fD73F2NLqEacN+xuJxuhuUZqhazFXnKyn0Hsqge3hc468Fek8gkEXG8zfEBt+fffkZJ4U3nWC 5PT4YueH1T48/wWg1qqWYlM/DsgTENQZ84LOLTzAXI5W/8tX50PQKUUtHkV8F0IHGEE6Bhdo44mjG H5XRLRAg==; Received: from [50.102.16.86] (port=47864) by bay.acenet.us with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.89) (envelope-from ) id 1dQhdQ-001aBb-H3; Thu, 29 Jun 2017 18:10:01 -0400 Subject: Re: AdvanceXLInsertBuffer vs. WAL segment compressibility To: Heikki Linnakangas , Robert Haas , Bruce Momjian References: <579297F8.7020107@anastigmatix.net> <5797D953.6040806@anastigmatix.net> <20160802183347.GD32575@momjian.us> <20943eba-bbb9-390c-01b1-e6704ce33c7b@iki.fi> <594C9457.6000708@anastigmatix.net> <59506148.1010708@anastigmatix.net> Cc: PostgreSQL Hackers From: Chapman Flack Message-ID: <59557AB7.1060203@anastigmatix.net> Date: Thu, 29 Jun 2017 18:09:59 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <59506148.1010708@anastigmatix.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-OutGoing-Spam-Status: No, score=-100.2 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bay.acenet.us X-AntiAbuse: Original Domain - postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - anastigmatix.net X-Get-Message-Sender-Via: bay.acenet.us: authenticated_id: chap+anastigmatix.net/only user confirmed/virtual account not confirmed X-Authenticated-Sender: bay.acenet.us: chap@anastigmatix.net X-Source: X-Source-Args: X-Source-Dir: List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org On 06/25/17 21:20, Chapman Flack wrote: > I want to make sure I understand what the deadlock potential is > in this case. AdvanceXLInsertBuffer will call WaitXLogInsertionsToFinish > ... > Does not the fact we hold all the insertion slots exclude the possibility > that any dirty buffer (preceding the one we're touching) needs to be checked > for in-flight insertions? [in the filling-out-the-log-tail case only] Anyone? Or have I not even achieved 'wrong' yet? -Chap -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers