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 1gUwa5-00074r-Sc for pgsql-hackers@arkaria.postgresql.org; Thu, 06 Dec 2018 16:32:54 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gUwa3-0003hu-AK for pgsql-hackers@arkaria.postgresql.org; Thu, 06 Dec 2018 16:32:51 +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 1gUwa2-0003gv-RZ for pgsql-hackers@lists.postgresql.org; Thu, 06 Dec 2018 16:32:50 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gUwZz-0006zw-Rs for pgsql-hackers@postgresql.org; Thu, 06 Dec 2018 16:32:49 +0000 Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id wB6GWgxm020578; Thu, 6 Dec 2018 11:32:42 -0500 From: Tom Lane To: Robert Haas cc: Andres Freund , Pavel Stehule , "pgsql-hackers@postgresql.org" Subject: Re: slow queries over information schema.tables In-reply-to: References: <5978.1544030694@sss.pgh.pa.us> <20181205175657.s7mt6as356kwvrji@alap3.anarazel.de> <8210.1544034143@sss.pgh.pa.us> <20181205182555.x4wtnzffmhwsc3c7@alap3.anarazel.de> <8843.1544035292@sss.pgh.pa.us> Comments: In-reply-to Robert Haas message dated "Thu, 06 Dec 2018 11:19:00 -0500" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <20576.1544113962.1@sss.pgh.pa.us> Date: Thu, 06 Dec 2018 11:32:42 -0500 Message-ID: <20577.1544113962@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Robert Haas writes: > I'm not thrilled about depending on sinval without locking, > particularly given that my proposal to make sure we > AcceptInvalidationMessages() at least once per query was shouted down. It's fairly hard to imagine practical cases where we'd not call AcceptInvalidationMessages at least once per query, so I'm not very sure what you're on about. regards, tom lane