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 1jZJnj-0000RB-3F for pgsql-hackers@arkaria.postgresql.org; Thu, 14 May 2020 19:45:51 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1jZJnh-0003TC-Vk for pgsql-hackers@arkaria.postgresql.org; Thu, 14 May 2020 19:45:49 +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 1jZJnh-0003R7-OU for pgsql-hackers@lists.postgresql.org; Thu, 14 May 2020 19:45:49 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jZJnf-0002gR-LG for pgsql-hackers@postgresql.org; Thu, 14 May 2020 19:45:49 +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 04EJjQtw013488; Thu, 14 May 2020 15:45:26 -0400 From: Tom Lane To: Robert Haas cc: Fujii Masao , Tomas Vondra , Alvaro Herrera , Masahiko Sawada , "tsunakawa.takay@fujitsu.com" , "pgsql-hackers@postgresql.org" Subject: Re: SLRU statistics In-reply-to: References: <20200229205518.xrxo535zgd7cl6no@development> <20200327004111.md4suoi6u5suv2qe@development> <20200328002630.2nz5y3dvymqnvxtv@development> <20200402004136.wodwftan45mcwggm@development> <20200430181901.24tlriahmafi4sfn@development> <0e1c8904-13be-ab70-0096-54f0b30e43ba@oss.nttdata.com> <20200502000818.nn4kpewiput42bnb@development> <49b8ad17-f6d9-a086-a952-ff1fec3ac1b3@oss.nttdata.com> <20200502105500.hwhba3d6s3hlrqf6@development> <20200502165905.brfxv6dk5vjdbgti@development> <976bbb73-a112-de3c-c488-b34b64609793@oss.nttdata.com> Comments: In-reply-to Robert Haas message dated "Thu, 14 May 2020 14:52:06 -0400" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <13486.1589485526.1@sss.pgh.pa.us> Date: Thu, 14 May 2020 15:45:26 -0400 Message-ID: <13487.1589485526@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Robert Haas writes: > I'm confused by why SLRU statistics are reported by messages sent to > the stats collector rather than by just directly updating shared > memory. It would be better to consider that as an aspect of the WIP stats collector redesign, rather than inventing a bespoke mechanism for SLRU stats that's outside the stats collector (and, no doubt, would have its own set of bugs). We don't need to invent even more pathways for this sort of data. regards, tom lane