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 1jsJhD-0007FL-2x for pgsql-hackers@arkaria.postgresql.org; Mon, 06 Jul 2020 05:29:39 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1jsJhB-00033r-WA for pgsql-hackers@arkaria.postgresql.org; Mon, 06 Jul 2020 05:29:38 +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 1jsJhB-00033k-Oj for pgsql-hackers@lists.postgresql.org; Mon, 06 Jul 2020 05:29:37 +0000 Received: from oss.nttdata.com ([49.212.34.109]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jsJh8-0002Vc-I5 for pgsql-hackers@postgresql.org; Mon, 06 Jul 2020 05:29:37 +0000 Received: from hnk.local (p2604028-ipngn12401funabasi.chiba.ocn.ne.jp [180.1.110.28]) by oss.nttdata.com (Postfix) with ESMTPSA id F2C426056A; Mon, 6 Jul 2020 14:29:28 +0900 (JST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.102.3 at oss.nttdata.com Subject: Re: track_planning causing performance regression To: Pavel Stehule Cc: Peter Geoghegan , Julien Rouhaud , "Tharakan, Robins" , "pgsql-hackers@postgresql.org" References: <2895b53b033c47ccb22972b589050dd9@EX13D05UWC001.ant.amazon.com> <42a13b4c-e60c-c6e7-3475-8eff8050bed4@oss.nttdata.com> <646e5cae-5e8b-feaa-43dc-014bf355bf08@oss.nttdata.com> <73b66e99-b4f3-9c4e-3b70-157ddbe81771@oss.nttdata.com> From: Fujii Masao Message-ID: Date: Mon, 6 Jul 2020 14:29:28 +0900 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 2020/07/04 12:22, Pavel Stehule wrote: > > > pá 3. 7. 2020 v 13:02 odesílatel Fujii Masao > napsal: > > > > On 2020/07/03 16:02, Pavel Stehule wrote: > > > > > > pá 3. 7. 2020 v 8:57 odesílatel Fujii Masao >> napsal: > > > > > > > >     On 2020/07/03 13:05, Pavel Stehule wrote: > >      > Hi > >      > > >      > pá 3. 7. 2020 v 4:39 odesílatel Fujii Masao > >>> napsal: > >      > > >      > > >      > > >      >     On 2020/07/01 7:37, Peter Geoghegan wrote: > >      >      > On Tue, Jun 30, 2020 at 6:40 AM Fujii Masao > >>> wrote: > >      >      >> Ants and Andres suggested to replace the spinlock used in pgss_store() with > >      >      >> LWLock. I agreed with them and posted the POC patch doing that. But I think > >      >      >> the patch is an item for v14. The patch may address the reported performance > >      >      >> issue, but may cause other performance issues in other workloads. We would > >      >      >> need to measure how the patch affects the performance in various workloads. > >      >      >> It seems too late to do that at this stage of v13. Thought? > >      >      > > >      >      > I agree that it's too late for v13. > >      > > >      >     Thanks for the comment! > >      > > >      >     So I pushed the patch and changed default of track_planning to off. > >      > > >      > > >      > Maybe there can be documented so enabling this option can have a negative impact on performance. > > > >     Yes. What about adding either of the followings into the doc? > > > >           Enabling this parameter may incur a noticeable performance penalty. > > > >     or > > > >           Enabling this parameter may incur a noticeable performance penalty, > >           especially when a fewer kinds of queries are executed on many > >           concurrent connections. > > > > > > This second variant looks perfect for this case. > > Ok, so patch attached. > > > +1 Thanks for the review! Pushed. Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION