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 1k7bKv-0003Ji-Io for pgsql-hackers@arkaria.postgresql.org; Mon, 17 Aug 2020 09:21:49 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1k7bKu-00020R-Gw for pgsql-hackers@arkaria.postgresql.org; Mon, 17 Aug 2020 09:21:48 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k7bKu-00020A-AC for pgsql-hackers@lists.postgresql.org; Mon, 17 Aug 2020 09:21:48 +0000 Received: from oss.nttdata.com ([49.212.34.109]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1k7bKr-0003g0-5z for pgsql-hackers@postgresql.org; Mon, 17 Aug 2020 09:21:47 +0000 Received: from hnk.local (p12054-ipngn2901funabasi.chiba.ocn.ne.jp [153.212.171.54]) by oss.nttdata.com (Postfix) with ESMTPSA id 16DA4600F7; Mon, 17 Aug 2020 18:21:42 +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: Hamid Akhtar Cc: Pavel Stehule , 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: <773565c1-6508-063a-8872-20c16d283ee8@oss.nttdata.com> Date: Mon, 17 Aug 2020 18:21:41 +0900 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 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 2020/07/31 21:40, Hamid Akhtar wrote: > > > On Mon, Jul 6, 2020 at 10:29 AM Fujii Masao > wrote: > > > > 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 > > > > You might also want to update this patch's status in the commitfest: > https://commitfest.postgresql.org/29/2634/ The patch added into this CF entry has not been committed yet. So I was thinking that there is no need to update the status yet. No? Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION