Re: track_planning causing performance regression
Hamid Akhtar <hamid.akhtar@gmail.com>
From: Hamid Akhtar <hamid.akhtar@gmail.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, Peter Geoghegan <pg@bowt.ie>, Julien Rouhaud <rjuju123@gmail.com>, "Tharakan, Robins" <tharar@amazon.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-07-31T12:40:34Z
Lists: pgsql-hackers
<https://commitfest.postgresql.org/29/2634/> On Mon, Jul 6, 2020 at 10:29 AM Fujii Masao <masao.fujii@oss.nttdata.com> wrote: > > > On 2020/07/04 12:22, Pavel Stehule wrote: > > > > > > pá 3. 7. 2020 v 13:02 odesílatel Fujii Masao < > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>> napsal: > > > > > > > > On 2020/07/03 16:02, Pavel Stehule wrote: > > > > > > > > > pá 3. 7. 2020 v 8:57 odesílatel Fujii Masao < > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>>> napsal: > > > > > > > > > > > > On 2020/07/03 13:05, Pavel Stehule wrote: > > > > Hi > > > > > > > > pá 3. 7. 2020 v 4:39 odesílatel Fujii Masao < > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>>>> > napsal: > > > > > > > > > > > > > > > > On 2020/07/01 7:37, Peter Geoghegan wrote: > > > > > On Tue, Jun 30, 2020 at 6:40 AM Fujii Masao < > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com> <mailto: > masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>>>> 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/ -- Highgo Software (Canada/China/Pakistan) URL : www.highgo.ca ADDR: 10318 WHALLEY BLVD, Surrey, BC CELL:+923335449950 EMAIL: mailto:hamid.akhtar@highgo.ca SKYPE: engineeredvirus
Commits
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doc: Fix description about pg_stat_statements.track_planning.
- 306c5e05e20f 13.4 landed
- e48f2afee631 14.0 landed
- 9d2a7757347c 15.0 landed
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doc: Add note about possible performance overhead by enabling track_planning.
- da6b6ff95bca 13.0 landed
- 321fa6a4a26c 14.0 landed
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Change default of pg_stat_statements.track_planning to off.
- 8d459762b103 13.0 landed
- d1763ea8c9c3 14.0 landed