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>> 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>> 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.
Thank you
Pavel
Regards,
-- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION