Horton

Re: track_planning causing performance regression

Justin Pryzby <pryzby@telsasoft.com>

View thread View on postgr.es
From: Justin Pryzby <pryzby@telsasoft.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
Date: 2021-04-18T23:36:15Z
Lists: pgsql-hackers 
Reviewing this change which was committed last year as
321fa6a4a26c9b649a0fbec9fc8b019f19e62289

On Fri, Jul 03, 2020 at 03:57:38PM +0900, Fujii Masao wrote:
> On 2020/07/03 13:05, Pavel Stehule wrote:
> > pá 3. 7. 2020 v 4:39 odesílatel Fujii Masao <masao.fujii@oss.nttdata.com> napsal:
> > 
> > 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.

Something seems is wrong with this sentence, and I'm not sure what it's trying
to say.  Is this right ?

>     Enabling this parameter may incur a noticeable performance penalty,
>     especially when a small number of queries are executed on many
>     concurrent connections.

-- 
Justin

Commits

  1. doc: Fix description about pg_stat_statements.track_planning.

  2. doc: Add note about possible performance overhead by enabling track_planning.

  3. Change default of pg_stat_statements.track_planning to off.