Re: [PoC] Reducing planning time when tables have many partitions

Hi Andrey,

On Tue, Aug 8, 2023 at 8:52 AM Andrey Lepikhov
<a(dot)lepikhov(at)postgrespro(dot)ru> wrote:
> It is a positive thing to access some planner internals from the
> console, of course. My point is dedicated to the structuration of an
> EXPLAIN output and is caused by two reasons:
> 1. I use the EXPLAIN command daily to identify performance issues and
> the optimiser's weak points. According to the experience, when you have
> an 'explain analyze' containing more than 100 strings, you try removing
> unnecessary information to improve observability. It would be better to
> have the possibility to see an EXPLAIN with different levels of the
> output details. Flexibility here reduces a lot of manual work, sometimes.

I use the json output format to extract the interesting parts of
EXPLAIN output. See my SQL scripts attached upthread. That way I can
ignore new additions like this.

> 2. Writing extensions and having an explain analyze in the regression
> test, we must create masking functions just to make the test more
> stable. That additional work can be avoided with another option, like
> MEMUSAGE ON/OFF.

We already have a masking function in-place. See changes to
explain.out in my proposed patch at [1]

> > I will propose it as a separate patch in the next commitfest and will
> > seek opinions from other hackers.
> Cool, good news.

Done. Commitfest entry https://commitfest.postgresql.org/44/4492/

[1] https://www.postgresql.org/message-id/CAExHW5sZA=5LJ_ZPpRO-w09ck8z9p7eaYAqq3Ks9GDfhrxeWBw@mail.gmail.com

--
Best Wishes,
Ashutosh Bapat