Horton

Re: strange slow query - lost lot of time somewhere

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: David Rowley <dgrowleyml@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-05-03T05:02:09Z
Lists: pgsql-hackers 
út 3. 5. 2022 v 6:57 odesílatel Tom Lane <tgl@sss.pgh.pa.us> napsal:

> Pavel Stehule <pavel.stehule@gmail.com> writes:
> > there is really something strange (see attached file). Looks so this
> issue
> > is much more related to planning time than execution time
>
> You sure there's not something taking an exclusive lock on one of these
> tables every so often?
>

I am almost sure, I can see this issue only every time when I set a higher
work mem. I don't see this issue in other cases.

Regards

Pavel



>
>                         regards, tom lane
>

Commits

  1. Correct Memoize's estimated cache hit ratio calculation

  2. Fix incorrect row estimates used for Memoize costing

  3. Allow Memoize to operate in binary comparison mode