Horton

Re: Is it useful to record whether plans are generic or custom?

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: torikoshia@oss.nttdata.com
Cc: pgsql-hackers@postgresql.org, masao.fujii@oss.nttdata.com, tatsuro.yamada.tf@nttcom.co.jp, pavel.stehule@gmail.com, legrand_legrand@hotmail.com
Date: 2021-01-25T05:10:20Z
Lists: pgsql-hackers 
At Tue, 12 Jan 2021 20:36:58 +0900, torikoshia <torikoshia@oss.nttdata.com> wrote in 
> I suppose it would be normal practice to store past results of
> pg_stat_statements for future comparisons.
> If this is the case, I think that if we only add the number of
> generic plan execution, it will give us a hint to notice the cause
> of performance degradation due to changes in the plan between
> generic and custom.

Agreed.

> Attached a patch that just adds a generic call counter to
> pg_stat_statements.
> 
> Any thoughts?

Note that ActivePortal is the closest nested portal. So it gives the
wrong result for nested portals.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Add generic_plans and custom_plans fields into pg_prepared_statements.