Re: get_actual_variable_range vs idx_scan/idx_tup_fetch, again

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Marko Tiikkaja <marko@joh.to>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-03-05T15:08:57Z
Lists: pgsql-hackers
Marko Tiikkaja <marko@joh.to> writes:
> So I'm in the same pickle again.  According to pg_stat_user_indexes an
> index is being used all the time.  However, it's only being used by
> mergejoinscansel() to compare these two plans:

If it's not being used otherwise, could you drop it?

> I think it would be really important to have a way to turn off
> get_actual_variable_range() for a specific index during runtime.  Would a C
> level hook be acceptable for this?

You haven't really made a case for why you (or anyone else) should care.
As long as the planner makes the right choice, having investigated a wrong
choice doesn't seem like a bug to me.

			regards, tom lane