Re: Can we use Statistics Import and Export feature to perforamance testing?

Corey Huinker <corey.huinker@gmail.com>

From: Corey Huinker <corey.huinker@gmail.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: "Ryohei Takahashi (Fujitsu)" <r.takahashi_2@fujitsu.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2025-04-12T08:29:42Z
Lists: pgsql-hackers
>
> at the *actual size* of the relation and takes that into account when
> scaling the statistics (see table_block_relation_estimate_size() in
> tableam.c). If the table sizes don't match between the two servers
> then there's no guarantees the planner will produce the same plan.
>

Sorry that I didn't see this thread until now. I would like to note that
table_block_relation_estimate_size() determines the actual size of the
relation by asking pg_class, and the relevant values there are set by
pg_restore_relation_stats().