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

From: Corey Huinker <corey(dot)huinker(at)gmail(dot)com>
To: David Rowley <dgrowleyml(at)gmail(dot)com>
Cc: "Ryohei Takahashi (Fujitsu)" <r(dot)takahashi_2(at)fujitsu(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Can we use Statistics Import and Export feature to perforamance testing?
Date: 2025-04-12 08:29:42
Message-ID: CADkLM=fV95NKw4x9pBtaXHtQP4=21nmjDBuv2XJm3ZiNgc0AKw@mail.gmail.com
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>
> 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().

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