On Wed, Jan 20, 2021 at 9:12 PM tsunakawa.ta...@fujitsu.com
<tsunakawa.ta...@fujitsu.com> wrote:
> This behavior may possibly be considered as an intended behavior for the
> reason that Update/Insert/Delete nodes don't output rows without RETURNING.
> Is this a bug or a correct behavior?
Hi Tsunakawa-san,
This was a change made deliberately. Do you see a problem?
commit f0f13a3a08b2757997410f3a1c38bdc22973c525
Author: Thomas Munro <tmu...@postgresql.org>
Date: Mon Oct 12 20:41:16 2020 +1300
Fix estimates for ModifyTable paths without RETURNING.
In the past, we always estimated that a ModifyTable node would emit the
same number of rows as its subpaths. Without a RETURNING clause, the
correct estimate is zero. Fix, in preparation for a proposed parallel
write patch that is sensitive to that number.
A remaining problem is that for RETURNING queries, the estimated width
is based on subpath output rather than the RETURNING tlist.
Reviewed-by: Greg Nancarrow <gregn4...@gmail.com>
Discussion: https://postgr.es/m/CAJcOf-cXnB5cnMKqWEp2E2z7Mvcd04iLVmV%3DqpFJr
R3AcrTS3g%40mail.gmail.com
