From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>,
        Matthias van de Meent <boekewurm+postgres@gmail.com>,
        Andrei Lepikhov <lepihov@gmail.com>,
        pgsql-hackers@lists.postgresql.org,
        Guillaume Lelarge <guillaume@lelarge.info>,
        Matheus Alcantara <matheusssilv97@gmail.com>,
        Alena Rybakina <a.rybakina@postgrespro.ru>
Subject: Re: explain analyze rows=%.0f
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Mon, 31 Mar 2025 13:35:49 -0400"
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Date: Mon, 31 Mar 2025 13:49:55 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> But why isn't it just as valuable to have two decimal places for the
> estimate? I theorize that the cases that are really a problem here are
> those where the row count estimate is between 0 and 1 per row, and
> rounding to an integer loses all precision.

Currently, the planner rounds *all* rowcount estimates to integers
(cf. clamp_row_est()).  Maybe it'd be appropriate to rethink that,
but it's not just a matter of changing EXPLAIN's print format.

			regards, tom lane