Message-ID: <c9f91659-f17d-41f4-ad16-2801cf61b608@gmail.com>
Date: Wed, 19 Feb 2025 16:37:40 +0100
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Subject: Re: explain analyze rows=%.0f
To: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>,
 Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>,
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 Daniel Gustafsson <daniel@yesql.se>, Ibrar Ahmed <ibrar.ahmad@gmail.com>,
 "Gregory Stark (as CFM)" <stark.cfm@gmail.com>,
 Amit Kapila <amit.kapila16@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>,
 Peter Geoghegan <pg@bowt.ie>, vignesh C <vignesh21@gmail.com>,
 "David G. Johnston" <david.g.johnston@gmail.com>,
 Alena Rybakina <a.rybakina@postgrespro.ru>
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From: Andrei Lepikhov <lepihov@gmail.com>
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On 19/2/2025 15:01, Ilia Evdokimov wrote:
> If we want to convey this information more clearly, we should consider a 
> more explicit approach. For example, instead of using a fractional 
> value, we could display the minimum and maximum row counts observed 
> during execution (e.g.,rows=10..20, formatting details could be 
> discussed). However, in my opinion, this discussion is beyond the scope 
> of this thread.
I think this approach is redundant. Usually, a problem is an unknown 
number of tuples because, having millions of loops, we produce a small 
number of tuples, but each tuple costs a lot because of a subplan or 
something like that. By printing fractional digits (of course, we need 
to view significant ones, but we already agreed on a couple of digits 
for now), we may resolve this corner-case problem fully - at least all 
examples in my experience would be resolved, and I have even maintained 
a patch for years to manage this.
Moreover, it is too simple to implement. I just can't imagine why not to 
do it right now.

-- 
regards, Andrei Lepikhov