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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: Negative value of numGroups
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 <ed1d1a2d-6061-24e5-e8eb-dbda3ec8f66c@postgrespro.ru>
Comments: In-reply-to Andrey Lepikhov <a.lepikhov@postgrespro.ru>
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Andrey Lepikhov <a.lepikhov@postgrespro.ru> writes:
> On 13/5/2022 11:56, Andrey Lepikhov wrote:
>> (long) Min(numGroups, (double) LONG_MAX);
>> 
>> can return negative value, if numGroups > LONG_MAX.

I see your point, but I don't think that repeating the same finicky
and undocumented coding pattern in multiple places is a future-proof
fix.  I'm inclined to think we should invent a function along the
lines of "long clamp_double_to_long(double x)".  Given where it's
used, maybe putting it beside clamp_row_est() would be good.

			regards, tom lane