Re: Negative value of numGroups - Mailing list pgsql-bugs

From Tom Lane
Subject Re: Negative value of numGroups
Date
Msg-id 1584431.1652801657@sss.pgh.pa.us
Whole thread Raw
In response to Re: Negative value of numGroups  (Andrey Lepikhov <a.lepikhov@postgrespro.ru>)
Responses Re: Negative value of numGroups
List pgsql-bugs
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



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