RE: power() function in Windows: "value out of range: underflow"

Hi,
Thanks for response

# I will add this thread to current CF soon.

> 2018-04-10 5:30 GMT-03:00 Huong Dangminh <huo-dangminh(at)ys(dot)jp(dot)nec(dot)com>:
> > There are some cases that power() function does not work correctly
> > with 'NaN' arguments in Windows environment.
> > Something like,
> >
> What is your exact OS version? What is your postgres version? I tested with
> Windows 10 (10.0.16299) x64 and couldn't reproduce the error.

I think it is not depended on OS version but the visual c++ runtime libraries version
(It seem also be included in installers).

My environment:
====================================

- PostgreSQL: 9.6.8
# I am using the EDB PostgreSQL Installer
# It also can reproduce in PostgreSQL 10.3 or 9.5.12

>postgres -V
postgres (PostgreSQL) 9.6.8

>psql -c "select version()"
version
-------------------------------------------------------------
PostgreSQL 9.6.8, compiled by Visual C++ build 1800, 64-bit
(1 row)

>psql -c "select 'NaN'^11"
ERROR: value out of range: underflow

- OS: Microsoft Windows 10 Pro 10.0.14393 build 14393

=============================

> > postgres=# select power('NaN',11);
> > ERROR: value out of range: underflow
> > postgres=# select power('NaN','NaN');
> > ERROR: value out of range: underflow
> > postgres=# select power(11,'NaN');
> > ERROR: value out of range: underflow
> >
> > In Linux environment, instead of ERROR it returns 'NaN'.
> >
> Could you show us a simple test case? Print arguments, result and errno.

It just is my confirmation when debug PostgreSQL in Windows environment.
# I built PostgreSQL with VC++ 2012 in debug mode and confirmed.
I don't know how to print those values.

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Thanks and best regards,
Dang Minh Huong
NEC Solution Innovators, Ltd.
http://www.nec-solutioninnovators.co.jp/en/