Re: Re: BUG #12885: The result of casting a double to an integer depends on the database version

On Thu, Mar 26, 2015 at 9:19 AM, Andrew Gierth
<andrew(at)tao11(dot)riddles(dot)org(dot)uk> wrote:
>>>>>> "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>
> Tom> BTW, if memory serves we also have a pretty lazy rounding
> Tom> implementation for the numeric datatype. I wonder if now would be
> Tom> a good time to upgrade that to be round-to-nearest-even as well.
>
> A data point: there have been occasional complaints on IRC about the
> fact that numeric rounding is not round-to-even, but obviously it's
> harder to tell if anyone is relying on the current behavior.

Indeed...
=# select column1 AS double_value, cast(column1 AS INT) AS int_value
FROM (VALUES (-2.5::numeric),
(-1.5::numeric),
(-0.5::numeric),
(0.5::numeric),
(1.5::numeric),
(2.5::numeric)) t;
double_value | int_value
--------------+-----------
-2.5 | -3
-1.5 | -2
-0.5 | -1
0.5 | 1
1.5 | 2
2.5 | 3
(6 rows)

Tom, if there is a patch showing up soon, would you integrate it? I
imagine that it would be good to have the same behavior for a maximum
of datatypes in 9.5 now that src/port/rint.c is more compliant.
Regards,
--
Michael