On Jun 23, 2006, at 9:47 , Michael Glaesemann wrote:
> # select '41 mon'::interval / 10;
> ?column?
> ------------------------
> 4 mons 2 days 24:00:00
> My understanding is that as month_remainder is a float (as is
> month_remainder_days), month_remainder_days may be equal to 24
> hours after rounding. As we're converting from months to days, and
> from days to time, rather than from months to time directly, we're
> assuming that we should only have time less than 24 hours remaining
> in the month_remainder_days when it's added to day_remainder.
This behavior is the same as applying justify_hours before adding the
days and time components to the result. With this in mind, I rewrote
interval_div to call interval_justify_hours. Good news is that --
enable-integer-datetimes works as expected. Bad news is that without
--enable-integer-datetimes, still get the current behavior.
I also came across something I think is odd:
# select version();
version
------------------------------------------------------------------------
----------------------------------------------------------------------
PostgreSQL 8.1.4 on powerpc-apple-darwin8.7.0, compiled by GCC
powerpc-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc.
build 5341)
(1 row)
select justify_hours(a/10) as divided_and_justified , justify_hours(b) as justified , a/10 = b as are_equal
from (select '41 mon'::interval,'4 mons 2 days 24:00:00'::interval)
as s(a,b);
without --enable-integer-datetimes:
divided_and_justified | justified | are_equal
------------------------+---------------+-----------
4 mons 2 days 24:00:00 | 4 mons 3 days | t
(1 row)
with --enable-integer-datetimes:
divided_and_justified | justified | are_equal
-----------------------+---------------+-----------
4 mons 3 days | 4 mons 3 days | t
I think this just confirms that there is some kind of rounding (or
lack of) in interval_div. Kind of frustrating that it's not visible
in the result.
Anyway, there's another data point.
Michael Glaesemann
grzm seespotcode net
