Re: Floating point comparison inconsistencies of the geometric types

Hello,

At Thu, 29 Sep 2016 10:37:30 +0200, Emre Hasegeli <emre@hasegeli.com> wrote in
<CAE2gYzxijWKwJ-ZPD--QHM+SxMd+vL_81_3Xt0spnCbsqFH=Ug@mail.gmail.com>
> > regression=# select 'I- 580                        Ramp' < 'I- 580/I-680                  Ramp';
> >  ?column?
> > ----------
> >  t
> > (1 row)
> 
> on the Linux server I am testing, it is not:
> 
> > regression=# select 'I- 580                        Ramp' < 'I- 580/I-680                  Ramp';
> >  ?column?
> > ----------
> >  f
> > (1 row)
> 
> The later should be the case on your environment as the test was also
> failing for you.  This is not consistent with the expected test
> result.  Do you know how this test can still pass on the master?

Perhaps you ran the test under the environment LC_COLLATE (or
LANG) of something other than C. The reson for the result is
collation. The following returns expected result.


=# select 'I- 580                        Ramp' < ('I- 580/I-680                  Ramp' COLLATE "C");?column? 
----------t
(1 row)

For a reason I don't know, say, en_US locale behaves in an
unintuitive way.

regression=# select ' ' < ('/' COLLATE "en_US"), ' x' < ('/a' COLLATE "en_US");?column? | ?column? 
----------+----------t        | f
(1 row)


Returning to the issue, the following query should give you the
expected result.

SELECT name, #thepath  FROM iexit ORDER BY name COLLATE "C", 2;

regards,

-- 
Kyotaro Horiguchi
NTT Open Source Software Center