Re: Range type adaptation implemented

On Mon, Sep 24, 2012 at 10:45 AM, Karsten Hilbert
<Karsten.Hilbert@gmx.net> wrote:

On Mon, Sep 24, 2012 at 09:56:14AM +0100, Daniele Varrazzo wrote:

The funniest surprise I've had during the development

was an error creating the object TextRange('#', '$') in the database.

It should be possible as

ord('#'), ord('$')

   (35, 36)

but PG insisted that "range lower bound must be less than or equal to

range upper bound". Well, turns out that:

   postgres=# select ascii('#') < ascii('$'), '#' < '$';

    ?column? | ?column?

   ----------+----------

    t        | f

   (1 row)

This does not seem intuitive but is probably quite logical:

While

       ascii('#') < ascii('$')

eventually compares numerical values (35 and 36) the comparison

       '#' < '$'

operates on characters the sorting order (<) of which

depends on the lcoale in use.

That's right: the reason is the locale. select '#' collate "C" < '$'
collate "C" returns true as naively expected.

-- Daniele