Re: Range Types - symmetric

Jeff Davis wrote:
> On Tue, 2011-09-13 at 12:34 -0400, Christopher Browne wrote:
> > > select int4range(5,2);
> > > ERROR:  range lower bound must be less than or equal to range upper bound
> > >
> > > Of course, I won't argue this is a bug, but I was wondering if it wouldn't be handy to allow a
> > > 'symmetric' mode in range construction, where, if the first of the pair is higher than the second,
> > > they are automatically swapped, similar to SYMMETRIC in the BETWEEN clause.
> 
> ...
> 
> > If you have a computation that gets a "backwards" range, then it is
> > more than possible that what you've got isn't an error of getting the
> > range backwards, but rather the error that your data is
> > overconstraining, and that you don't actually have a legitimate range.
> 
> Agreed. On balance, it's just as likely that you miss an error as save a
> few keystrokes.
> 
> I'll add that it would also cause a little confusion with inclusivity.
> What if you do: '[5,2)'::int4range? Is that really '[2,5)' or '(2,5]'?

Reminder:  BETWEEEN supports the SYMMETRIC keyword, so there is
a precedent for this.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +