On 5/28/05, Tom Lane wrote:
>
> I think they may have intended to treat each time interval
> as the half-open interval [S,T), that is S <= time < T. However
> that would leave a zero-length interval as completely empty and
> thereby arguably not overlapping anything ... which they didn't
> make it do.
IIRC Jim Melton wrote in one of his books (SQL:1999 or Advanced
SQL:1999, I don't remember) that the intention was to allow easy diary
type comparisons. If you have 2 appointments both with a start and an
end date of 2005-06-09, they overlap. If you have appointments from
08:00 to 10:00 and from 10:00 to 12:00 on that same day, they don't
overlap.
Jochem
---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?
http://archives.postgresql.org
