Re: Bug and/or feature? Complex data types in tables...

On Thu, Jan 15, 2004 at 08:29:41PM +0900, Michael Glaesemann wrote:

> >Is there a problem with the built in definitions of point and interval?
>
> I'm thinking along the lines of the temporal proposals Date, Darwen,
> and Lorentzos ("Temporal Data and the Relational Model"). Their
> "interval" type is more along the lines of a beginning and end time,
> such as ['2003-1-23':'2003-1-25'], rather than just '2 days'.

Maybe it's tangential to this discussion, but there's a type to store
that kind of intervals.  It's called tinterval.  ISTM it's not too much
documented, and I haven't really used it.

alvherre=> select tinterval('2003-10-28', '2004-11-05');
                      tinterval
-----------------------------------------------------
 ["2003-10-28 00:00:00-03" "2004-11-05 00:00:00-03"]
(1 fila)

alvherre=> select tinterval('2003-10-28', '2004-11-05') && tinterval('2003-10-05', '2003-10-15');
 ?column?
----------
 f
(1 fila)

alvherre=> select tinterval('2003-10-28', '2004-11-05') && tinterval('2003-10-05', '2003-11-15');
 ?column?
----------
 t
(1 fila)

(There are other operators, of course ...)

--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
Criptografía: Poderosa técnica algorítmica de codificación que es
empleada en la creación de manuales de computadores.