Re: Impossible Database Design?

"Jay Dee" <ais01479_at_aeneas.net> wrote in message news:ehubg.35069$mh.17481_at_tornado.ohiordc.rr.com...
> -CELKO- wrote:

> Regarding domains: the question, "Is absorption a property of some value
> in the domain?" must be answered depending on what the domain is and how
> it can reasonably be represented. If, as someone else said in this
> thread, "all time intervals have a starting point but they may not
> always end" (Or something to that effect. Seems strange to me, but...)
> one may want to use something they call NULL to represent the end of
> time which will never occur. Then, next(NULL) = NULL and infinity has
> been represented. The question, "What does previous(NULL) give me?" is
> up to the domain modeler. If he thinks he can put a date/time stamp
> on the instant before a time which will never come: go for it!

next(a)=NULL
next(NULL)=NULL
previous(NULL)={a,NULL}
next({a,NULL})={NULL,NULL}
previous({NULL,NULL})= ?

I liked that episode from Futurama in which Fry visited the edge of the universe. Received on Mon May 22 2006 - 13:51:12 CEST