Re: Temporal database - no end date
Date: Mon, 22 Jan 2007 05:30:14 GMT
Message-ID: <GZXsh.3929$1x.66119_at_ursa-nb00s0.nbnet.nb.ca>
JOG wrote:
> PMFJI as I have no knowledge of this area, and am just trying to
> interpret the points being made.
>
> I just wanted to clarify the example being given: Children can only be
> counted, and hence number of children is represented by an Integer.
> Division operating with closure over the set of integers will clearly
> not reveal useful fertility statistics. However a division operation
> over integers does not /have to/ exhibit closure. Can the same not be
> said for working with chronons? Is it being stated that the DDL model
> requires that all operations on chronon's must exhibit closure? Or am I
> missing something more subtle.
Intervals are sets of points in time. That doesn't prevent people from calculating the duration between two of those points in time. That doesn't prevent people from calculating average durations. Intervals themselves are not durations. That is all.
Someone is making a tempest in a teacup. Received on Mon Jan 22 2007 - 06:30:14 CET