On Monday 21 November 2005 20:04, Michael Glaesemann wrote:
> On Nov 22, 2005, at 3:19 , Dennis Veatch wrote:
> > I had thought just adding some fields called topsoil_start/
> > topsoil_end,
> > gravel_start/gravel_end, etc. But them I'm left with how to take
> > those values
> > and give to total depth for each layer and total depth of the well.
> >
> > But I'm not sure that is the best way to handle this.
> >
> > Does anyone have some other suggestions?
>
> This is similar in concept to temporal intervals. You might want to
> look at "Temporal Data and the Relational Model" by Date, Darwen, and
> Lorentzos for general theory, and "Developing Time-Oriented Database
> Applications" by Richard Snodgrass for implementations in SQL. The
> latter is available as a PDF download (the book itself is out of print):
> http://www.cs.arizona.edu/people/rts/tdbbook.pdf
>
> Hope this helps!
>
Hee, well that's um, kinda over my head. Hee and I'm not all the way through
the PostgreSQL book I just bought. There's probably a gap there. :)
Though I will try to glean something out of the link.
--
You can tuna piano but you can't tune a fish.
