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.
