Re: Scaled or Granular Dates

From: Jonathan Leffler <jleffler_at_earthlink.net>
Date: Fri, 09 Jan 2004 00:16:53 GMT
Message-ID: <VpmLb.816$Pg.670@newsread1.news.pas.earthlink.net>

--CELKO-- wrote:

>>>January 2004 Scientific American?  It is mind blowing.  It might

> also be wrong. The preamble reads 'We perceive space and time to be
> continuous, but if the amazing theory of loop quantum gravity is
> correct, they actually come in discrete pieces'. ... but maybe the
> sweeping statement about continuity of time is overstated. <<
>
> That is on the stack for the month. I am swamped right now; one of
> the many problems with being a grown up is that you have to provide
> Christmas instead of enjoy it.

I know that feeling :-)

> Actually, Wolfram is into a fully
> discrete model of the universe-as-finite-automata that is interesting.

Deus ex machina? Stochastic, and even if finite, the automata would have to be awfully big. I think we're off at a tangent here, though :-)

>>>There's also a book "Time Granularities in Databases, Data Mining,

> and Temporal Reasoning" by C Bettini, S Jajodia, S X Wang, published
> by Springer, 2000, ISBN 3-540-66997-3 (in Engish, despite the ISBN
> prefix suggesting German). I've not read it all yet - on the to do
> list - but it might be of some relevance, too. <<
>
> Sounds good; I'll take a look. Do you have the Morgan-Kaufmann book
> by Rick Snodgrass? Lots of code, but you can go back to his work at
> University of Arizona for the theoretical stuff.

Yes, I have "Developing Time-Oriented Database Applications in SQL" by Snodgrass. Its both harder and simpler than Time Granularities. Harder because it is messing with real-world SQL and the mess that different DBMS vendors provide for supporting, more or less, temporarl data. Easier because it isn't so deeply into the meaning of 'granularities'. Still, DTODA is well worth a look because it is much easier to read than TG (but Amazon says it is currently not available, whereas TG is still available).

The original question was definitely related to granularities - though that may have been lost given that both of us have dropped all the original question from the messages.

-- 
Jonathan Leffler                   #include <disclaimer.h>
Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com
Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/

Received on Thu Jan 08 2004 - 18:16:53 CST