Re: object algebra
Date: 26 Feb 2004 22:06:51 -0800
Message-ID: <4b45d3ad.0402262206.63da1fc4_at_posting.google.com>
> RDM doesn't create a null. Only an incorrect database design does. The model
> has nothing to do with it, unless by "model" you're referring to your
> specific database design.
Date's Intro to Dbs, 6th Ed, pg 570, 1st paragrah of Chapter 20 - Missing Info: "the problem of missing information is one that is encountered very frequently in the real world", "are too common in real-world situations and so it is necessary to have some way of dealing with such situations in our formal database system". Chapter Summary: "3VL suffers from the very serious ("showstopper") problem that it does not match reality, that is results that are correct according to 3VL are sometimes incorrect in the real world".
> RDM as a general model is fine.
In the overall scope of things, it is currently the best. Received on Fri Feb 27 2004 - 07:06:51 CET