Data Display & Modeling

From: Dawn M. Wolthuis <dwolt_at_tincat-group.com>
Date: Thu, 6 May 2004 14:26:43 -0500
Message-ID: <c7e3hr$t0c$1_at_news.netins.net>

Let's say that someone likes to model data as functions [e.g. PERSON(key)=tuple ], in non-1NF and in di-graphs (so you can navigate your way through it), with a target implementation in XML or PICK. I have heard people say that is a good way to "view" the data, but we need to model it using relational theory.

Given:

1. that there is a good non-relational way to view the data, such as one using di-graphs with functions on strings.
2. that relational theory provides us with a loss-less decomposition of the data.
3. that we can mark-up the di-graph with information to permit automatic normalization of the data, so that we could switch between these two "pictures" of the data (O-R mappings, for example)

Then, these two models are just two pictures of the same data and one could pop back and forth between them.

Then the software/database developer could view the data model either way, and, therefore, never have to bother with relational notation at all.

4. Now figure that relational theory is not related to the physical storage of the data.

Then there is no reason to even add the notations to switch between the di-graph and relational provided that everything the system needs to store the data is provided in the di-graph "picture" -- there just needs to be a mapping between the di-graph and the physical model, which can be optimized for machine processes (therfore, likely NOT relational!)

Therefore, I see no reason for that R part in any aspect of the system, other than (recent) tradition and the fact that a ton of data has been (unnecessarily) placed in 1NF. If the application of relational processes were really loss-less, then the data could be viewed the way I like to see it (but, alas, while non-1NF databases have no problem showing themselves as if they were relational, the reverse is often not the case).

I'd like to see diagramming tools for data modeling to specify data in its more conceptually simple format of propositions as functions that need not be in 1NF, showing foreign key links and such -- a web of data.

I have an appreciation for the relational model set theory and I think 2nd, 3rd, and 5th normal forms are useful (when not defined in terms of 1NF), but I have very little use for the relational model outside of that -- certainly not for any human to and from computer nor computer to computer communication purposes. And my appreciation for SQL is almost completely related to the fact that it has given us some industry standards that are used extensively. It is a language begging for retirement.

I'm not sure that there will always be a need for the "R" in O-R mappings and that would certainly save both human and computer processing cycles. You can figure I'm just ignorant (if that helps you in some way), but I have not yet SEEN enough of what the R gives the IT profession to justify it and it sure has cost us a bunch.
--dawn Received on Thu May 06 2004 - 21:26:43 CEST