Re: Multi Valued Interface Models?

From: JOG <jog_at_cs.nott.ac.uk>
Date: 13 Feb 2006 19:52:30 -0800
Message-ID: <1139889150.651148.94560@g44g2000cwa.googlegroups.com>

Hi dawn, two levels of quotes can quickly career away from the main point (for instance I don't believe it is all just a case of nomenclature but I think we would get very bogged down along that path). The following lines stood out though:

>> Now if you are defining a new meaning for "data model" that corresponds
>> to an interface that is fine

> No, I am contending that is what Codd's def of data model is about. It
> is all about the representation of the data at the interface point
> between a client of a database and a database service.

I believe many would contest this, and think Codd's intention was the exact opposite - that his definition of a data model is all about getting away from representation, because information, with its complex internal interrelationships, may have a multitude of possible but equally valid representations. A data model surely aims to eliminate bias, structuring data and providing mechanisms to extract it out in any way we see fit for the task or information requirement in hand.

The blog often speaks of a UI data model and that the RM does not always "fit" it. I'd contest that a UI can "have" a data model in Codds sense of the term at all. Is a UI not rather a reflection of an underlying data model, like a fire casting a shadow on a wall? Manipulate the fire and one can get a different static shadow - the former is doing the work, and the latter it just an artefact. (Apologies for the cheesy analogy.)

All best, J. Received on Mon Feb 13 2006 - 21:52:30 CST