Re: Impact of XML on Data Modeling

On Wed, 30 Jan 2008 22:12:40 -0000, Michael Kay <mike@saxonica.com> wrote:

>> Nomenclature is a funny old thing.  I would argue that you
>> don't access data via a logical model, you access it via a
>> physical model.
>
> I'm afraid I was brought up on the notion that the logical model is what
> programmers can see, the physical model is what's hidden from their  
> sight. I
> think that usage is very common in the database world. Of course, with  
> XML,
> very little is hidden - until you put it in a database.

Yes, the way that the terms "logical model" and "physical model" are used  
in the relational database world is a continual source of confusion.  It  
has a different meaning to the general concepts of  
conceptual/logical/physical model, and the relational database terms  
really refer to two layers of a physical model.

Cheers, Tony.
-- 
Anthony B. Coates
London, UK
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