Re: what exactly is the conceptual model?

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Mon, 02 Jul 2007 19:47:22 -0300
Message-ID: <46898069$0$4297$9a566e8b@news.aliant.net>

Roy Hann wrote:

> "Senges" <csengstock_at_gmail.com> wrote in message
> news:1183410491.409439.296070_at_57g2000hsv.googlegroups.com...
>

>>hi list,
>>
>>i know about the basic distiction of data modelling as i heard it in
>>my db couse:
>>
>>* semantic model      --> ERM
>>* logical model          -->  relational schema / XML schema
>>* physical model       --> hash tables / how to handle stuff on the
>>harddisk

>
> Well I take your word that you heard this stuff on a course that was
> supposed to be about databases (databases? database systems?). I take
> exception to pretty much all of it, for a variety of reasons.
>

>>and i heard about the conceptual modell / conceptual schema /
>>conceptual modelling. however:

>
> [much snippage of erudite-looking stuff]
>
> The conceptual model is an informal ad hoc description of the
> business'/users' informal understanding of the enterprise of interest.
>
> Roy
>
> PS: I notice Date provides no definition of the conceptual model in The
> Relational Database Dictionary. I wonder if that is one that he
> deliberately omitted because he thinks the word "model" is overloaded beyond
> what "it can reasonably be expected to bear"?

I still rely on the ISO/IEC standard vocabularies where the conceptual level of discourse deals with information, and the logical level of discourse deals with data, which is that subset of information suitably represented for machine processing. However, I personally think of data more as information suitably represented for symbolic manipulation. Received on Mon Jul 02 2007 - 17:47:22 CDT