Re: what data models cant do

"Kenneth Downs" <knode.wants.this_at_see.sigblock> wrote in message news:lqjml2-ks4.ln1_at_pluto.downsfam.net...
> mountain man wrote:
>> "Kenneth Downs" <knode.wants.this_at_see.sigblock> wrote elsewhere:

...[trim]...

> I found the article a good read, though as Alfredo says it may be only
> that
> flavor of model that is lacking.

He may have a point, after reading the author's comparison of various models, it is clear that the author favor's Barker diagrams over all other techniques of data modelling (as at 1999). [PDF: 221K]
http://www.essentialstrategies.com/documents/comparison.pdf

> This raises for me the entire question of data modelling and Kens First
> Law,
> "People Understand Tables Just Fine". Because people understand tables
> just fine, you do not need another layer of abstraction between people and
> tables. "Models" such as those in the article are only useful because a
> picture is worth a thousand words.

I think I am beginning to see that the method of modelling data directly from the tables has merit. Are you aware of any shortcomings in this approach?

>> 1) implied assumptions
>
> Well, here i'd have to say it is the analyst's role to dig all of those
> out
> and shed light on them.

Good point.

>Unstated assumptions are always bad when human
> beings endeavor to accomplish some goal.

>> 2) when optional relationships are activated
>
> This can be cleared up easily with more tables and more columns. If a
> database lacks the detail to be fully transparent, then the answer is to
> put the detail in.

Another good point.
Thanks.

Pete Brown
Falls Creek
Oz
www.mountainman.com.au Received on Tue May 17 2005 - 11:02:00 CEST