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[nycphp-talk] data modelling vs. db design

Tim Gales tgales at tgaconnect.com
Thu Oct 6 17:40:44 EDT 2005


> 
> Show me a "fully normalized" database supporting a web app, done close 
> to schedule and budget. I double dog dare ya. 

I know of two -- but they were conversions of existing databases,
which were already in pretty good shape. So maybe they don't count,
if you meant designed 'from scratch' for a web app.

...

> There is more than one way to normalize, because there are multiple ways 
> to define the data set. That's my point. In addressing the developers' 
> needs, the database design seems to come later. But of course we need a 
> solid database design to start; it has to be done first... hence the 
> recursive puzzle.But should we start with full normalized form? We would 
> never get development started. 

To address the developers' needs, the (physical) design typically does 
come (later) after the logical model is created. But, I don't know of 
anyone who advocates less than 3rd normal for a logical database design
(to be used in a relational DBMS).

After a few iterations the physical design can (and often is) 
denormalized from the logical model.

You can get your development started after your first 'cut' of a
physical design -- not "We would never get started."

"... should we start with a full normalized form?"

Yes.

-- 
T. Gales & Associates
'Helping People Connect with Technology'

http://www.tgaconnect.com



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