Re: Modelling Considered Harmful

Bernard Peek wrote:

>> I don't understand this point at all. To me it seems almost a tautology
>> that databases are models of reality (unless of course they're modelling
>> some virtual world that doesn't exist outside the database).

Hmm maybe it comes down to semantics then, because the way I look at it,  the metadata describes a top-level model of reality, and the data just provides a more detailed model of reality.

For example, consider a group of employees I want to model. For simplicity assume I'm using a single table.

The metadata that descibes that table gives me a very broad model of reality: it tells me that I'm dealing with a group of people who have certain attributes.

But it doesn't tell me who those people are or what values the attributes have for each person - for that I have to supply the row data. But to me that's still a model; it's just more detailed, giving me the names, departments etc. for each person. Each row is a model of a person, if you like.

Maybe I'm belabouring an unimportant point though and it just comes down to the definition of the word "model" in different contexts.

I agree that what we commonly refer to as "data modelling" is all about metadata, but I still think data itself is also about modelling.

Paul. Received on Sat May 07 2005 - 10:04:07 CDT