RE: Picking the Tools -- Marrying processing models to data model s

["Al B. Snell" <alaric@alaric-snell.com>]

On Tue, 22 May 2001, Jonathan Borden wrote:

> The days of SQL databases are still today -- and what was done then is still
> proper. OO is still a great way to organize _software modules_. The problem,
> as I see it, is that software programmers, spending lots of time designing
> and writing software modules, start to try and view the entire world as a
> software module. Black box design was also around long before "OO" and still
> is the way to build stuff, what we need to keep straight is when to use a
> black box and when to use a clear box.

The principle of OO in data modelling is mainly to annotate the data
directly with descriptions of valid modifications and data extractions,
rather than relying on all the clients to do it properly.

data-driven way: define your list of customers, and let clients implement
adding notes to a customer or finding the mean age of a customer as they
see fit.

OODBMS way: define the customer list, but clients do not see the
representation; instead they see a list of operations on customers, to add
notes (but not to delete or change existing notes), and find the mean age.

XML is just a data represention. You can have a directly-client-accessed
XML datastore with the customer data in, or you can have an OODBMS that
has an XML-RPC interface and may or may not use XML internally as a data
store. It doesn't really affect the above issues :-)

> 
> -Jonathan
> 

ABS

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