Re: How to model searchable properties of an entity

"Bernard Peek" <bap_at_shrdlu.com> wrote in message news:pXPshxP7CzIBFwKF_at_shrdlu.com...

> The entity-attribute-value system is an alternative but I don't believe
> it is much better, and I speak as one who has built such systems.You
> still need every user to have pretty much the same training as a DBA. If
> you can't ensure that all of your users are of that calibre then the
> system will rapidly become unworkable. I sometimes use an e-a-v system
> as part of the process of designing a new system, but I haven't yet
> handed over a finished design with it still in place.

Bernard,

Good post. I like the way you outline the trade offs in dealing with a bad but real situation.

One point I want to make clear about the EAV solution. At the conceptual level of data abstraction, this is
tantamount to giving the users CREATE TABLE or ADD COLUMN privileges. In essence, what we are permitting the
users to do is revise and extend the portion of the subject matter modeled by the database.

That is why, IMO, "You still need every user to have pretty much the same training as a DBA."

Intelligent use of EAV and intelligent use of CREATE TABLE, ADD COLUMN require the same level of sophistication concerning mapping the subject matter into data. At other levels of abstraction they are, of course, different. But this is what the proponents of EAV sometimes overlook. People who can't do data modeling can't use EAV. Received on Wed Aug 18 2004 - 15:35:49 CEST