Re: How to model searchable properties of an entity

In message <cfvhht02nig_at_enews3.newsguy.com>, Karel Miklav <karel_at_inetis.spppambait.com> writes
>Bernard Peek wrote:
>> If you are going to have the metadata evolving as the database is
>>built then there is no alternative but to have highly trained users
>>with an understanding of information management. There are several
>>different ways of using them but this basic requirement is pretty
>>much unavoidable.
>
>There is an alternative. Although you may not have a clue what the
>metadata will look like you can implement its functional categories in
>your software. Then require users to categorize the metadata as they
>enter it.

As I read it that requires you to know enough about the unknown metadata to be able to define categories for it. That's how the Dewey classification system works. You define 10 major categories and fit new entries into one of them. The problem is that one of these classes is always "miscellaneous" and that particular bin always ends up a mess.

The difficulty with handling unknowns is that they are unknown in unknown ways. You can't be certain that the next one will fit into any of the categories that you created. Unless, of course, you make the system completely generic. That's the e-a-v system.

>
>Principle is the same, but if lots of folks will use this application
>it might be easier to add some code than reeducate the whole industry.

You can take steps to reduce the effort needed but you can't eliminate the work completely and all of the users still need to be fully trained. If you have the ten Dewey classes you still have to train all of your librarians about boundary conditions. For instance which class does computing belong in? You have a choice of mathematics, electronics, logic or miscellaneous.

-- 
Bernard Peek
London, UK. DBA, Manager, Trainer & Author. Will work for money.