Re: Sourcing Metadata for Database Independence
Date: Mon, 09 Aug 2004 10:38:08 -0700
Message-ID: <4117B680.8090409_at_metadata.com>
Dawn M. Wolthuis wrote:
>...I know there are some not-very-widely-used standards
> for metadata repositories -- are there industry standards for rules
> specifications other than SQL? ...
> I'm thinking more about the future than about what are the currently most
> accepted practicies. If you are not tied to a specific language or database
> up front and are developing a new software application to be deployed at
> many customer sites on many different databases, where/how would you source
> the metadata? Thanks in advance for your thoughts on this..
> --dawn
>
>
IMHO there are no standards for rules, beyond SQL; however, there are
some widely accepted "standards". The Horn clause is one: "a Horn
clause is a proposition of the general type (p and q and ... and t)
implies u, where the number of propositions combined by ands is as large
as we like."
and Cyc is another:
"(implies
(possesses ?x ?y)
(likesObject ?x ?y))"
http://www.cyc.com/cycdoc/ref/inferencing.html.
These are not strictly distinct because Cyc supports Horn clauses. I'm not going to go into an extended rant here. If you want to know more, let me know offline... Received on Mon Aug 09 2004 - 19:38:08 CEST