Re: Why spurious tuples with fifth normal form?

From: <stowellt_at_gmail.com>
Date: 15 Jun 2005 20:43:12 -0700
Message-ID: <1118893392.756491.79550@g49g2000cwa.googlegroups.com>

I really appreciate your info on this.

To answer your questions,

parameter_id refers to a chemical from a list (table) of chemicals, i.e.

parameter_id parameter

1.............silver
2.............gold
3.............cobalt

etc.

classification_id and url_id each link to similar tables. Basically, all three fields are part of the primary key. The whole point of the table is just to store the fact that silver in drinking water has a link to x website. Or gold in irrigation water has a link to the same website, or many websites, etc. So I don't think there are any mvd's because all three are inter-dependant (needed to identify a unique fact), not independant. Please correct me if I'm wrong.

As far as a join dependency, I'm not sure how to check for that. Is there an easy way? Thanks. Received on Wed Jun 15 2005 - 22:43:12 CDT