I've decided I need to first document business rules for a project I'm
working so I can design and build a more robust and hopefully
extensible and elegant database.

As yet there are no documented rules to constrain how we conduct our
business let alone inform the data model (we have what Barbara von
Halle termed "Business Ramblings" - see many online references).

In the absence of rules my ER models are at the mercy of rule changes.
I'm hoping that by documenting them I may better inform the rule
'makers', may identify the likely impacts of changes to rules and have
a better chance of developing the 'right' data model and physical
implementation.

So I've turned to the Business Rules Group to explore their ER model
for managing Business Rules. Their complete Business Rules Model E-R
diagram is at document "Defining Business Rules ~ What are they?" see
Appendix A at http://www.businessrulesgroup.org/fi...per/br01aa.htm

Now, the Business Rules Group model displays RECURSIVE MANY-TO-MANY
relationships - see the concept "Business Rule Statement" and the
concept "Policy".

What's the go there?

How do I take a recursive n:m and make it conforming in the logical and
physical models?

[I note Joe C has many papers on similar topics and I recently bought
Trees and Hierarchies - many thanks Joe for this contribution. I have
also referred to my various texts without much luck].

Would appreciate pointers to resources that would assist.

Cheers
Greg.

Hmmm, deathly quiet on business rules..

So, asked and answered I think (courtesy of TDAN et al. -
http://www.tdan.com/i021ht04.htm)

In the logical model, create a new entity that hold the two FKs - one
for each instance of the determining entity that participates in the
(recursive) relationship.

Greg

The fact that you are doing this is great start that most people never
make.

Barbara has been on the money for a long time ..

The best I have been able to do for general graphs is an adjacency
model with the the (from_node, to-node, edge_info) and really ugly
queries.

Many thanks for the royalty check!