Derived Fact Types in Object-Role Modeling

When the penny drops

For years now I have marveled at Derived Fact Types in Object-Role Modeling.

Derived Fact Types provide the ability to turn your database into an expert system or or knowledge base system, implementing rules/inference rules over the data in your database.

In the 1980s, 90s and early 2000s there were many papers written on expert/knowledge base systems and the potential of SQL/relational databases…if only there were a way to quickly turn rules into SQL and use SQL itself as…