Compiling Horn-Clause Rules in IBM's Business System 12 - an Early Experiment in Declarativeness
Ghica van Emde Boas-Lubsen, Peter van Emde Boas

Abstract:
Compiling Horn­Clause Rules in IBM's Business System 12:
  an Early Experiment in Declarativeness
Ghica van Emde Boas­Lubsen, Peter van Emde Boas

The tight connection which exists between the fragment of Prolog now known by
the name Datalog [28] and the various calculi and algebras for Relational 
Database Systems was observed at several places in the late 70­ies and early 
80­ies. The problem was to make this idea operational and to build a system 
which implemented it. Such systems today are known as Deductive Databases.
We describe the history of a hardly known project from the mid 80­ies where a 
prototype realizing this goal was produced. We explain why the Relational
Database system called Business System 12, developed by IBM in the Netherlands,
and which became operational in 1983, turned out to provide the right 
functionality. We also indicate how this project influenced subsequent projects
aimed at enhancing the degree of declarativeness in interfaces with database 
systems.

"What we understand we can formalize; what is formalizable can be automated, 
and you will discover that someone has built it."