In this thesis, a method to handle recursion efficiently in interfacing Prolog with relational data base systems is proposed. Our system is based on Reiter's compiling method and uses Predicate Connection Graph(PCG) proposed by Shapiro et al. for compilation.
In the case of a program to contain recursive rules, Prolog inference system obtains informations for answer expressions for each recursive rule and sends them to backend relational data base systems.
In relational data base systems, Answer expression generator generates answer expressions by using the informations received from Prolog inference system. The answer expressions are processed successively by Query planner, Query transformer, and Evaluator.
By using Answer expression generator, unnecessary inferencing and communications are eliminated and evaluation results obtained previously are used in the next evaluation.
