Enhanced ER to relational mapping and interrelational normalization

This paper develops a method that maps an enhanced Entity-Relationship (ER+) schema into a relational schema and normalizes the latter into an inclusion normal form (IN-NF). Unlike classical normalization that concerns individual relations only, IN-NF takes interrelational redundancies into account and characterizes a relational database schema as a whole. The paper formalizes the sources of such interrelational redundancies in ER+ schemas and specifies the method to detect them. Also, we describe briefly a Prolog implementation of the method, developed in the context of a Computed-Aided Software Engineering shell and present a case study