The design of relational database schemes based on the elementary relationships of attributes: Computing of the closure of a set of attributes for one type of relationship

In this paper we present the following concepts: “the elementary relationships of attributes”, “the type of elementary relationship of attributes”. These concepts are used for the method of design of relational database schemes. We present special case, in which an initial set of relationships consists of relationships of 1..M:0..1 type only. For this special case we propose: the set of inference rules, algorithm of computing of the closure of a set of attributes with respect to a set of relationships of 1..M:0..1 type and algorithm to test the membership in the closure of the elementary relationships of attributes for some relationship of 1..M:0..1 type. Furthermore, we propose a proof of the correctness of the algorithm of computing of the closure of a set of attributes with a respect to a set of relationships of 1..M:0..1 type.