An implementation technique for data base management systems

A relationship is a correspondence between the members of two sets of data values. In order to physically represent a relationship we must indicate the existence of connections between member occurrences of the two sets involved. The collection of connections is said to specify a link between the two sets. The purpose of this paper is to precisely describe the distinct forms of a link. It is shown that there are three forms; each form capturing distinct physical characteristics. The three forms precisely define what is meant by 1:1, 1:N and N:M links.