Evaluation of the Set of Keys in Relational Schema by Means of Analytical Graphs

An important problem in relational database system, (?)e., algorithm for evaluating the set of keys in relational scheme is discussed in this paper. We define the analytical graph from which we deduce a series of properties and obtain a theorem for evaluating the set of keys in relational schema. Finally we point out that there are many other important applications of analytical graph in relational database systems.