Views, authorization, and locking in a relational data base system
Donald D. Chamberlin, Jim Gray, Irving L. Traiger · 1975
In the interest of brevity we assume that the reader is familiar with the notion of a relational data base. In particular, we assume a familiarity with the work of Codd or Boyce and Chamberlin. The examples in this paper will be drawn from a data base which describes a department store and consists of three relations: