The relational model in information retrieval
Robert G. Crawford · Journal of the American Society for Information Science · 1981
Abstract The relational model has received increasing attention during the past decade. Its advantages include simplicity, consistency, and a sound theoretical basis. In this article, the naturalness of viewing information retrieval relationally is demonstrated. The relational model is presented, and the relational organization of a bibliographical database is shown. The notion of normalization is introduced and first, second, third, and fourth normal forms are demonstrated. Relational languages are discussed, including the relational calculus, relational algebra, and SEQUEL. Numerous examples pertinent to information retrieval are presented in these relational languages. Advantages of the relational approach to information retrieval are noted.