Normalisation

In his seminal paper on the relational data model, E.F. Codd formulated a number of design principles for a relational database (Codd, 1970). These principles were expressed in terms of three normal forms. The process of transforming a database design through these three normal forms is known as normalisation. By the mid-1970s third normal form was shown to have certain inadequacies and a stronger normal form, known as Boyce-Codd normal form was introduced (Codd, 1974). Subsequently, Fagin introduced fourth normal form and fifth normal form (Fagin 1977, 1979).