The design of ¬ 1NF relational databases into nested normal form

Abstract

We develop new algorithms for the design of non first normal form relational databases that are in nested normal form. Previously, a set of given multivalued dependencies and those multivalued dependencies implied by given functional dependencies were used to obtain a nested normal form decomposition of a scheme. This method ignored the semantic distinction between functional and multivalued dependencies and utilized only full multivalued dependencies in the design process. We propose new algorithms which take advantage of this distinction, and use embedded multivalued dependencies to enhance the decomposition. This results in further elimination of redundancy due to functional dependencies in nested normal form designs.