An Equivalence between Dependencies in Nested Databases and a Fragment of Propositional Logic

Abstract

We extend the result on the equivalence between functional and multivalued dependencies in relational databases and a fragment of propositional logic. It is shown that this equivalence still holds for functional and multivalued dependencies in databases that support complex values via nesting of records and lists. The equivalence has several implications. Firstly, it extends a well-known result from relational databases to databases which are not in first normal form. Secondly, it characterises the implication of functional and multivalued dependencies in complex-value databases in purely logical terms. The database designer can take advantage of this equivalence to reduce database design problems to simpler problems in propositional logic. Furthermore, relational database design tools can be reused to solve problems for complex-value databases.