Database Decomposition into Fourth Normal Form
Gösta Grahne, Kari‐Jouko Räihä · 1983
Abstract. We present an algorithm that decom-poses a database scheme when the dependency set contains functional and multivalued dependencies. The schemes in the resulting decomposition are in fourth normal form and have a lossless join. Our algorithm does not impose restrictions on the allowed set of dependencies, and it never re-quires the computation of the full closure of the dependency set. Furthermore, the algorithm works in polynomial time for classes of dependencies that properly contain conflict-free dependency sets. 1.