Towards Restructuring and Normalization of Types in Databases

The equivalence- preserving transformation and normalization of types inobject-oriented databases are discussed. Specifically a normal form of typesbased on set-theoretic equivalence is proposed, rewrite rules which transformtypes into normal forms are presented, and the uniqueness of normal form andthe completeness of rewrite rules are proved. The emphasis of this work ison normal forms and corresponding rewrite rules. It provides a new formalapproach for the study of restructuring of database schema and o…