Research on Temporal Multi-valued Dependency Cover

As in traditional relational database, there also exists redundant data dependency in temporal database. Effective elimination of redundant data dependency is the foundation of further normalization for temporal databases. In order to eliminate redundant dependencies, cover of data dependency sets should be investigated. Coexist of multiple time granularities, temporal functional dependencies(TFDs) and temporal multi-valued dependencies(TMVDs) makes it more complicated to solve the cover problem of temporal database. To solve this problem, concepts of redundant temporal dependency, non-redundant temporal mixed cover and canonical temporal mixed dependency set are given. Corresponding cover algorithms are proposed which can solve the cover problem of mixed dependencies with both temporal functional dependencies and temporal multi-valued dependencies. It is the foundation for further normalization of temporal database.