Rough Relational Operators and Rough Entropy in Rough Relational Database

The relational database model (RDM), proposed by Codd, has been proven to be a very useful model in many applications. The inherent of the RDM is effective for precise and unambiguous data. However, real world applications often include imprecise and uncertain information. Therefore, Beaubouef et al. proposed the rough relational database model (RRDM) for the management of uncertainty in relational databases. In the RRDM, a tuple of a rough relation can have multi-values on some attributes, which is forbidden in the RDM. In this paper we give some new definitions for rough relational operators and rough entropy of rough relations in the rough relational databases. Furthermore, we discuss the possible connections between rough relational operators and rough entropy.