An extended relational algebra for fuzzy multidatabases

Abstract

Recent trends in the database paradigm are to incorporate fuzzy sets to tackle imprecise and ambiguous information of real world problems. In this paper, using the concepts of fuzzy sets and possibility theory, a FTS relational model is developed to extend the TS-relational model by Ee Peng Lilm et al. (1999). The extended model integrates local fuzzy databases by merging the respective export fuzzy databases to generate a set of FTS relations of fuzzy multidatabase. A set of algebraic operations is defined to manipulate the FTS relations and their correctness is established. A set of algebraic rules is also presented to optimize FTS algebraic expressions.