Extending semantics of relational operators for vague queries

Abstract

Queries with vague qualifications are taking growing interests in various applications such as decision supporting systems and advice giving systems. To accomodate the vagueness handling capabilities into the widely used relational framework, Level-1 Fuzzy Relational Data Model(FRDM-1) has been proposed in [3]. In this paper, we generalize the model to acquire more practical usefulness. We also describe how non-fundamental relational operators such as join and division can have extended semantics in the proposed model.