FRDBMS for imprecise queries based on GEFRED model

Abstract

When users work with usual software tools they have to change their many valued logical thinking (approximate reasoning) into the two-valued computer logic. Although the Structured Query Language (SQL) is a very powerful tool, it is unable to satisfy needs for data selection based on linguistic expressions and degrees of truth. In this paper, we are interested in flexible querying that is based on fuzzy set theory. Medina et al. have developed a server named fuzzy SQL, supporting flexible queries and based on a theoretic model called GEFRED. To model the flexible queries and the concept of fuzzy attributes, an extension of the SQL language named fuzzy SQL has been defined. The FRDB is supposed to have already been defined by the user. In this paper, the work of medina et al. has been extended to implement a new architecture of fuzzy DBMS based on the GEFRED model. This architecture is based on the concept of weak coupling with the DBMS SQL Server.