Set of metadata tables that describe fuzzy domains as well as columns of these types that include labels and the definitions of similarity relationships.
Published in Chapter:
Processing of Queries with Fuzzy Similarity Domains
Soraya O. Carrasquel (Universidad Simón Bolívar, Venezuela), Ricardo R. Monascal (Universidad Simón Bolívar, Venezuela), Rosseline Rodríguez (Universidad Simón Bolívar, Venezuela), and Leonid Tineo (Universidad Simón Bolívar, Venezuela)
Copyright: © 2016
|Pages: 41
DOI: 10.4018/978-1-4666-8767-7.ch004
Abstract
There are some data models and query languages based on the application of fuzzy set theory. Their goal is to provide more flexible DBMS that allow the expression of user preferences in querying as well as imprecision in data. In this sense, the FuzzyEER data model proposes four kinds of fuzzy attributes. One of them, named Type 3, consists of a set of labels provided of a similarity relation. An extension of SQL, named FSQL, allows the expression and use of fuzzy attributes. Nevertheless, FSQL does not allow using fuzzy attributes in some clauses based on data ordering, due to semantics problem. This chapter presents a solution for this problem in case of Type 3 fuzzy attributes. Main contribution consists in how to process queries involving such attributes by means of an extension to an existing RDBMS. Formal semantics, grammar, catalogue definition and translation schemas are contained in this chapter.