This volume presents the results of approximately 15 years of work from researchers around the world on the use of fuzzy set theory to represent imprecision in databases. The maturity of the research in the discipline and the recent developments in commercial/industrial fuzzy databases provided an opportunity to produce this survey. In this introduction we will describe briefly how fuzzy databases fit into the overall design of database systems and then overview the organization of the text. FUZZY DATABASE LANDSCAPE The last five years have been witness to a revolution in the database research community. The dominant data models have changed and the consensus on what constitutes worthwhile research is in flux. Also, at this time, it is possible to gain a perspective on what has been accomplished in the area of fuzzy databases. Therefore, now is an opportune time to take stock of the past and establish a framework. A framework should assist in evaluating future research through a better understanding of the different aspects of imprecision that a database can model [ 1 l
CONTENT
1 Database Fundamentals -- Database Principles -- Database Design -- Database Models -- Imprecision in Conventional Databases -- References -- 2 Relational Databases and Fuzzy Sets Background -- Relational Database Concepts -- Fuzzy Set Theory -- References -- 3 Similarity-Based Models -- Basic Fuzzy Databases Approaches -- Similarity-Based Models -- Proximity-Based Models -- Distinguishability Data Model -- Querying Fuzzy Relational Databases -- Fuzzy Functional Dependencies -- Information-Theoretic Measures -- Fuzzy Database Security -- References -- 4 Possibility-Based Models -- Weighted Tuples -- Possibility-Based Fuzzy Relational Databases -- Query Languages -- Related Database Issues -- Implementation Issues -- References -- 5 Alternative Database Models and Approaches -- Entity-Relationship Models -- Network Data Models -- Object-Oriented Models -- Rough Sets Approach -- Geographical Information Systems -- References -- 6 Commerical and Industrial Applications -- Fuzzy Querying Front End Interfaces -- Special Purpose Systems -- Commerically Available Products -- Summary -- References
