Fuzzy databases. Principles and applications. With contribution by Patrick Bosc. (English) Zbl 0853.68086

International Series in Intelligent Technologies. 5. Dordrecht: Kluwer Academic Publishers. x, 226 p. (1996).
This volume provides an interesting and thorough account of many of the issues related to the design and the implementation of fuzzy databases. The material presented in the book is divided into six chapters: database fundamentals, relational databases and fuzzy sets background, similarity-based models, possibility-based models, alternative database models and approaches, commercial and industrial applications. The six chapters can be ideally grouped into three major parts: the first one, including chapters 1 and 2, provides background concepts; the second one, consisting of chapters 3, 4 and 5, presents main approaches to fuzzy information management in databases; finally, the third part, including just chapter 6, illustrates commercial fuzzy database systems.
In more details, the first chapter provides an introduction to basic issues of database theory. In particular, it introduces principles of database design, surveys on database models and illustrates techniques adopted in conventional databases for managing imprecise information. The second chapter has two parts: the former is devoted to a more detailed illustration of relational database principles; the latter provides an overview of basic fuzzy set theory. The volume core begins with chapter 3, where similarity-based models are presented. In particular, the chapter first accounts for several approaches based on similarity or proximity relations and then discusses fuzzy query languages and some related issues (e.g., fuzzy functional dependencies, database security). The following chapter deals with approaches to imprecise information management based on possibility theory. As for chapter 3, in the various sections of chapter 4 both basic theory, models, query languages and related issues are discussed. Chapter 3 and 4 altogether provide insights into the main stream of the research developed on fuzzy relational databases. Chapter 5, instead, surveys alternative approaches to fuzzy databases. In more details, this chapter first considers the entity-relationship model and the possibility of obtaining fuzzy extensions of the E-R model. Then, CODASYL databases are analyzed and their fuzzy extension illustrated. Third, O-O database models are dealt with and the issue of devising fuzzy object-oriented data models is considered. Then, an illustration of the rough sets approach is provided and the possibility of simultaneous adoption of fuzzy and rough sets techniques in databases is analyzed. Finally, the interesting application case of geographical information systems is discussed. Chapter 6 closes the book with a reasoned overview of commercial fuzzy database systems. All chapters end with a list of references for the presented material.
In our opinion, the author did a remarkable job in writing this volume. Indeed, the book is characterized by a (not easily found) balance between the need to be accessible to non-experts and the need to be an interesting source of information for people involved in this specific field. In particular, we found appropriate the organization the author adopted in the core chapters 4 and 5 to have two orthogonal direction in the presentation: the first, which can be observed through the two chapters, spanning different approaches to fuzzy databases, the second one, which is evident within each of these chapters, spanning the various aspects related to database management: models, query languages, design, security and so on. Furthermore, the book has the merit of introducing the various concepts turning around the subject of fuzzy databases smoothly often accompanying technical definitions with explanatory examples. Another aspect we have appreciated in this book is the attention the author demonstrated towards (to the date, to a large extent only potential) practical applications of fuzzy database systems.
In summary, we think this book represents an important contribution to the dissemination of novel ideas developed in the area of fuzzy databases and we would certainly suggest this volume as a very useful reading for anyone interested in the problems related to the management of imprecise data in information systems.
Reviewer: L.Palopoli (Rende)


68P15 Database theory
68-02 Research exposition (monographs, survey articles) pertaining to computer science
68P20 Information storage and retrieval of data