Object-oriented data models: a perspective and comparative review

Abstract

An object-oriented database management system supports complex objects with identity and allows arbitrary connectivity amongst objects The behavioural aspects of ob jects are incorporated into modelling formalisms by associating operations with classes of objects. These features favour data base modelling in application areas such as engineering design, office information systems and knowledge base management systems. This paper reviews the research efforts in the area of object-oriented database modelling. The object-oriented para digm and abstraction mechanisms are briefly discussed. The conceptual schema and data operations in an object-oriented data model are described. Ongoing efforts in creating object- oriented DBMS are classified into three categories. (1) those that are directly based on the object-oriented paradigm; (2) exten sions to relational systems. (3) experimental toolkits (or stor age systems). A review of the salient features of some sample prototype efforts is presented. This is followed by a compan son of these prototype models on the basis of criteria essential to database modelling.