Designing the reengineering service for the DOK federated database system

Addresses the design of the reengineering service for the DOK (Distributed Object Kernel) federated database. This service allows the hiding of the heterogeneity of databases involved in a federation by generating object-oriented representations from their corresponding schemata. We propose a complete methodology that supports the identification and the translation of both the explicit and implicit information. The identification of object-oriented constructs is performed by classifying a relational schema into different categories of relations, namely base, dependent and composite relations. The main difficulty in designing the reengineering service relies on the distinction between the different types of relationships amongst classes. Our approach deals with this problem by analysing relations according two types of correlation: (i) the degree of correlation between the external and primary keys, and (ii) the degree of correlation between sets of tuples in the relations. Examining these correlations uncovers implicit relationships contained as well-hidden classes in a relational schema