DOOR=‘Object with Roles’+‘Schema Evolution’

Abstract

Roles and schema evolution are becoming popular research issues in object-oriented databases, and have been proven to be useful in dynamic and evolving applications. However, not much work has been done on discussing their differences. In particular, there is no programming language or database system which includes and integrates both mechanisms. Our objective is to integrate these two mechanisms such that a role is used to model evolving objects and schema evolution is used for the flexible design of dynamic and evolving systems. The resultant language is called DOOR, a dynamic object-oriented database programming language with role extension, which incorportants both roles and schema evolution constructs. Important issues which need to be addressed to integrate these two approaches are discussed in this paper.