View mechanism for schema evolution in object-oriented dbms

Bellahsene, Z
Bellahsene, Z
Proc. BNCOD, LNCS 1094
Citations range: 
10 - 49

This paper discusses the topic of using view mechanism to simulate schema modifications without database reorganisation in Object Oriented Database Systems. Our approach allows each user to specify the schema modifications to his own virtual schema rather than to the base schema shared by many users. One of the main advantages provided by this approach is the preservation of the independence of existing application programs from the schema evolution. The most important issue concerns the control and sharing of the information introduced by capacity-augmenting views. Furthermore, capacity augmenting schema modifications cannot be unambiguously propagated to the base schema when the related virtual class is derived from several classes. This paper proposes a solution based on the definition of a multi-level schema architecture, emphasising:
(i) The integration of this information into a federated schema.
(ii) Improvement of the sharing and re-use of information between views
Furthermore, we argue that view mechanism capabilities must be enhanced in order to be used as a uniform framework to manipulate both the schema and the database, thereby providing full data independence.