An efficient indexing scheme for objects with roles

Abstract

Indexing schemes for traditional Object-Oriented Databases (OODBs) are divided into two catalogues: class hierarchy indexing and nested indexing. Since most of these systems are static in nature, dynamic operations like class versioning and role playing are not supported by traditional indexing schemes. In order to support these dynamic query operations, a more sophisticated indexing scheme is needed. In this paper, we present the Double Signature Indexing Scheme (DSIS) for a dynamic object-oriented database programming language with role extension, called DOOR. It supports retrievals of a large range of queries including class relation queries, nested queries as well as queries that exist only in dynamic environments like qualification and versioning queries. Query relaxation and specification are also supported by the index structure. We describe the index structure of the indexing scheme and show how the index structure supports dynamic operations as well as static operations. In addition, we present the operations of the indexing scheme and demonstrate how the operations of the new indexing mechanism handle different kind of queries.