Performance evaluation of objects with roles

The performance issues of objects with roles are addressed. In the authors´ previous paper, Double Signature Indexing Scheme (DSIS) was proposed for a dynamic object-oriented database programming language with role extension, called DOOR. DSIS can answer a wide range of queries including queries that exist only in dynamic environments. The index structure of DSIS also supports advanced operations like query relaxation and specification. They describe the types of queries that are supported by DSIS and show show DSIS evaluates the queries efficiently. They also formulate analytical models for retrieval cost and storage cost of DSIS