A fundamental concept in database management systems (DBMSs) is that of physical data independence, i.e., the ability to modify the physical database scheme without requiring a rewrite of the software that implements the DBMS or the application programs that use the data. This concept enables a DBMS to support multiple applications and at the same time optimize the physical design of each database to provide each application with the highest performance available. This research focuses on alternative implementations of database management systems and investigates: (1) physical data independence, (2) tools and techniques that can optimize the physical design of data for a given application, and (3) techniques for dynamic reorganization of data in the presence of changing patterns of data access. The main objective is to maximize the performance of a system, and whenever appropriate, to utilize parallelism. Some of this research has been conducted in the context of the relational data model. This research project concentrates on the object-oriented data model and other current and emerging data models (i.e., a family of logical constructs for representation and manipulation of data). This research is expected to significantly enhance the performance of the current and next generation DBMSs. //
