A DYNAMIC DATA/CURRENCY PROTOCOL FOR MOBILE DATABASE DESIGN AND RECONFIGURATION By YANLI XIA A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE

of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science A DYNAMIC DATA/CURRENCY PROTOCOL FOR MOBILE DATABASE DESIGN AND RECONFIGURATION By Yanli Xia December 2002 Chair: Dr. Abdelsalam (Sumi) Helal Major Department: Computer and Information Science and Engineering Mobility is changing the way we design databases and their Database Management Systems (DBMS). For example the scenario in which all database users are ad-hoc users has been integrated in the Bayou and Deno projects. Both of them take an asynchronous, epidemic information flow and conflict avoidance-based (i.e., pessimistic) approach to ensure that all committed updates are serialized in the same order at all servers. Bayou uses a primary-copy scheme, while Deno takes a bounded weightedvoting one. In this thesis, we focus on flexible protocols for dynamic database design and reconfiguration. In particular, we introduce protocols and ideas that enable databases to be designed in such a way that their location, replication and even use semantics can be changed dynamically. We believe the flexibility of this approach is necessary given the uncertainty of user mobility.