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Thesis Defense - Doherty

A Multistate Service Based on Deltas and Its Application to Support Collaborative Work Applications
Computer Science PhD Candidate

In many applications, the representation and management of change is of primary interest, often being as important as the representation and management of state. The concurrency control policies of database management systems, which are focused on the maintenance of single consistent states, present an obstacle to the support of such applications. The research presented here has resulted in the development of theory to support new data storage techniques that overcome such obstacles without losing the other benefits provided by database systems. This theory, called Heraclitus[OO], is centered on the use of delta values, which capture state changes as first class objects available for manipulation by applications and users. The theory has been applied in the development of the H2O/SST data storage manager.

In the general area of cooperative work support, authoring systems and related applications are in particular need of support for flexible management of change as well as support for the resolution of resulting conflicts. To this end, this research has also developed an architecture by which H2O/SST can be used to support such applications. This architecture, called Coral, is designed to allow for the incorporation of application specific policies regarding the management of change and conflict. The principles of Coral have been demonstrated through the implementation of a prototype authoring system. Additionally, the development of applications based on Coral and H2O/SST is illustrated through an example system design. This system design includes the design of procedures to support authoring through delta values and the specification of particular delta values to support text documents.

Committee: Richard Hull, Assistant Professor (Chair)
Marcia Derr
Roger (Buzz) King, Professor
Benjamin Zorn, Associate Professor
Alexander Wolf, Professor
Department of Computer Science
University of Colorado Boulder
Boulder, CO 80309-0430 USA
May 5, 2012 (14:20)