A Planner / Optimizer / Executioner for Context Mediated

This thesis describes the design and implementation of a planner/optimizer/executioner (POE) for the COntext INterchange (COIN) system, . The POE takes a contextmediated query from the Mediation Engine of the system and returns the results of the query to the user of the system. Since context-mediated queries are composed of sub-queries to multiple data-sources, the POE plans the execution order of the subqueries , executes each sub-query, composes the results and returns this as the answer of the mediated query. The thesis also describes the design of helper components of the POE such as the Capability Checker. Finally, the thesis describes a preliminary performance analysis study which was used to determine the allocation of costs in the COIN system. Thesis Supervisor: Dr. Michael Siegel Title: Principal Research Scientist, Sloan School of Management