Query Scheduling and Site Selection Algorithms for a Cube-Connected Multicomputer System

Query scheduling and site selection algorithms for read-only quenes on a cube-connected multicomputer are presented. The assumed global system architecture was initially presented in [Fri87]. An architecture model for the system is provided, and via this model, a site selection algorithm which determines where to execute the upcoming operation sequence is developed. The query trees of queries entering the system are converted into operation sequence trees. Operation sequences belonging to a query are queued until the query is initiated. Two query selection policies are presented. A simulation comparing the two policies is described, and the simulation results are discussed. The scheduling restrictions which guarantee the avoidance of deadlock in both algorithms are presented.