Generating Parallel Execution Plans with a Partial-Order Planner

Many real-world planning problems require generating plans that maximize the parallelism inherent in a problem. There are a number of partial-order planners that generate such plans; however, in most of these planners it is unclear under what conditions the resulting plans will be correct and whether the planner can even find a plan if one exists. This paper identifies the underlying assumptions about when a partial plan can be executed in parallel, defines the classes of parallel plans that can be generated by different partialorder planners, and describes the changes required to turn ucpop into a parallel execution planner. In addition, we describe how this planner can be applied to the problem of query access planning, where parallel execution produces substantial reductions in overall execution time. Introduction There are a wide variety of problems that require generating parallel execution plans. Partial-order planners have been widely viewed as an effective approach to generati..