1. A method, comprising: creating a processing data set of records, wherein each of the records contains data specific to a sub-task from a set of actual sub-tasks and contains a reference to data shared by the set of actual sub-tasks, and wherein a number of the records is equivalent to a number of the actual sub-tasks in the set of actual sub-tasks; with each mapper in a set of mappers, receiving one of the records of the processing data set; and executing an assigned sub-task using the received one of the records to generate output; and with a single reducer, reducing the output from each mapper in the set of mappers to determine a task result, wherein at least one of the steps is carried out by a computer system.