1. A method, comprising: executing queries, comprising accessing a set of data tables for each of said queries, wherein said data tables summarize common portions of said queries; and during said executing of said queries, accessing a required data table from a cache if said required data table is present in said cache, creating said required data table if said required data table is not present in said cache and if a benefit of accessing said required data table exceeds a cost of creating said required data table, and storing created data tables in said cache.