7. The method of claim 1 , further comprising stratifying the representative workload into at least two strata including a first stratum and a second stratum, and determining a minimum number of queries to achieve the probability of correct selection of the sample workload, and wherein updating the sample workload includes selecting the minimum number of queries from the first stratum.
9. The method of claim 7 , wherein stratifying the representative workload includes determining a query template for each query contained in the representative workload, determining an average cost of execution for each determined query template; and ordering the queries of the representative workload based on the average cost per template, and splitting the representative workload based on a split point of the ordered queries.