A system and method for determining optimal query plans within a distributed processing system. The system includes a query optimizer for receiving a query and generating a query plan for execution by the distributed processing system; a repository including statistics related to prior executed query plans; a plan execution engine for receiving and executing the query plan, collecting statistics corresponding to the query plan, and storing the statistics and optimizer usage metadata corresponding to the query plan and prior executed query plans in the repository. The system further includes a statistics advisory tool for mining the metadata to generate a collection of histogram statistics and storing said histogram statistics in the repository. When generating a query plan, the query optimizer searches the statistics repository for statistics, including histogram statistics, useful to the generation of the current query plan and uses selected statistics from the repository to generate the query plan.