The present invention is directed towards a diagnostic system for a database system. The diagnostic system includes a grouping module for assigning a grouping identifier to each query received by the database system; and a statistics collection module. The statistics collection module includes a query processing statistics module for obtaining processing statistics corresponding to each query; a group statistics compilation module for compiling processing statistics for each query by the query's grouping identifier; and group data storage for storing compiled processing statistics. A method is also disclosed for generating database diagnostic data.