1. In a computing environment, a method performed on at least one processor comprising: obtaining one or more rule patterns corresponding to one or more transformation rules of a transformation rule-based query optimizer of a database management system; generating one or more queries based upon the one or more rule patterns; mapping the one or more queries to the one or more transformation rules to generate a test suite for query processing; providing the test suite to the transformation rule-based query optimizer for query processing; receiving information from the database management system that indicates which of the one or more transformation rules are exercised during the query processing; determining a test suite of queries for testing the one or more transformation rules; and compressing the test suite of queries for testing the one or more transformation rules into a subset of queries, including processing data corresponding to a graph comprising a plurality of rule nodes each representing one or more rules and a plurality of query nodes representing queries, to select the transformation rule based upon cost information associated with the query nodes and one or more criteria including that each rule is exercised a specified number of one or more times by the subset.