22. The article of claim 16 , wherein the instructions when executed cause the database system to further use at least one of indexing and statistics in generating a query plan for the database query in response to categorization of the predicate expression that is represented by the second representation.
23. The article of claim 22 , wherein the instructions when executed cause the database system to not use indexing and statistics in generating the query plan in response to categorization of the predicate expression that is represented by the first representation.