8. The system of claim 7 wherein computer program instructions configured to assign a selectivity factor to each predicate further comprise computer program instructions configured to probe database statistics.
7. A system for query expression evaluation for query optimization, the system comprising a computer processor, a computer memory operatively coupled to the computer processor, the computer memory having disposed within the computer memory, computer program instructions configured to: receive a query including a plurality of predicates; create a truth table representing all of the possible solutions to the query; condense the truth table including identifying a plurality of intersections of the truth table, the plurality of intersections including each predicate of the query; assign a selectivity factor to each predicate; determine in dependence upon the selectivity factors for each predicate a selectivity rating for each of the intersections of the truth table; select one or more of the intersections in dependence upon the selectivity rating, wherein selecting one or more of the intersections in dependence upon the selectivity rating further comprises: determining whether any of the intersections has a selectivity rating of zero; and when any of the intersections has a selectivity rating of zero, selecting the intersections having a selection rating greater than zero; determine in dependence upon the selected intersections a percentage of rows in a database table returned by the query; and provide the percentage of rows in the database table to an access plan generator for query optimization.