17. The computer program product of claim 16 wherein computer program instructions configured to determine a projected percentage of rows in the database table determined in dependence upon the subset of intersections further comprise computer program instructions configured to: determine a percentage of rows in the database table returned by each of the intersections of the subset; and sum the percentage of rows in the database table returned by each of the intersections of the subset; determine a scalar in dependence upon the selectivity ratings of the intersections of the subset; and scale the summed percentage in dependence upon the scalar.
16. The computer program product of claim 13 wherein computer program instructions configured to select one or more of the intersections in dependence upon the selectivity rating further comprise computer program instructions configured to: select a subset of intersections, each subset of intersections including each predicate in the query; and wherein determining in dependence upon the intersections a percentage of rows in a database table returned by the query further comprises determining a projected percentage of rows in the database table determined in dependence upon the subset of intersections.