8. The method of claim 7 further comprising: implementing an approximation algorithm as a utility of the DBMS.
8. The method of claim 7 further comprising: implementing an approximation algorithm as a utility of the DBMS. 9. The method of claim 8 wherein the approximation algorithm provides a near optimal solution to an NP-hard n-gram selection problem, the method further comprising: providing the approximation algorithm with a definable ratio bound of the optimal solution.