1. A method for classifying objects, the method comprising: identifying an object to be classified and a plurality of attributes associated with the identified object; grouping the plurality of attributes into a plurality of attribute patterns for the identified object, each attribute pattern comprising a unique set of the identified attributes; identifying a plurality of classes to be used in classifying the object; creating a plurality of sketch tables, each sketch table associated with one of the identified classes; using the sketch tables to associate a class value to each attribute pattern for each identified class and to determine a discriminating power for each attribute pattern; identifying attribute patterns having a discriminatory power above a given threshold; and using the identified attribute patterns having a discriminatory power above a pre-defined threshold to assign a class to the object.