there is disclosed a system and method for executing multiple distinct aggregate queries . in an embodiment , the method comprises : providing at least one counting bloom filter for each distinct column of an input data stream ; reviewing count values in the at least one counting bloom filter for the existence of duplicates in each distinct column ; and if necessary , using a distinct hash operator to remove duplicates from each distinct column of the input data stream , thereby removing the need for replicating the input data stream and minimizing distinct hash operator processing . also , the use of counting bloom filters for monitoring data streams allow an early duplicate removal of the input stream of data , resulting in savings in computation time and memory resources .