A stream of tuples is received to be processed by a plurality of processing elements operating on one or more computer processors. Each processing element has one or more stream operators. A first stream operator adds a set number to a first tuple in the stream of tuples. The first tuple having the set number indicates that the first tuple is part of a set of tuples. Each tuple in the set of tuples contains the set number. It is determined to delete the set of tuples, and a set of stream operators deletes tuples containing the set number.