Computer-implemented method, system, and computer program product for processing data in an out-of-order manner in a streams computing environment. A windowing condition is defined such that incoming data tuples are processed within a specified time or count of each other. Additionally, the windowing condition may be based on a specified attribute of the data tuples. If the tuples are not processed within the constraints specified by the windowing condition, the unprocessed tuples may be discarded, i.e., not processed, to optimize operator performance.