Embodiments of the disclosure provide a method, system, and computer program product for managing a windowing operation. The method for grouping processing of a stream of tuples with each tuple containing one or more attributes can include receiving the stream of tuples to be processed by a plurality of processing elements operating on one or more computer processors. The method can also include processing, with a first processing method, a group of tuples from the stream of tuples into a grouping window. The method can also include processing, with a second processing method, a subgroup of tuples from the group of tuples into a subgrouping window. The second processing method can include identifying a sub-membership condition.