1. A system for processing a stream of tuples, comprising: one or more computer processors; one or more memories to store two or more processing elements, the processing elements to receive two or more tuples to be processed, the processing elements operating on the one or more computer processors, the two or more processing elements including: a first processing element initially configured to transmit a first output stream to a second processing element, the tuples of the first output stream having first and second attributes, the second processing element initially configured to transmit a second output stream to a third processing element, the tuples of the second output stream having the first and second attributes; a unit to: determine whether first and second conditions are met, the first condition being that the first attribute is to be first processed at the second processing element, the second condition being that the second attribute is to be first processed at the third processing element; and reconfigure the first processing element, when the first and second conditions are met, to transmit: a third output stream to the second processing element, the tuples of the third output stream having only the first attribute, and a fourth output stream to the third processing element, the tuples of the fourth output stream having only the second attribute.