Unlike traditional databases, which are reliable and relatively unchanging, data streams arrive in an uninterrupted flow which must be continuously processed. This timely reference book explores and contrasts the old persistent data set model with today's seamless data stream environment, and proposes algorithms and systems that work over continuous data streams. This is the first in-depth treatment of this evolving topic, covering basic data stream techniques, data stream synopses, mining data streams, advanced data stream computations, and systems and architectures for data stream management systems.