Traditional Database Management Systems are built on the concept of persistent data sets that are stored reliably in stable storage and queried/updated several times throughout their lifetime. For several emerging application domains, however, data arrives and needs to be processed on a continuous (24x7) basis, and they need processing algorithms and systems that work over continuous data streams. This book is the first in-depth treatment of this important 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.