ABSTRACT
B Functions are filters/transformers from one kind of data stream to another.
B Data is processed from upstream on a need basis from downstream.
T the problem of processing data that comes intothe application continuously and may not even have an end. The same issues are seen in processing data whose size is known, but larger than the available memory. The style establishes a flow of data from upstream (data sources) to downstream (data sinks), with processing units along the way. The data is let to flow through the stream only when the sinks need it. At any point in time, the only data present in the stream is the one needed to produce whatever piece of data the sinks need, therefore avoiding the problems raised by too much data at a time.
