Methods for processing streaming data records are provided that include facilities for defining and naming multiple input and output data streams using relational processing definitions and abstractions similar to those found in relational database management systems (RDBMS) and embodied as a set of communicating stream processing nodes. The result is a Distributed Data Stream Management System (DDSMS) which is also a kind of Relational Data Stream Management System (RDSMS). The former comprises a set of Relational Data Stream Management System (RDSMS) nodes, whereas the latter might contain only a single RDSMS node.