The Tangram stream query processing system

Tangram, an environment for modeling which is under development at UCLA, is discussed. One of the driving concepts behind Tangram has been the combination of large-scale data access and data reduction with a powerful programming environment. The Tangram environment is based on PROLOG, extending it with a number of features, including process management, distributed database access, and generalized stream processing. The authors describe the Tangram stream processor, the part of the Tangram environment performing query processing on large streams of data. The paradigm of transducers on streams is used throughout this system, providing a database flow computation capability.<>