An object flow computer for database applications

In the past two decades, a considerable amount of research exists which use hardware, firmware, and novel architectures to achieve the needed efficiency in implementing database management functions. However, most of the efforts have been directed toward developing database computers for supporting a relatively primitive data model, namely, the relational model. This paper presents the design and performance evaluation of an Object Flow Computer (OFC) for processing data modeled by an Object-oriented Semantic Association Model (OSAM*). The OFC allows high-level semantic constructs as seen by the users of a large data/knowledge base to be processed by hardware directly without many levels of transformations to a low-level data representation. It employs a vertically fragmented data storage structure and a two-phase processing strategy to process queries in order to avoid unnecessary transfer of a large amount of data from secondary storage and among processors. Also, a set of primitive operators is defined for the OFC. Depending on the performance requirement, these operators can be implemented in software or as special-purpose processors in the form of VLSI chips. Based on these primitive operators, a high-level database request can be decomposed and executed in parallel. Finally, the OFC combines a number of known database processing techniques such as query decomposition, pipelining mode of data processing, and data flow control strategy. Together with hardware/firmware support in the form of special-purpose processors, the OFC offers an integrated software/hardware solution to the very large database management problem.