Smos: a Memory-resident Object Store by Yong Yuan a Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Computer Science University of Rhode Island

1997 ii ABSTRACT In a complex real-time environment, there is often a large amount of temporal data that needs to be promptly collected and made available for processing. To support time constrained access to this data, real-time databases are needed in order to provide predictable transaction time. However, the time constraints can be very tight, requiring a very high database performance level that a conventional database system usually cannot provide. In this thesis, we present a solution for the need of high-performance databases through the design of a memory-resident object repository called SMOS (Shared Memory Object Store). SMOS features an unique client-only architecture in which the server processes and their communications with the clients are eliminated through System V shared memory support. By providing an object model that fully utilizes the type system of the database application programming language, we alternatively unified multiple address spaces into a single address space in SMOS and thus eliminated object moving and format translations. Further performance gain in SMOS was achieved by relaxing some of the transaction ACID properties that are unnecessary in a high speed real-time environment.