Asynchronous Data Retrieval from an Object-Oriented Database
We present an object-oriented semantic database model which, similar to other object-oriented systems, combines the virtues of four concepts: the functional data model, a property inheritance hierarchy, abstract data types and message-driven computation. The main emphasis is on the last of these four concepts. We describe generic procedures that permit queries to be processed in a purely message-driven manner. A database is represented as a network of nodes and directed arcs, in which each node is a logical processing element, capable of communicating with other nodes by exchanging messages. This eliminates the need for shared memory and for centralized control during query processing. Hence, the model is suitable for implementation on a multiprocessor computer architecture, consisting of large numbers of loosely coupled processing elements.
KeywordsRequest Message Virtual Node Abstract Data Type Role Relationship External Schema
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- [Agha85]Agha. G.A. Actors: A Model of Concurrent Computation In Distributed Systems. Tech. Rep. No. 844. MIT Artificial Intelligence Lab., MIT, Cambridge, Mass..Google Scholar
- [Arvind78]Arvind, Gostelow, K.P. and Plouffe, W. An Asynchronous Programming and Computing Machine. Tech. Rep. No. 114a. Univ. of CA., Irvine, Dept. of Info. and Comp. Sci..Google Scholar
- [Borgida87]Borgida, A. Conceptual Modeling of Information Systems. In On Knowledge Base Management Systems, Brodie, M.L. and Mylopoulos, J., Ed., Springer-Verlag, 1987.Google Scholar
- [Brodie80]Proceedings of the Workshop on Data Abstraction, Databases and Conceptual Modelling, Brodie, M.L. and Zilles, S.N, Ed., Sponsored by the Nat’l. Bureau of Standards, ACM SIGART, SIGMOD and SIGPLAN, Pingree Park, Colordo, 1980.Google Scholar
- [Findler79]ASSOCIATIVE NETWORKS Representation and Use of Knowledge by Computers, Findler, N., Ed., Academic Press, 1979.Google Scholar
- [Hull86]Hull, R. and King R. Semantic Database Modeling: Survey, Applications, and research Issues. Tech. Rep. No. TR-86-201. U.S.C., Comp. Sci. Dept..Google Scholar
- [Mcleod78]McLeod, D. A Semantic Data Base Model and its Associated User Interface. Rep. No. MIT/LCS/TR-214. Lab. for Computer Sci., MIT, Cambridge.Google Scholar
- [Stefik86]Stefik, M. and Bobrow D.G. Object-Oriented Programming: Themes and Variations. The AI Magazine 6,4 (Jan., 1986), 40–62.Google Scholar