Issue No. 04 - April (1986 vol. 12)
Masahiro Tsuchiya , TRW Defense Systems Group, Redondo Beach, CA 90278
Michael P. Mariani , TRW Defense Systems Group, Colorado Springs, CO 80916
James D. Brom , TRW Defense Systems Group, Colorado Springs, CO 80916
This paper describes a simple yet effective distributed database model that simulates database usage and buffer management in the distributed data processing environment. The model is table driven such that database access requirements, file location, and other information defining the database environment are set up internally in several tables, and linked lists represent the directory and data blocks. Each database transaction is defined and represented by a transaction flow diagram (TFD) and a sequence of TFD's representing an operational scenario is input to the model. The model “executes” input TFD's by looking up tables, and performs buffer management for directory and file data while logging history and gathering various statistics on database usage and buffer management. The performance data are used for database access overhead measurement, database workload characterization, and buffer allocation. Disk access frequency and response time are used to validate the simulation results. The model has been implemented in Fortran on the VAX 11/780 and has been used for both measuring the given database performance and analyzing sensitivity to design changes. The results have proven that, despite its simplicity, the database model presented is an effective systems engineering tool for the design of distributed databases.
Distributed databases, Data models, Space vehicles, Analytical models, Aerospace electronics, Time factors, transaction flow diagram, Buffer management, directory, disk access, distributed database management, performance
M. Tsuchiya, M. P. Mariani and J. D. Brom, "Distributed database management model and validation," in IEEE Transactions on Software Engineering, vol. 12, no. , pp. 511-520, 1986.