An optimization of queries in distributed database systems

Journal Article · Sun Jun 01 00:00:00 EDT 1986 · J. Parallel Distrib. Comput.; (United States)

DOI:https://doi.org/10.1016/0743-7315(86)90001-8· OSTI ID:6471978

Chung, C W; Irani, K B

This paper addresses the processing of a query in distributed database systems using a sequence of semijoins. The objective is to minimize the intersite data traffic incurred by a distributed query. A method is developed which accurately and efficiently estimates the size of an intermediate result of a query. This method provides the basis of the query optimization algorithm. Since the distributed query optimization problem is known to be intractable, a heuristic algorithm is developed to determine a low-cost sequence of semijoins. The cost comparison with an existing algorithm is provided. The complexity of the main features of the algorithm is analytically derived. The scheduling time for sequences of semijoins is measured for example queries using the PASCAL program which implements the algorithm.

• Research Organization: Computer Science Dept., General Motors Research Labs., Warren, MI 48090
• OSTI ID: 6471978
• Journal Information: J. Parallel Distrib. Comput.; (United States), Journal Name: J. Parallel Distrib. Comput.; (United States) Vol. 3:2; ISSN JPDCE
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990210* -- Supercomputers-- (1987-1989)
ACCURACY
ALGORITHMS
COMMUNICATIONS
COST
DATA BASE MANAGEMENT
DATA PROCESSING
DATA TRANSMISSION
DISTRIBUTED DATA PROCESSING
INFORMATION RETRIEVAL
MANAGEMENT
MATHEMATICAL LOGIC
OPTIMIZATION
PASCAL
PROCESSING
PROGRAMMING LANGUAGES
TASK SCHEDULING
TIME MEASUREMENT