On the optimal nesting order for computing N-relational joins
ACM Transactions on Database Systems (TODS)
Join processing in database systems with large main memories
ACM Transactions on Database Systems (TODS)
Optimization of large join queries
SIGMOD '88 Proceedings of the 1988 ACM SIGMOD international conference on Management of data
Heuristic algorithms for distributed query processing
DPDS '88 Proceedings of the first international symposium on Databases in parallel and distributed systems
Optimization of large join queries: combining heuristics and combinatorial techniques
SIGMOD '89 Proceedings of the 1989 ACM SIGMOD international conference on Management of data
Tradeoffs in processing complex join queries via hashing in multiprocessor database machines
Proceedings of the sixteenth international conference on Very large databases
Encapsulation of parallelism in the Volcano query processing system
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
Randomized algorithms for optimizing large join queries
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
Multi-join on parallel processors
DPDS '90 Proceedings of the second international symposium on Databases in parallel and distributed systems
Parallel algorithms for the execution of relational database operations
ACM Transactions on Database Systems (TODS)
Access path selection in a relational database management system
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
Hash-Based and Index-Based Join Algorithms for Cube and Ring Connected Multicomputers
IEEE Transactions on Knowledge and Data Engineering
Prototyping Bubba, A Highly Parallel Database System
IEEE Transactions on Knowledge and Data Engineering
GAMMA - A High Performance Dataflow Database Machine
VLDB '86 Proceedings of the 12th International Conference on Very Large Data Bases
Optimization of Nonrecursive Queries
VLDB '86 Proceedings of the 12th International Conference on Very Large Data Bases
VLDB '88 Proceedings of the 14th International Conference on Very Large Data Bases
IEEE Transactions on Knowledge and Data Engineering
Parallelizing query optimization
Proceedings of the VLDB Endowment
Genetic programming in database query optimization
GECCO '96 Proceedings of the 1st annual conference on Genetic and evolutionary computation
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Optimizing large join queries that consist of many joins has been recognized as NP-hard. Most of the previous work focuses on a uniprocessor environment. In a multiprocessor, the location of each join adds another dimension to the complexity of the problem. In this paper, we examine the feasibility of exploiting the inherent parallelism in optimizing large join queries on a hypercube multiprocessor. This includes using the multiprocessor not only to answer the large join query but also to optimize it. We propose an algorithm to estimate the cost of a parallel large join plan. Three heuristics are provided for generating an initial solution, which is further optimized by an iterative local-improvement method. The entire process of parallel query optimization and execution is simulated on an Intel iPSC/2 hypercube machine. Our experimental results show that the performance of each heuristic depends on the characteristics of the query.