Query processing in a system for distributed databases (SDD-1)
ACM Transactions on Database Systems (TODS)
Using Semi-Joins to Solve Relational Queries
Journal of the ACM (JACM)
Approximating block accesses in database organizations
Communications of the ACM
A relational model of data for large shared data banks
Communications of the ACM
An Introduction to Database Systems
An Introduction to Database Systems
The Design and Analysis of Computer Algorithms
The Design and Analysis of Computer Algorithms
A methodology for interpreting tree queries into optimal semi-join expressions
SIGMOD '80 Proceedings of the 1980 ACM SIGMOD international conference on Management of data
The tree property is fundamental for query processing
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
A Heuristic Approach to Distributed Query Processing
VLDB '82 Proceedings of the 8th International Conference on Very Large Data Bases
Properties of acyclic database schemes
STOC '81 Proceedings of the thirteenth annual ACM symposium on Theory of computing
Optimization of join operations in horizontally partitioned database systems
ACM Transactions on Database Systems (TODS)
Set query optimization in distributed database systems
ACM Transactions on Database Systems (TODS)
R* optimizer validation and performance evaluation for local queries
SIGMOD '86 Proceedings of the 1986 ACM SIGMOD international conference on Management of data
Load balancing in a locally distributed DB system
SIGMOD '86 Proceedings of the 1986 ACM SIGMOD international conference on Management of data
Data replicas in distributed information services
ACM Transactions on Database Systems (TODS)
Dynamic query evaluation plans
SIGMOD '89 Proceedings of the 1989 ACM SIGMOD international conference on Management of data
On the effect of join operations on relation sizes
ACM Transactions on Database Systems (TODS)
Optimal Semijoins for Distributed Database Systems
IEEE Transactions on Software Engineering
Proceedings of the 1985 ACM SIGSMALL symposium on Small systems
Simulation of a distributed database system incorporating a routing optimizer
ANSS '85 Proceedings of the 18th annual symposium on Simulation
Outerjoin optimization in multidatabase systems
DPDS '90 Proceedings of the second international symposium on Databases in parallel and distributed systems
Query Optimization in Database Systems
ACM Computing Surveys (CSUR)
An Intelligent Search Method for Query Optimization by Semijoins
IEEE Transactions on Knowledge and Data Engineering
Supporting a Semantic Data Model in a Distributed Database System
VLDB '83 Proceedings of the 9th International Conference on Very Large Data Bases
Optimizing Star Queries in a Distributed Database System
VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
Optimization of Nested Queries in a Distributed Relational Database
VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
R* Optimizer Validation and Performance Evaluation for Distributed Queries
VLDB '86 Proceedings of the 12th International Conference on Very Large Data Bases
File Allocation in Distributed Databases with Interaction between Files
VLDB '83 Proceedings of the 9th International Conference on Very Large Data Bases
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An algorithm is given to process a given query in a fragmented distributed data base environment. Unlike previous algorithms, it has the following desired features.(1) It makes use of redundant relations to reduce communication cost;(2) a copy of each relation referenced by the query is selected so that the set of relations are contained in the minimum number of sites;(3) an efficient algorithm to process fragments is provided;(4) all relations that need not be sent to the assembly site to produce the answer are identified. Thus, unnecessary sending of these relations across sites and processing on these relations, which are common in earlier algorithms, are avoided;(5) useless semi-joins are discarded and "worse" semi-joins are replaced by better ones;(6) a process to estimate the cost and the benefit of a semi-join, based on dynamic execution of semi-joins is introduced. It is expected that the new process is more accurate than earlier estimation process.The algorithm is easy to implement and is operational.