Implementing a relational database by means of specialzed hardware
ACM Transactions on Database Systems (TODS)
Introduction to a system for distributed databases (SDD-1)
ACM Transactions on Database Systems (TODS)
Performance evaluation of a relational associative processor
ACM Transactions on Database Systems (TODS)
Using Semi-Joins to Solve Relational Queries
Journal of the ACM (JACM)
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
The Architecture of SM3: A Dynamically Partitionable Multicomputer System
IEEE Transactions on Computers
Query Optimization in Database Systems
ACM Computing Surveys (CSUR)
Range nesting: a fast method to evaluate quantified queries
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
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Semi-join is a relational operator that decreases the cost of processing queries involving binary operations. This is accomplished by initially selecting the data relevant to answer the queries and thereby reducing the size of the operand relations. This paper presents and analyzes algorithms for computing semi-joins in a multiprocessor database machine. First, an architecture model of a multiprocessor system is described. The model incorporates 1-0, CPU and messages transmission cost parameters to enable the evaluation of these algorithms in terms of their execution costs. Then two equi-semi-join algorithms are presented and compared and one inequi-semi-join algorithm is proposed. The execution cost of these algorithms are generally lineary proportional to the size of the operand and result relations and inversely proportional to the number of processors. Then, the method by joining two relations and the method by joining their semi-joins are compared. Finally it is shown that the method using semi-joins is generally better.