The efficiency of common subexpression identification is critical to the performance of multiple-queryprocessing. In this paper, we develop a multigraph for representing and facilitating the processing of multiple qu...
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The efficiency of common subexpression identification is critical to the performance of multiple-queryprocessing. In this paper, we develop a multigraph for representing and facilitating the processing of multiple queries. In addition to the traditional multiple-queryprocessing approaches in exploiting common subexpressions for identical and subsumption cases, the proposed multigraph processing also covers the overlap case. A performance study shows the viability of this technique when compared to an earlier multigraph approach.
This paper presents some applications of partial evaluation method to a query optimization in deductive database. A Horn clause transformation is used for the partial evaluation of a query in an intensional database, ...
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This paper presents some applications of partial evaluation method to a query optimization in deductive database. A Horn clause transformation is used for the partial evaluation of a query in an intensional database, and its application to multiple query processing is discussed. Three strategies are presented for the compatible case, ordered case and crossed case. In each case, partial evaluation is used to preprocess the intensional database in order to obtain subqueries which direct access to an extensional database.
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