Selectivity Evaluation in Distributed Database Query Operations: Static vs Dynamic Techniques
نویسندگان
چکیده
In distributed database query optimization, one of the main factors affecting the performance of an execution strategy is the intermediate fragment sizes produced during the execution of the sub query operations. This paper analyses static vs. dynamic calculation for selectivity of intermediate relations generated in query processing. A Dynamic model for selectivity evaluation (DSET) has been proposed to simulate sub-query allocation and cost optimization for a distributed database query processing environment. Experiments have shown that dynamic evaluation of selectivity factor of sub query operation has significantly reduced the total query cost than its static estimation.
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