A parallel execution method for minimizing distributed queryresponse time

Performance studies show that traditional semi-join processing methods are sometimes inefficient because of the storage and processing overhead. To remedy this problem, a new semi-join processing method, called one-shot semi-join execution is proposed. This method allows parallel generation of all the semi-join projections, parallel transmission of all the semi-join projections, and parallel execution of all the semi-joins. The authors apply this method to optimize the response time for processing distributed queries. A response time model is established, which considers both data transmission time and local processing time. Based on this model, an efficient query processing algorithm is developed and analyzed