Using remote joins for the processing of distributed mobile queries

The query processing in a mobile computing environment involves join processing among different sites which include static servers and mobile computers. In this paper, we first present some unique features of a mobile environment, and then, in light of these features, devise query processing methods for both join and query processing. Remote mobile joins are said to be effectual if they are, when interleaved into a join sequence, able to reduce the data transmission cost required for distributed mobile query processing. It can be verified that the total data transmission cost of the processing in a distributed mobile query can be reduced by algorithms designed by using effectual remote joins. A simulator is developed to evaluate the performance of the devised algorithms. Our results show that the approach of interleaving the processing of distributed mobile queries with effectual remote mobile joins is not only efficient but also effective in reducing the total data transmission cost required to process distributed mobile queries.