Communication-efficient implementation of range-joins in sensor networks

In this article, we consider energy-efficient implementation of the SQL join operation in sensor databases, when the join selection condition is a range predicate. Apart from two simple approaches, we propose distributed hash-join and index-join algorithms for implementation of range-join operations in sensor networks. Through extensive simulations, we show that hash-join as well as index-join approaches significantly outperform the simple approaches, even for moderately sized networks. Our experiments also reveal that although both approach scale well, the index-join algorithm performs better than the hash-join algorithm especially in large sensor networks.