Implementation of spatial joins on mobile devices

Abstract

AbstractPDAs, cellular phones and other mobile devices are now capable of supporting complex data manipulation operations. Here we focus on ad-hoc spatial joins of datasets residing in multiple non-cooperative servers. Assuming that there is no mediator available, the spatial joins must be evaluated on the mobile device. Contrary to common applications which consider the cost at the server side, our main issue is the minimization of the transferred data while meeting the resource constraints of the device. We start by developing a basic partitioning and pruning algorithm, where optimization is interleaved with query execution. Then, we present a family of sophisticated algorithms, which estimate the data distribution before deciding the physical operator independently for each partition. Our experiments with a simulator and a prototype implementation on a wireless PDA, suggest that our methods outperform the competitors in terms of efficiency and applicability.