Open Access

Wolf-Tilo Balke, Ulrich Güntzer, Werner Kießling

• Mobile services offering multi-feature query capabilities must meet tough response time requirements to gain customer acceptance. The top-k query model is a popular candidate to implement such services. Focusing on a central server architecture we present a new algorithm called SR-Combine that closely self-adapts itself to particular cost ratios in such environments. SR-Combine optimizes both the object accesses and the query run-times. We perform a series of synthetical benchmarks to verify the superiority of SR-Combine over existing algorithms. In order to assess whether it can meet the stated response time requirements for mobile access, we propose a psychologically founded model. It turns out that for a wide range of practical cases SR-Combine can satisfy these goals. Where this isn't yet the case, we show up ways how to get there systematically. Thus with SR-Combine a breakthrough in real-time capabilities of top-k querying for mobile services is in sight now.