Using snapshot query fidelity to adapt continuous query execution

This paper explores the fidelity of queries issued in pervasive computing networks. A query’s fidelity, or how well its results reflect the state of the environment, can be significantly impacted by dynamics that occur during its distributed execution. We focus on continuous queries that can be built out of sequences of consecutive snapshot queries and show how the fidelity of snapshots can be used to determine the fidelity of continuous queries. This simple notion of continuous query fidelity can be used to adapt query processing to impact quality and cost tradeoffs given the current state of the environment. © 2012 Elsevier B.V. All rights reserved.