Date Added: Jan 2011
Sensor networks are being widely deployed for measurement, detection and surveillance applications. In these new applications, users issue long-running queries over a combination of stored data and sensor data. Most existing applications rely on a centralized system for collecting sensor data. These systems lack flexibility because data is extracted in a predefined way; also, they do not scale to a large number of devices because large volumes of raw data are transferred regardless of the queries that are submitted. In the new concept of sensor database system, queries dictate which data is extracted from the sensors. In this paper, the authors define a model for sensor databases. Stored data are represented as relations while sensor data are represented as time series.