Data-stream Query Optimization Across System Boundaries

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The working hypothesis of this sub-project remains that decentralized data-stream processing has its benefit, because it reduces data transmission from the mobile nodes to the ground nodes, among the ground nodes, and from the ground nodes to the central node. The requirements of the biologists are now available as queries in formal language and in machine-processible form. These queries can already be evaluated, but only on the central node and on artifical data. Further data streams will lead to new queries with additional information for the biologists and with the option of decentralized execution. This is extended with status messages from the various nodes to allow for system monitoring. It will be used for the recognition of critical system states, for the assessment of reconfiguration options, and for the initiation of reconfiguration actions. The latter can mean setting a few parameters (e.g. the sampling rate of a sensor), but also the deployment of code from the ground nodes to the mobile nodes (e.g. operators for the pre-aggregation of sensor data).