Queries over Sensor Networks Sam Madden UC Berkeley Database Seminar October 5, 2001

Sensor Environment Recent Research at UCB, MIT, UCLA focused on hardware, systems, and networking issues in sensors Database researchers conspicuously absent Lots of data challenges Streaming data Intermittent connectivity Power / Bandwidth Limitations No Storage Very limited code space, RAM

Fjords Sensors push data Want to combine that data with pre-existing tables Traffic Example Fjords abstract push/pull into connection between operators Bracket Model (Graefe) Revisted

Continuous Queries Sensor environments involve lots of queries over same set of sensors E.g. Building information system, environmental / scientific monitoring Opportunity for Continuous Queries Improve on existing approaches with adaptivity, support for streams

Aggregation in Sensor Networks Push aggregates down into sensor networks to reduce data, power load on sensors Take advantage of network topology See Next Week’s DB Seminar