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