Refreshments at 2:30, Talk from 3:00-4:00 Analytical and Experimental Evaluation of Stream Based Joins

Continuous queries over data streams have gained popularity as the breadth of possible applications, ranging from network monitoring to online pattern discovery, have increased. Joining of streams is a fundamental issue that must be resolved to enable complex queries over multiple streams. However, as streams can represent potentially infinite data, it is infeasible to have full join evaluations as is the case with traditional databases. Joins in a stream environment are thus evaluated not over entire streams, but on specific windows defined on the streams. In this talk, we present windowed implementations of the traditional nested loops and hash join algorithms. The talk will be followed by a brief presentation on ongoing work on sensors by Michael Librodo.