1. Pervasive Query Processing @ HKUST Qiong Luo Hong Kong University of Science & Technology http://www.ust.hk

2. HKUST • American-style, Hong Kong flavored research university • ~40 CS faculty members, mainly in AI, DB, graphics & vision, networking, and theory • Six DB professors: Dik Lee, Hongjun Lu, Fred Lochovsky, Wilfred Ng, Dimitris Papadias, and me. • ~20 DB graduate students, mostly PhD http://www.cs.ust.hk, http://www.cs.ust.hk/db Qiong Luo @ CIDR 2005

3. Pervasive Query Processing • My goal • To enable query processing anywhere, anytime • My practice • Modern PCs: cache-conscious query processing • Internet: Web proxies, browsers, search engines • Sensor networks: emulation, benchmarking • Pervasive computing: device operations • … Pieces of query processors to serve in network applications Qiong Luo @ CIDR 2005

4. Cactus • Cache-conscious automata for XML filtering [ICDE05] • Observations • Filtering systems operate around automata. • Automata state transitions are random accesses. • Cache stalls occupy 50-60% filtering time. • Our work • Modeled the filtering process analytically • Proposed an automata organization technique • Evaluated the model and the technique empirically Model accuracy 85-90%, cache performance up 75-90%, overall 20-47% Qiong Luo @ CIDR 2005

5. Summary • Aorta in pervasive computing • Cactus for cache-consciousness • Epoch in web caching proxies • Meadows for sensor networks • Ollas in browsing and searching • VMNet for sensor networks • WinyDB for PDAs in sensor nets Comments welcome at http://www.cs.ust.hk/catalac Qiong Luo @ CIDR 2005