XJoin: A Reactively-Scheduled Pipelined Join Operator

Wide-area distribution raises significant performance problems for traditional query processing techniques as data access becomes less predictable due to link congestion, load imbalances, and temporary outages. Pipelined query execution is a promising approach to coping with unpredictability in such environments as it allows scheduling to adjust to the arrival properties of the data. We have developed a non-blocking join operator, called XJoin, which has a small memory footprint, allowing many such operators to be active in parallel. XJoin is optimized to produce initial results quickly and can hide intermittent delays in data arrival by reactively scheduling background processing. We show that XJoin is an effective solution for providing fast query responses to users even in the presence of slow and bursty remote sources. 1 Wide-Area Query Processing The explosive growth of the Internet and the World Wide Web has made tremendous amounts of data available on-line. Emerging standards s...

• Type: Journal
• Year: 2000
• Where: DEBU
• Authors: Tolga Urhan, Michael J. Franklin
• Keywords: DEBU 2000, Query Processing, Remote Sources, Traditional Query Processing