OM: A Tunable Framework for Optimizing Continuous Queries Over Data Streams
Continuous Query (CQ) is an important class of queries in Data Stream Management Systems. While much work has been done on algorithms for processing CQs, less attention has been paid to the issue of optimizing such queries. In this paper, the authors first argue that parameters such as output rate and main memory utilization are important cost objectives for CQ performance, than disk I/O. They propose a novel framework, called OM to optimize the memory utilization and output rate of CQs. The authors' technique monitors input stream and query characteristics, and switches plans only at certain boundary conditions.