Pankaj K. Agarwal Junyi Xie Jun Yang 0001 Hai Yu Scalable Continuous Query Processing by Tracking Hotspots. 31-42 2006 conf/vldb/2006 VLDB http://www.vldb.org/conf/2006/p31-agarwal.pdf db/conf/vldb/vldb2006.html#AgarwalXYY06