Database Systems for Advanced Applications : 17th International Conference, DASFAA 2012, International Workshops: FlashDB, ITEMS, SNSM, SIM3, DQDI, Busan, South Korea, April 15-18, 2012, Proceedings - Hwanjo Yu, Ge Yu, Wynne Hsu, Yang-Sae Moon, Rainer Unland, Jaesoo Yoo ((Lecture Notes in Computer Science))