Yunjun Gao is a professor at the College of Computer Science, Zhejiang University, China. His research interests include database and big data management. He has published more than 90 papers in several leading international journals and conferences including TODS, VLDBJ, TKDE, SIGMOD, VLDB, ICDE, and SIGIR. He is a member of the ACM and the IEEE, and a senior member of the CCF. He was an awardee of the NSFC Excellent Young Scholars Program in 2015, the SIGMOD 2015 Best Paper Nomination, one of the ICDE 2015 Best Papers, the First Prize of the MOE Science and Technology Progress (2016), and the First Prize of the Zhejiang Province Science and Technology (2011). Qing Liu received his M.S. degree in computer science from Zhejiang University, China, in 2013, and his B.S. degree in software engineering from Zhejiang Normal University, China, in 2010. He completed his Ph.D. degree at the College of Computer Science, Zhejiang University in June 2017 and is currently pursuing postdoctoral research at Hong Kong Baptist University. His research interests include spatial databases and database usability. He has published more than 10 papers in several leading international journals and conferences including VLDBJ, TKDE, VLDB, and ICDE.