Big Data 9th CCF Conference, BigData 2021, Guangzhou, China, January 8–10, 2022, Revised Selected Papers - Liao, Xiangke; Zhao, Wei; Chen, Enhong; Xiao, Nong; Wang, Li; Gao, Yang; Shi, Yinghuan; Wang, Changdong; Huang, Dan (Springer Singapore, 2022)