Database theory and algorithms; data security and privacy; parallel and distributed algorithms; sampling; data summarization; data streams; data structures; external memory algorithms; computational geometry.
Exploiting the rich interdependence between theory and practice is the
main theme of my research. I always strive to design algorithms with nice
theoretical guarantees that also work well in practice. I like simple
algorithms with nontrivial and elegant analyses. I like theories that
bring insights to how things should be done in practice (this includes
New book with Graham Cormode: Small Summaries for Big Data
Some of my algorithms have been implemented in the following system prototypes:
- SparkSQL+: Next-generation query planning over Spark using generalized hypertree decompositions (GHD), worst-case optimal join (WCOJ) algorithms, and conjunctive queries with comparisons (CQC).
- SecYan: Two-party secure query processing based on the secure Yannakakis algorithm.
- CROWN and Cquirrel: Continuous query processing / change propogation in Flink.
- XDB: Online aggregation for PostgreSQL based on the wander join algorithm.
I belong to both the Theoretical Computer Science
group and the Database group at HKUST.
My research has been supported by Hong Kong RGC, Alibaba, Huawei, Microsoft, and Google.
Students and Postdocs
- Wei Dong (PhD, since Fall 2018; HK PhD Fellowship)
- Qiyao Luo (PhD, since Fall 2019)
- Juanru Fang (PhD, since Fall 2020; HK PhD Fellowship)
- Yuting Liang (PhD, since Fall 2020)
- Dajun Sun (PhD, since Fall 2021; HK PhD Fellowship)
- Bingnan Chen (MPhil, since Fall 2021)
- Zijun Chen (PhD, since Fall 2022; HK PhD Fellowship)
- Binyang Dai (PhD, since Fall 2022)
Former students and postdocs:
- Qichen Wang (PhD, 2022; now Research Assistant Professor at HKBU)
- Yuan Qiu (PhD 2022, HK PhD Fellowship; now at ByteDance)
- Yilei Wang (PhD, 2022; now at Alibaba DAMO Academy)
- Ziyue Huang (PhD 2022; now at Tencent)
- Xiao Hu (PhD 2019; Visiting Faculty Scholar at Google Research → Assistant Professor at the University of Waterloo)
- Yu Chen (PhD 2019; now at Alibaba)
- Bin Wu (PhD 2017; now at Alibaba DAMO Academy)
- Di Chen (PhD 2017, HK PhD Fellowship; co-advised with Mordecai Golin; now at Virtu Financial, Singapore)
- Han Xu (PhD 2016, HK PhD Fellowship; co-advised with Yunhao Liu; now at Huawei)
- Ge Luo (PhD 2016; now at DataYes)
- Lu Wang (PhD 2015; now at Google Switzerland)
- Xiaoyu Ji (PhD 2015, HK PhD Fellowship; co-advised with Yunhao Liu; now Associate Professor at Zhejiang University)
- Longfei Shangguan (PhD 2015; co-advised with Yunhao Liu; now Assistant Professor at the University of Pittsburgh)
- Zengfeng Huang (PhD 2013; now Associate Professor at Fudan University)
- Zhewei Wei (PhD 2012; now Professor at Renmin University)
- Qin Zhang (PhD 2011; co-advised with Mordecai Golin; now Associate Professor at Indiana University Bloomington)
- Haoqian Zhang (MPhil 2019; now PhD student at EPFL)
- Junhong Cao (MPhil 2019; now at AutoX)
- Serafeim Papadias (MPhil 2018; now PhD student at TU Berlin)
- Dexter Lee (MPhil 2018)
- Wai Ming Tai (MPhil 2015; now postdoc at University of Chicago)
- Hao Liu (MPhil 2014; now Assistant Professor at HKUST-GZ)
- Ching-Hin Lau (MPhil 2009)
- Wenqi Zhu (MPhil 2008; first employment: Morgan Stanley)
- Konstantinos Tsakalidis (Postdoc 2012 ~ 2013; now Lecturer at University of Liverpool)
- ACM SIGMOD Best Paper Award, 2016, 2022.
- ACM SIGMOD Best Paper Honorable Mention, 2022.
- ACM PODS Test-of-Time Award, 2022.
- ACM Distinguished Member, 2021.
- Best Teaching Award, MSc Program in Big Data Technology, 2017, 2020.
- ACM SIGMOD Research Highlight Award, 2016, 2022.
- ACM SIGMOD Best Demonstration Award, 2015.
HKUST School of Engineering Young Investigator Research Award, 2012.
- Google Faculty Research Award, 2010.
- Outstanding Ph.D. Dissertation Award, Department of Computer Science, Duke University, August, 2006.
- Top-grade Scholarship, Tsinghua University, 2001.
- Silver Medal, International Olympiad in Informatics (IOI), 1997.
COMP 2711: Discrete Mathematical Tools for Computer Science (17S, 19S, 20S, 21S, 22S)
COMP 3711: Design and Analysis of Algorithms (08F, 09S, 09F, 11F, 12F, 14F, 15S, 15F, 16S)
COMP 3721: Theory of Computation (11S, 12S, 13S)
COMP 5711: Advanced Algorithms (14F, 15F, 16F, 17F, 18F, 19F, 20F, 21F)
COMP 5713: Computational Geometry (10S)
MSBD 5003: Big Data Computing (17S, 17F, 18S, 18F, 19S, 19F, 20F, 21F)
COMP 6311D: Hot Topics on Big Data: Algorithms, Analytics and Applications (13F)
COMP 670S: Data Stream Algorithms (10F)
COMP 670R: Hashing (09F)
COMP 670Q: I/O-Efficient Algorithms and Data Structures (08S)
Email: user name in the email@example.com
Phone: +852-2358 8770
Fax: +852-2358 1477