Byron CHOI (Koon Kau) in (Traditional Chinese and in Pinyin)


Associate Head (Teaching and Learning)

Member of Database Research Group

Programme Director of BSc in Computer Science (JS2510)

Department of Computer Science (Map)
Faculty of Science
, Hong Kong Baptist University

Office: Room 628

David C Lam Building (DLB628)

Hong Kong Baptist University

Kowloon Tong, Hong Kong

Tel: (+852) 3411 7638

Email:  choi at / bchoi at


SCOPUS: author profile   HKBU scholars: profile

Google scholar profile   DBLP entry

Semantic scholar profile


PhD Graduates | Research Interests | Publications | Grants | Hiring

General Information:

I obtained my Ph.D and MSE degrees in Computer and Information Science from the University of Pennsylvania in 2006 and 2001, respectively. I received my Bachelor of Engineering degree (with first-class honours) in Computer Engineering from the Hong Kong University of Science and Technology (HKUST). I was awarded the IEEE (Hong Kong Section) prize in 1999. Before joining the Hong Kong Baptist University, I was an Assistant Professor at School of Computer Engineering / Nanyang Technological University (NTU) for three years between 2005 and 2008. I was a research associate at the University of Edinburgh in 2005 and a summer student intern for the Galax project at AT&T Labs Florham Park. I also visited the HKUST theoretical computer science group in 2003.

I am a member of the Database Research Group at HKBU. I hold memberships with several professional associations including ACM, IEEE, IEEE Computer Society and IEEE Technical Committee of Data Engineering (TCDE). Since September 2021, I have been serving as the ACM SIGMOD information co-director. I have been recognized with several distinctions throughout my career. For example, I was the director of a Croucher Foundation Advanced Study Institute (ASI) titled "Frontiers in Big Data Graph Research" 2015. I have also served as a reviewer for the French Agence Nationale de Recherche (ANR) 2022, the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) 2022, and the Austrian Science Fund (FWF) 2014. I served as a supervisor of Hong Kong Scholars Program (香江學者計劃) 2020.

I have received several awards recognizing my contributions to research, teaching and service. For instance, I was awarded a distinguished program committee (PC) member from ACM SIGMOD 2023 and 2021, respectively, and the best reviewers award from ACM CIKM 2021. I received the distinguished reviewer award from PVLDB 2019. I was the recipient of the HKBU President's Award for Outstanding Performance in Individual Teaching 2022 and the HKBU President's Award for Outstanding Young Researcher 2016, the Department's Best Teaching Award in AY2020-2021 and AY2014-2015, Best Service Award in AY2019-2020 and AY2017-2018, and Best Research Award in AY2013-2014.

Always looking for strong applicants for Postdocs, PhD students, and research assistants:

  • Strong PhD applicants may contact me directly for Hong Kong PhD Fellowship Scheme (HKPFS).
  • Applicants should possess a strong background in (but not limited to) mathematics, algorithms and programming. Priority will be given to those with experience in graph data management or securities. The postdocs and research assistant positions are immediately available for one year and extensible for multiple years based on performance and availability of funds. In terms of research topics, the recent ones can be observed from my selected publications here. Specific examples of possible research topics are available on the following pages: Topic 1 and Topic 2. Our experience on providing secure subgraph query services can be found here. The general information of database research at HKBU can be found here.

Research Interests (w. bibtex) (Selected Publications):

PhD Graduates:

  • Guozhong Li, 2021. (First appointment: Postdoc at HKBU)
  • Jiaxin Jiang, 2020. (Appointment after a Postdoc at HKBU: Research Fellow at National University of Singapore, Singapore)
  • Peipei Yi, 2018. (First appointment: Data Scientist, Machine Intelligence Center, Lenovo, Hong Kong SAR)
  • Zhe Fan, 2015. (First appointment: Big Data Analyst Engineer at Huawei, Shenzhen, China)
  • Yun Peng, 2013. (First appointment: Research Fellow at Nanyang Technological University, Singapore)

General Research Funds (GRF) in the capacity of Principal Investigator (PI):

  • Querying Large Networks of Cryptocurrencies (HKBU12203123, 2023-2024, on-going)
  • Semantic Indexing for Keyword Search on Graphs (HKBU12201119, 2020-2022, completed)
  • Exploring the Structural Critical Entities in Big Attributed Graphs (HKBU12201518, 2019-2021, transferred from Dr. Zhiwei Zhang, completed)
  • Privacy-preserving Linear Algebra Framework for Graph Query Algorithms for Massive Networks (HKBU12232716, 2017-2019, completed)
  • Exploratory Search on Graph Databases through Subgraph Query Feedback (HKBU12201315, 2016-2018, completed)
  • Adaptive Filtering for Efficient Subgraph Isomorphism in Graph Databases (HKBU210510, 2011-2012, completed)
  • Optimizations for the View Update Problem with Emerging Applications (HKBU210409, 2010-2011, completed)


  • COMP4057 Distributed and Cloud Computing
  • COMP4035 Database System Implementation

Program Committee (Partial):

  • SIGMOD 2025, 2024, 2023, 2021, and 2020, EDBT 2023 (senior PC), PVLDB 2022-2021, 2019-2018 and 2015, ICDE 2022-2021, CIKM 2021 (senior PC), AAAI 2022, ICDM 2021, PAKDD 2022-2020, ER 2019, 2015, CIKM (tutorial) 2015, WWW (demo) 2014, CloudDb 2014, IEEE Big Data Science and Engineering (BDSE 2014), IEEE BigData Congress 2014-2013, DEXA 2014-2008, IEEE BDDS2013, DASFAA 2013-2011, APWeb/WAIM 2010-2007, SIGMOD IDAR 2008,...

External Reviewer (Partial):

  • VLDB, ICDE, TODS, VLDBJ, TOIS, TKDE, TKDD, DAPD, Journal of Supercomputing, Information Sciences, Information Systems, ER, ...


Selected Publications (full list at DBLP):

  • L. Xu, B. Choi, Y. Peng, J. Xu and S. S. Bhowmick. A Framework for Privacy Preserving Localized Graph Pattern Query Processing. SIGMOD, 2023 (to appear). (bibtex)
  • Y. Peng, B. Choi, T. Chan, J. Yang and J. Xu. Efficient Approximate Nearest Neighbor Search in Multi-dimensional Databases. SIGMOD, 2023 (to appear). (bibtex)
  • J. Jiang, B. Choi, X. Huang, J. Xu and S. S. Bhowmick. DKWS: A Distributed System for Keyword Search on Massive Graphs. TKDE, 2023 (to appear). (bibtex) [pdf]
  • R. Zuo, G. Li, B. Choi, S. S. Bhowmick, D. N-Y. Mah and G. L-H. Wong. SVP-T: A Shape-level Variable-Position Transformer for Multivariate Time Series Classification. AAAI, 2023 (to appear). (bibtex)
  • Y. Peng, B. Choi, T. Chan, and J. Xu. LAN: Learning-based Approximate k-Nearest Neighbor Search in Graph Databases. ICDE, 2022. Pages 2508-2521. (bibtex)
  • G. Li, B. Choi, J. Xu, S. S. Bhowmick, D. N-Y. Mah and G. L-H. Wong. IPS: Instance Profile for Shapelet Discovery for Time Series Classification. ICDE, 2022. Pages 1781-1793.
  • G. Li, B. Choi, J. Xu, S. S. Bhowmick, K-P Chun and G. L-H. Wong. Efficient Shapelet Discovery for Time Series Classification. TKDE 34(3):1149-1163, 2022. [pdf] [Implementation!] [Visualet: a demo at CIKM '20]
  • P. Yi , B. Choi, Z. Zhang, S. S. Bhowmick and J. Xu. GFocus: User Focus-based Graph Query Autocompletion. TKDE 34(4):1788-1802, 2022. [pdf]
  • L. Xu, J. Jiang, B. Choi, J. Xu, and S. S. Bhowmick. Privacy Preserving Strong Simulation Queries on Large Graphs. ICDE, 2021. Pages 1500-1511. [pdf]
  • G. Li, B. Choi, J. Xu, S. S. Bhowmick, K-P Chun and G. L-H. Wong. ShapeNet: A Shapelet-Neural Network Approach for Multivariate Time Series Classification. AAAI, 2021. Pages 8375-8383. [Implementation!][Adopting the triplet loss function for clustering][Poster at J Hepatol 2021;75(2):S727][Urban Climate 2022;41:101034][Energy Reports 2022;8:12886-12904]
  • Y. Peng, B. Choi and J. Xu. Graph Edit Distance Learning via Modeling Optimum Matchings with Constraints. IJCAI, 2021. Pages 1534-1540.
  • J. Jiang, X. Huang, B. Choi, J. Xu, S. S. Bhowmick, and L. Xu. PPKWS: An Efficient Framework for Keyword Search on Public-Private Networks. ICDE 2020, Pages 457-468. [pdf] [Implementation!]
  • J. Jiang, B. Choi, S. S. Bhowmick and J. Xu. A Generic Ontology Framework for Indexing Keyword Search on Massive Graphs. TKDE, 2019. [pdf] [Implementation!]
  • P. Yi, B. Choi, S. S. Bhowmick and J. Xu. AutoG: A Visual Query Autocompletion Framework for Graph Databases. The VLDB Journal 26(3):347-372, 2017. (the demo at VLDB '16) (an extension to support a large graph -- a highlight in Chinese, 2022)
  • S. S. Bhowmick, B. Choi and C. Dyreson. Data-driven Visual Graph Query Interface Construction and Maintenance: Challenges and Opportunities [Vision]. PVLDB 9(13): 1505-1508, 2016.
  • Y. Peng, B. Choi, B. He, S. Zhou, R. Xu and X. Yu. VColor: A Practical Vertex-cut Based Approach for Coloring Large Graphs. ICDE 2016, Pages 97-108.
  • J. Jiang, P. Yi, B. Choi, Z. Zhang and X. Yu. Privacy-Preserving Reachability Query Services for Massive Networks. CIKM 2016, Pages 145-154.
  • Z. Fan, B. Choi, J. Xu and S. S. Bhowmick. Asymmetric Structure-Preserving Subgraph Query for Large Graphs. ICDE 2015. Pages 339-350. [pdf] [Implementation!]
  • Z. Fan, B. Choi, Q. Chen, J. Xu, H. Hu and S. S. Bhowmick. Structure-Preserving Subgraph Query Services. TKDE 27(8): 2275-2290 (2015). [pdf]
  • Y. Peng, Z. Fan, B. Choi, J. Xu and S. S. Bhowmick. Authenticated Subgraph Similarity Search in Outsourced Graph Databases. TKDE 27(7): 1838-1860 (2015). [pdf]
  • D. Wu, B. Choi, J. Xu and C. S. Jensen. Authentication of Moving Top-k Spatial Keyword Queries. TKDE 27(4):922-935 (2015). [pdf]
  • Z. Fan, Y. Peng, B. Choi, J. Xu and S. S. Bhowmick. Towards Efficient Authenticated Subgraph Query Service in Outsourced Graph Databases. TSC 7(4):696-713, 2014. [pdf]
  • Y. Peng, B. Choi, J. Xu, H. Hu and S. S. Bhowmick. Side-Effect Estimation: A Filtering Approach to the View Update Problem. TKDE 26(9):2307-2322 (2014). [pdf]
  • J. Deng, B. Choi, J. Xu, H. Hu and S. S. Bhowmick. Incremental Maintenance of the Minimum Bisimulation of Cyclic Graphs. TKDE 25(11): 2536-2550 (2013). [pdf]
  • S. S. Bhowmick, B. Choi and S. Zhou. VOGUE: Towards a Visual Interaction-aware Graph Query Processing Framework. CIDR 2013.
  • L. Song, Y. Peng, B. Choi, J. Xu and B. He. Spectral Decomposition for Optimal Graph Index Prediction. PAKDD 2013. Pages 187-200.
  • Y. Peng, B. Choi and J. Xu. Selectivity Estimation of Twig Queries on Cyclic Graphs. ICDE 2011. Pages 960-971.
  • H. Hu, C. Ren, J. Xu and B. Choi. Processing Private Queries over Untrusted Data Cloud through Privacy Homomorphism. ICDE 2011. Pages 601-612.
  • L. Zhu, A. Sun and B. Choi. Detecting Spam-Blogs from Blog Search Results. IPM 2011 47(2): 246-262.
  • B. Choi, H. Hu, J. Xu, W. Cheung, C. H. Li and J. Liu. Data Engineering in Graph Databases. ISCIS 2010. Pages 127 - 132. (invited paper)
  • R. Bramandia, B. Choi and W-K. Ng. Incremental Maintenance of 2-hop Labeling of Large Graphs. TKDE 22(5): 682-698 (2010).
  • C. Jin, S. S. Bhowmick, X. Xiao, J. Cheng and B. Choi. GBLENDER: Towards Blending Visual Query Formulation and Query Processing in Graph Databases. SIGMOD 2010. Pages 111-122.
  • M. Cheng, B. Choi and W. Cheung. Hiding Emerging Patterns with Local Recoding Generalization. PAKDD 2010. Pages 158 - 170.
  • R. Bramandia, J. Cheng, B. Choi and J. X. Yu. Optimizing Updates of Recursive XML Views of Relations. The VLDB Journal 18(5):1313-1333, 2009.
  • R. Bramandia, B. Choi and W-K. Ng. On Incremental Maintenance of 2-hop Labeling of Graphs. WWW 2008. Pages 845-854. [pdf]
  • B. Choi, G. Cong, W. Fan and S. D. Viglas. Updating Recursive XML Views of Relations. JCST 23(4): 516-537 July 2008.
  • N. Tang, J. X. Yu, M. T. Ozsu, B. Choi and K-F. Wong. Multiple Materialized View Selection for XPath Query Rewriting. ICDE 2008. Pages 873-882.
  • B. He, Q. Luo and B. Choi. Adaptive Index Utilization in Memory-Resident Structural Joins. TKDE 19(6): 772 - 788 (2007).
  • B. Choi, G. Cong, W. Fan and S. D. Viglas. Updating Recursive XML Views of Relations. ICDE 2007. Pages 766 - 775.
  • B. He, Q. Luo and B. Choi. Cache-Conscious Automata for XML Filtering. TKDE 18(12): 1629-1644 (2006).
  • Z. Lin, B. He, and B. Choi. A Quantitative Summary of XML Structures. ER 2006. Pages 228-240. LNCS 4215. [pdf] Springer-Verlag.
  • B. Choi. Document Decomposition for XML Compression: A Heuristic Approach. DASFAA 2006. Pages 202-217. LNCS 3382
  • P. Buneman, B. Choi, W. Fan, R. Hutchison, R. Mann and S. D. Viglas. Vectorizing and Querying Large XML Repositories. ICDE 2005. Pages 261-272. [pdf]
  • B. He, Q. Luo and B. Choi. Cache-Conscious Automata for XML Filtering. ICDE 2005. Pages 878-889. [pdf]
  • P. Bohannon, B. Choi and W. Fan. Incremental Evaluation of Schema-Directed XML Publishing. SIGMOD 2004. Pages 503-514. [pdf]
  • B. Choi, W. Fan, X. Jia, and A. Kasprzyk. A Uniform System for Publishing and Maintaining XML Data. VLDB 2004 (demo). Pages 1301-1304.
  • B. Choi, M. Mahoui and D. Wood. On the Optimality of Holistic Algorithms for Twig Queries. DEXA 2003. Pages 28-37. LNCS 2736. [pdf] Springer-Verlag.
  • M. Fernandez, J. Simeon, B. Choi, A. Marian, G. Sur. Implementing Xquery 1.0: The Galax Experience. VLDB 2003 (demo). Pages 1077-1080.
  • B. Choi. What are Real DTDs Like? WebDB 2002. Pages 43-48. [pdf]

Book and Book Chapter:

  • S. S. Bhowmick and B. Choi. Plug-and-Play Visual Subgraph Query Interfaces. Synthesis Lectures on Data Managemnt, Morgan & Claypool Publishers, ISBN 3031161610, March, 2023. [Amazon Link]

  • S. S. Bhowmick, B. Choi, and C. Li. Human Interaction with Graphs: A Visual Querying Perspective. Synthesis Lectures on Data Management, Morgan & Claypool Publishers, ISBN 9781681733784, Aug 2018. [Book Link] [Amazon Link]

  • R. Chen, X. Weng, B. He, B. Choi and M. Yang. Network Performance Aware Graph Partitioning for Large Graph Processing Systems in the Cloud. Large Scale and Big Data: Processing and Management. S. Sakr and M. M. Gaber (Eds.), to be published by CRC Press, 2013 [an earlier version published in SoCC '12]. [Book Link] [Amazon Link]

Filed U.S. Patents:

Selected Presentations:

  • B. Choi. Vectorising and Querying large XML Repositories: Can XML query language be as effective as SQL? Informatics Jamboree 2004 Poster Competition at University of Edinburgh.
  • P. Buneman and B. Choi. Vectorising and Querying XML. National e-Science Institute, Edinburgh. April, May 2004.
  • B. Choi, M. Mahoui and D. Wood. On the Optimality of the Holistic Twig Join Algorithm. DIMACS Working Group on Streaming Data II. March 2003.  (abstract)

Technical Reports:

  • B. Choi, M. Fernandez and J. Simeon. The XQuery Formal Semantics: A Foundation for Implementation and Optimization. Technical Report MS-CIS-02-25, University of Pennsylvania, 2002.
  • B. Choi, M. Mahoui and D. Wood. The Optimality of Holistic Algorithms for XPath. 2003. [pdf]