Zhiyuan Chen

Department of Computer Sciences
Cornell University
4110 Upson Hall
Ithaca, NY 14853
zhychen@cs.cornell.edu,
Office: (607)255-9124; fax: (607)255-4428

I have finished my Ph.D. in August 2002 and joined Microsoft Research. Please visit my new homepage.

My advisor is Professor Johannes Gehrke. My main area of interest is database systems, especially in database compression, physical database design, E-Commerce, XML, and data warehousing.

In my dissertation research, I have explored new directions of improving performance of database systems given current trends of hardware development and the requirement of new applications. My research addresses the following three areas: (i) the development of  compressed database systems, (ii) techniques that use succinct summary structures to give quick and accurate estimation of the result size of queries on string or hierarchical data (e.g., XML), and (iii) a general approach for automatic physical database design. See a list of selected publications below or a full list.

I received my B.S. in Computer Science at Fudan University, China in August 1995 and M.S. in Computer Science at Fudan University, China in August 1997. 

Selected Publications:

• Zhiyuan Chen, Flip Korn, Nick Koudas, S. Muthukrishnan: Generalized Substring Selectivity Estimation. Journal of Computer and System Sciences, to appear.
  

• Zhiyuan Chen, Johannes Gehrke, Flip Korn: Query Optimization in Compressed Database Systems. In proceedings of the ACM SIGMOD International Conference on Management of Data, May 21 - 24, 2001, Santa Barbara, California, USA. (SIGMOD'2001) Abstract, pdf, ps, slides. (Acceptance rate: 15%.)

• Zhiyuan Chen, H.V. Jagadish, Flip Korn, Nick Koudas, S., Muthukrishnan, Raymond Ng, and Divesh Srivastava: Counting Twig Matches in a Tree. In proceedings of The 17h International Conference on Data Engineering, April 2-6, 2001, Heidelberg, Germany, 595-604. (ICDE' 2001) Abstract, ps. (Acceptance rate: 17%.)
  
  

• Zhiyuan Chen, Flip Korn, Nick Koudas, S. Muthukrishnan: Selectivity Estimation for Boolean Queries. In proceedings of the Nineteenth ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, May 15-17, 2000, Dallas, Texas, USA, 216-225. (PODS' 2000). Abstract, pdf, slides. Also invited to the the Journal of Computer and System Sciences (JCSS). (Acceptance rate: 22%.)
  
  
  

• Zhiyuan Chen and Praveen Seshadri: An Algebraic Compression Framework for Query Results. In proceedings of the 16th International Conference on Data Engineering, 28 February - 3 March, 2000, San Diego, California, USA, 177-188. (ICDE' 2000) Abstract, pdf, ps, Slides. Preliminary version: Zhiyuan Chen and Praveen Seshadri: A compression framework for query results. Compute Science Dept, Cornell University, Technical Report TR98-1720. (Acceptance rate: 14%.)