XML Data Management



XML is emerging as a de facto format of the Internet era for information exchange and system integration. As the distribution and sharing of XML information over the World Wide Web become increasingly important, the needs for flexible and efficient storage, access control and query processing of XML data naturally arise. Our research work contributes to this area in two aspects:

  1. applying database technologies (such as metadata modeling and data warehouse) to integrate Web and Relational data;
  2. developing practical solutions to the problems of XML data access control.

We have developed a metadata driven approach to load XML data into a relational database. One novel part of this work is that the processes of relational schema generation and loading of XML data are all automatic. This technology is expected to make a significant impact on e-business and e-services. A prototype system based on this innovation was implemented and two patents have been filed. For XML access control, a new middleware technique, called QFilter, based on non-deterministic finite automata has been developed to enforce access control policies in an efficient and non-redundant fashion. QFilter filters out all or part of unauthorized requests by query rewriting technique before a XML engine responds to the rewritten queries. Finally, we have developed a new query processing technique for XQuery, called path gluing. The idea is to quickly retrieving data in accordance with individual path expressions of specified query predicates and gluing them to obtain the correct data.

Current Members

bulletWang-Chien Lee


bulletYa-Hui Chang
bulletDongwon Lee
bulletPeng Liu
bulletGail Mitchell
bulletPrasenjit Mitra
bulletElke Rundensteiner


  1. B. Luo, D. Lee, W.-C. Lee, and P. Liu, Deep Set Operators for XQuery, International Workshop on XQuery Implementation, Experience and Perspectives (XIME-P'05), Baltimore, Maryland, May 2005. [pdf]

  2. B. Luo, D. Lee, W.-C. Lee, and P. Liu, QFilter: Fine-Grained Run-Time XML Access Control via NFA-based Query Rewriting, the thirteen ACM International Conference on Information and Knowledge Management (CIKMí04), Washington D.C., Nov. 8-13, 2004, pp. 543-552. (~19% acceptance rate). [pdf]

  3. B. Luo, D. Lee, W.-C. Lee, and P. Liu, A Flexible Framework for Architecting XML Access Control Enforcement Mechanisms, International Workshop on Secure Data Management in a Connected World (SDM'04), Toronto, Canada, August 2004, pp. 141-155. [pdf]

  4. D.W. Lee, W.-C. Lee, and P. Liu, Supporting XML Security Models using Relational Databases: A Vision, the First XML Database Symposium (XSym'03), Berlin, Germany, Sept. 8, 2003, pp. 267-281. Acceptance rate: 27% [pdf]

  5. K. Claypool, X. Zhang, E. Rundensteiner, S. Hong, H. Kuno, W.-C. Lee, and G. Mitchell, Model Management - A Solution to support Multiple Data Models, Their Mappings, and Maintenance, ACM International Conference on SIGMOD, Santa Barbara, CA, May 21-24, 2001, pp. 606. (demonstration paper) [pdf]

  6. X. Zhang, W.-C. Lee, G. Mitchell, and E. Rundensteiner, Clock: Synchronizing Internal Relational Storage with External XML Documents, the eleventh International Workshop on Research Issues in Data Engineering: Document Management (RIDE'01), Heidelberg, Germany, 2001, pp. 111-118. [pdf]

  7. W.-C. Lee, G. Mitchell, and X. Zhang, Integrating XML Data with Relational Databases, IEEE International Workshop on Knowledge Discovery and Data Mining in World Wide Web, Taipei, Taiwan, April 10-13, 2000, pp. F47-F53. [pdf]

  8. S. Heiler, W.-C. Lee, and G. Mitchell, Repository Support for Metadata-based Legacy Migration, IEEE Data Engineering Bulletin, Volume 22, No. 1, March 1999, pp. 37-42. [pdf]


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Last updated: 09/18/05.