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Research Topic - XML Query Evaluation and
Estimation
1) With the fast-growing use of XML data on the Web,
optimizing XML queries has become one of the most active and exciting
research areas. Developments in query processing and selectivity
estimations of XML data are among the major issues since they determine
data access methods and the best possible execution plans for complex
XML queries.
This research aims to develop efficient approaches
for query evaluation and selectivity estimations of XML queries. We
examine how path information in XML data can be utilized to speed up
structural join, which is the core operation in XML query processing.
The proposed solution comprises of a path-based node labeling scheme and
a path join algorithm. The path-based approach is also efficient for an
important class of XML queries involving structural join with
not-predicates.
We also design several methods for XML selectivity
estimations. These include a compact statistical method, a
histogram-based method for skewed XML data, and a path-based method for
estimating the selectivity of XML queries with and without order-based
axes,
2) Some publications
Hanyu Li, Mong Li Lee, Wynne Hsu, Ling Li. A
Path-Based Approach for Efficient Structural Join with Not-Predicates,
accepted in 12th International Conference on Database Systems
for Advanced Applications, Bangkok, Thailand, April 2007.
Ling Li, Mong Li Lee, Wynne Hsu.
Rewriting Queries for XML Integration Systems, in 17th
International Conference on Database and Expert Systems Applications (DEXA),
Krakow, Poland, September 2006.
Hanyu Li, Mong Li Lee, Wynne Hsu,
Gao Cong. An Estimation System for XPath Expressions, in IEEE
22nd International Conference on Data Engineering (ICDE), Atlanta,
Georgia, April 2006.
Hanyu Li, Mong Li Lee, Wynne Hsu.
A Path-Based Labeling Scheme for Efficient Structural Join, in
3rd International XML Database Symposium (XSym), in conjunction with
VLDB, Trondheim, Norway, August 2005.
Hanyu Li, Mong Li Lee, Wynne Hsu.
A Histogram-Based Selectivity Estimator for Skewed XML Data, in
16th International Conference on Database and Expert Systems
Applications (DEXA), Copenhagen, Denmark, August 2005.
3) Names of the
Faculty Members in the research area
Lee Mong Li and Wynne Hsu |
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