Basser Seminar Series

Keyword Search in Relational Database

Dr. Wei Wang
School of Computer Science and Engineering, The University of New South Wales

Wednesday 23 May 2007, 4-5 pm

School of IT Building, Lecture Theatre 123, Level 1


With the increasing amount of text data stored in relational databases, there is a demand for RDBMS to support keyword queries over text data. As a search result is often assembled from multiple relational tables, traditional IR-style ranking and query evaluation methods cannot be applied directly.

This talk is mainly based on our recent SIGMOD paper which proposes solutions to addressing the effectiveness and the efficiency issues of answering top-k keyword query in relational database systems. We propose a new ranking formula by adapting existing IR techniques based on a natural notion of virtual document. Compared with previous approaches, our new ranking method is simple yet effective, and agrees with human perceptions. We also study efficient query processing methods for the new ranking method, and propose algorithms that have minimal accesses to the database. We have conducted extensive experiments on large-scale real databases using two popular RDBMSs. The experimental results demonstrate significant improvement to the alternative approaches in terms of retrieval effectiveness and efficiency.

Speaker's biography

Dr. Wei Wang is a Lecturer in the School of Computer Science and Engineering, The University of New South Wales, Australia. His current research interests include integration of database and information retrieval technologies, query processing and optimization for XML data, data warehousing and mining, and spatial databases. He has published over twenty research papers in these areas in major international journal (TODS) and conferences (SIGMOD, VLDB, ICDE).