Building an efficient preference XML query processor

ABSTRACT

Today user-centered information acquisition over collections of complex XML documents is increasingly in demand. To this end, preferences have become an important paradigm enabling users to express individual interests and delivering personalized information. As the structure of XML documents plays a major part in retrieval, users often have specific preferences about the structure. For evaluation a query has to be unfolded into an entire set of queries filling the structure with more or less preferred values. Since such structure expansions typically contain redundancies, it is important to identify and simplify necessary expansion queries for effective evaluation. To address these issues, we developed a preference query optimizer that not only determines an optimal set of expansion queries, but also preserves the specific ordering induced by the user preferences with respect to Pareto optimality.

REFERENCES

• 1: Sihem Amer-Yahia , SungRan Cho , Laks V. S. Lakshmanan , Divesh Srivastava, Minimization of tree pattern queries, Proceedings of the 2001 ACM SIGMOD international conference on Management of data, p.497-508, May 21-24, 2001, Santa Barbara, California, United States
• 2: SungRan Cho , Wolf-Tilo Balke, Order-preserving optimization of twig queries with structural preferences, Proceedings of the 2008 international symposium on Database engineering & applications, September 10-12, 2008, Coimbra, Portugal [doi>10.1145/1451940.1451971]
• 3: Jan Chomicki, Preference formulas in relational queries, ACM Transactions on Database Systems (TODS), v.28 n.4, p.427-466, December 2003 [doi>10.1145/958942.958946]
• 4: Werner Kießling, Foundations of preferences in database systems, Proceedings of the 28th international conference on Very Large Data Bases, p.311-322, August 20-23, 2002, Hong Kong, China

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.3 INFORMATION STORAGE AND RETRIEVAL
      H.3.3 Information Search and Retrieval
          Subjects: Query formulation

Additional Classification:
  H. Information Systems
  H.3 INFORMATION STORAGE AND RETRIEVAL
      H.3.3 Information Search and Retrieval
          Subjects: Retrieval models; Search process

General Terms:
Algorithms, Performance

Keywords:
XML databases, personalization, preference-based retrieval