Extracting result schema based on query instances in the Deep Web
Tóm tắt
Deep Web sources contain a large of high-quality and query-related structured date. One of the challenges in the Deep Web is extracting result schemas of Deep Web sources. To address this challenge, this paper describes a novel approach that extracts both result data and the result schema of a Web database. The approach first models the query interface of a Deep Web source and fills in it with a specifically query instance. Then the result pages of the Deep Web sources are formatted in the tree structure to retrieve subtrees that contain elements of the query instance. Next, result schema of the Deep Web source is extracted by matching the subtree’ nodes with the query instance, in which, a two-phase schema extraction method is adopted for obtaining more accurate result schema. Finally, experiments on real Deep Web sources show the utility of our approach, which provides a high precision and recall.
Tài liệu tham khảo
Ghanem T M, Aref W G. Database Deepen the Web[J]. Journal of Web Technologies, 2004, 37(1):116–117.
Chakrabarti S, Berg M, Dom B. Focused Crawling: A New Approach to Topic Specific Web Resource Discovery[C] //Proc of 8th www Conference. Toronto: ACM Press, 1999: 1623–1640.
Raghavan S, Garcia-Molina H. Crawling the Hidden Web [C]// Proc of 27th very Large DataBase Conference. Roma: VLDB Press, 2001: 129–138.
Zhang Z, He B, Chang K. Understanding Web Query Interfaces: Best-Effort Parsing with Hidden Syntax[C]// Proc of SIGMOD 2004. Paris: ACM Press, 2004:107–118.
Ipeirotis P G, Gravano L, Sahami M. Probe, Count, and Classify: Categorizing HiddenWeb Databases[C]//Proc of SIGMOD 2001. Santa Babara: ACM Press, 2001:67–78.
Chang K, He B, Li C. Structured Databases on the Web: Observations and Implications[J]. SIGMOD Record, 2004, 33(3):61–70.
Zhang Z, He B, Chang K C. MetaQuerier: Querying Structured Web Sources On-the-Fly[C]//Proceeding of SIGMOD 2005. Baltimore: ACM Press, 2005: 927–929.
He B, Chang K C. Statistical Schema Matching across Web Query Interfaces[C]//Proceedings of the 22nd International Conference on Management of Data (SIGMOD). San Diego: ACM Press, 2003:217–228.
Wu W, Doan A, Yu C. Merging Interface Schemas on the Deep Web Via Clustering Aggregation[C]//Proc of 5th ICDM. New Orleans: IEEE Press, 2005: 801–804.
Wang J, Wen J. Instance-Based Schema Matching for Web Databases by Domain-Specific Query Probing [C]//Proc of the 30th very Large DataBase Conference. Toronto: VLDB Press, 2004:408–419.
Wu W, Doan A, Yu C. Web-IQ: Learning from the Web to Match Deep-Web Query Interfaces[C]//Proc of 22nd ICDE. Atlanta: IEEE Press, 2006: 679–690.
Wang J, Lochovsky F. Data Extraction and Label Assignment for Web Databases[C]// Proc of www 2003. Budapast: ACM Press, 2003:187.
Caverlee J, Liu L. QA-Pagelet: Data Preparation Techniques for Large-Scale Data Analysis of the Deep Web[J]. Transactions on Knowledge and Data Engineering, 2005, 17(9):1247–1262.
Liu W, Meng X, Meng W. Vision-Based Web Data Records Extraction[C]//Proc of the SIGMOD Workshop on WebDB 2006. Chicago: ACM Press, 2006.