Query Processing and Optimization on the Web

Authors: Ouzzani M.¹; Bouguettaya A.²

Source: Distributed and Parallel Databases, Volume 15, Number 3, May 2004 , pp. 187-218(32)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

Abstract:

The advent of the Internet and the Web and their subsequent ubiquity have brought forth opportunities to connect information sources across all types of boundaries (local, regional, organizational, etc.). Examples of such information sources include databases, XML documents, and other unstructured sources. Uniformly querying those information sources has been extensively investigated. A major challenge relates to query optimization. Indeed, querying multiple information sources scattered on the Web raises several barriers for achieving efficiency. This is due to the characteristics of Web information sources that include volatility, heterogeneity, and autonomy. Those characteristics impede a straightforward application of classical query optimization techniques. They add new dimensions to the optimization problem such as the choice of objective function, selection of relevant information sources, limited query capabilities, and unpredictable events. In this paper, we survey the current research on fundamental problems to efficiently process queries over Web data integration systems. We also outline a classification for optimization techniques and a framework for evaluating them.

Keywords: query optimization; Web; data integration; mediators; databases

Document Type: Research article

DOI: http://dx.doi.org/10.1023/B:DAPD.0000018574.71588.06

Affiliations: 1: Department of Computer Science, Virginia Tech., Email: mourad@vt.edu 2: Department of Computer Science, Virginia Tech., Email: athman@vt.edu

Publication date: 2004-05-01