The TSIMMIS Approach to Mediation: Data Models and Languages
Journal of Intelligent Information Systems - Special issue: next generation information technologies and systems
Answering recursive queries using views
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
A layered architecture for querying dynamic Web content
SIGMOD '99 Proceedings of the 1999 ACM SIGMOD international conference on Management of data
Navigational plans for data integration
AAAI '99/IAAI '99 Proceedings of the sixteenth national conference on Artificial intelligence and the eleventh Innovative applications of artificial intelligence conference innovative applications of artificial intelligence
Information integration using logical views
Theoretical Computer Science - Special issue on the 6th International Conference on Database Theory—ICDT '97
Conjunctive query containment revisited
Theoretical Computer Science - Special issue on the 6th International Conference on Database Theory—ICDT '97
Theory of answering queries using views
ACM SIGMOD Record
Accelerated focused crawling through online relevance feedback
Proceedings of the 11th international conference on World Wide Web
Principles of Database and Knowledge-Base Systems: Volume II: The New Technologies
Principles of Database and Knowledge-Base Systems: Volume II: The New Technologies
A Scalable Algorithm for Answering Queries Using Views
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
Querying Heterogeneous Information Sources Using Source Descriptions
VLDB '96 Proceedings of the 22th International Conference on Very Large Data Bases
A survey of approaches to automatic schema matching
The VLDB Journal — The International Journal on Very Large Data Bases
Statistical schema matching across web query interfaces
Proceedings of the 2003 ACM SIGMOD international conference on Management of data
The Piazza peer data management project
ACM SIGMOD Record
An adaptive crawler for locating hidden-Web entry points
Proceedings of the 16th international conference on World Wide Web
Web table taxonomy and formalization
ACM SIGMOD Record
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To provide access to distributed and heterogeneous sources, information integration systems have traditionally relied on the availability of a mediated schema, along with mappings between this schema and the schema of the information sources. Queries posed to the mediated schema are then reformulated in terms of the source schemas. On the Web, where sources are plentiful, autonomous and extremely volatile, a system based on the existence of a pre-defined mediated schema and mapping information presents several drawbacks. Notably, the cost of keeping the mappings up to date as new sources are found or existing sources change can be prohibitively high. In this paper, we propose a new querying mechanism for integrating a large number of sources that requires neither a mediated schema nor source mappings. In the absence of a mediated schema, the user formulates queries based on what she expects to find. These queries are rewritten using a best-effort approach: the rewriting component compares a user query against the source schemas and produces a set of rewritings based on the matches found. We demonstrate the feasibility of this approach by providing a query interface for integrating hundreds of (real) structured Web information sources. We also discuss experimental results which indicate that our query rewriting algorithm can be effective.