Theory of Computing Systems

, Volume 49, Issue 2, pp 367–428

Querying Data Sources that Export Infinite Sets of Views



We study the problem of querying data sources that accept only a limited set of queries, such as sources accessible by Web services which can implement very large (potentially infinite) families of queries. We revisit a classical setting in which the application queries are conjunctive queries and the source accepts families of conjunctive queries specified as the expansions of a (potentially recursive) Datalog program with parameters.

We say that query Q is expressible by the program \(\ensuremath{\mathcal{P}}\) if it is equivalent to some expansion of \(\ensuremath{\mathcal{P}}\). Q is supported by \(\ensuremath{\mathcal{P}}\) if it has an equivalent rewriting using some finite set of \(\ensuremath{\mathcal{P}}\)’s expansions. We present the first study of expressibility and support for sources that satisfy integrity constraints, which is generally the case in practice.


Query rewriting using views Limited query capabilities Integrity constraints Datalog 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Department of Computer ScienceTelecom ParisTechParisFrance
  2. 2.Department of Computer Science and EngineeringUniversity of California, San DiegoLa JollaUSA
  3. 3.Department of Computer ScienceUC IrvineIrvineUSA

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