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. We say that query Q is expressible by the program P if it is equivalent to some expansion of P. Q is supported by P if it has an equivalent rewriting using some finite set of 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.

• Type: Conference
• Year: 2009
• Where: ICDT
• Authors: Bogdan Cautis, Alin Deutsch, Nicola Onose
• Keywords: Application Queries, Conjunctive Queries, Database, ICDT 2009, Source Accepts Families