Answering recursive queries using views
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Consistent query answers in inconsistent databases
PODS '99 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
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
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
A Portrait of the Semantic Web in Action
IEEE Intelligent Systems
A Logic Programming Approach to the Integration, Repairing and Querying of Inconsistent Databases
Proceedings of the 17th International Conference on Logic Programming
Data Exchange: Semantics and Query Answering
ICDT '03 Proceedings of the 9th International Conference on Database Theory
A Scalable Algorithm for Answering Queries Using Views
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
Query Rewriting with Symmetric Constraints
FoIKS '02 Proceedings of the Second International Symposium on Foundations of Information and Knowledge Systems
Answering queries using views: A survey
The VLDB Journal — The International Journal on Very Large Data Bases
On the decidability and complexity of query answering over inconsistent and incomplete databases
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data integration under integrity constraints
Information Systems - Special issue: The 14th international conference on advanced information systems engineering (CAiSE*02)
Query rewriting and answering under constraints in data integration systems
IJCAI'03 Proceedings of the 18th international joint conference on Artificial intelligence
Computing certain answers in the presence of dependencies
Information Systems
Query processing under GLAV mappings for relational and graph databases
Proceedings of the VLDB Endowment
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In the Semantic Web, the goal is offering access to information that is distributed over the Internet. Data integration is highly relevant in this context, since it consists in providing a uniform access to a set of data sources, through a unified representation of the data called global schema. Integrity constraints (ICs) are expressed on the global schema in order to better represent the domain of interest, yet such constraints may not be satisfied by the data at the sources. In this paper we address the problem of answering queries posed to a data integration system where the mapping is specified in the so-called GLAV approach, and when tuple-generating dependencies (TGDs) and functional dependencies (FDs) are expressed over the global schema. We extend previous results by first showing that, in the case of TGDs without FDs, known query rewriting techniques can be applied in a more general case, and can take into account also the GLAV mapping in a single rewriting step. Then we introduce FDs with TGDs, identifying a novel class of ICs for which query answering is decidable, and providing a query answering algorithm based on query rewriting also in this case.