A Proof Procedure for Data Dependencies
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ACM Transactions on Database Systems (TODS)
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
Data integration: a theoretical perspective
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On the decidability and complexity of query answering over inconsistent and incomplete databases
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Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Data integration under integrity constraints
Information Systems - Special issue: The 14th international conference on advanced information systems engineering (CAiSE*02)
Elements Of Finite Model Theory (Texts in Theoretical Computer Science. An Eatcs Series)
Elements Of Finite Model Theory (Texts in Theoretical Computer Science. An Eatcs Series)
Data exchange: getting to the core
ACM Transactions on Database Systems (TODS) - Special Issue: SIGMOD/PODS 2003
Data exchange: semantics and query answering
Theoretical Computer Science - Database theory
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Tractable Reasoning and Efficient Query Answering in Description Logics: The DL-Lite Family
Journal of Automated Reasoning
Efficient core computation in data exchange
Journal of the ACM (JACM)
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Generalized schema-mappings: from termination to tractability
Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
A general datalog-based framework for tractable query answering over ontologies
Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query rewriting and answering under constraints in data integration systems
IJCAI'03 Proceedings of the 18th international joint conference on Artificial intelligence
On chase termination beyond stratification
Proceedings of the VLDB Endowment
Finite model reasoning in DL-lite
ESWC'08 Proceedings of the 5th European semantic web conference on The semantic web: research and applications
Static analysis of schema-mappings ensuring oblivious termination
Proceedings of the 13th International Conference on Database Theory
LICS '10 Proceedings of the 2010 25th Annual IEEE Symposium on Logic in Computer Science
Chase termination: a constraints rewriting approach
Proceedings of the VLDB Endowment
Advanced processing for ontological queries
Proceedings of the VLDB Endowment
ACM Transactions on Database Systems (TODS)
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A universal model of a database D and a set Σ of integrity constraints is a database that extends D, satisfies Σ, and is most general in the sense that it contains sound and complete information. Universal models have a number of applications including answering conjunctive queries, and deciding containment of conjunctive queries, with respect to databases with integrity constraints. Furthermore, they are used in slightly modified form as solutions in data exchange. In general, it is undecidable whether a database possesses a universal model, but in the past few years researchers identified various settings where this problem is decidable, and even efficiently solvable. This paper focuses on computing universal models under finite sets of guarded TGDs, non-conflicting keys, and negative constraints. Such constraints generalize inclusion dependencies, and were recently shown to be expressive enough to capture certain members of the DL-Lite family of description logics. The main result is an algorithm that, given a database without null values and a finite set Σ of such constraints, decides whether there is a universal model, and if so, outputs such a model. If Σ is fixed, the algorithm runs in polynomial time. The algorithm can be extended to cope with databases containing nulls; however, in this case, polynomial running time can be guaranteed only for databases with bounded block size.