Principles of database and knowledge-base systems, Vol. I
Principles of database and knowledge-base systems, Vol. I
Journal of Computer and System Sciences
Circumscribing DATALOG: expressive power and complexity
Theoretical Computer Science
The OPL optimization programming language
The OPL optimization programming language
LOCAL ++: A C++ framework for local search algorithms
Software—Practice & Experience
Local Search in Combinatorial Optimization
Local Search in Combinatorial Optimization
Tabu Search
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Extending and implementing the stable model semantics
Artificial Intelligence
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Constraints
A Survey of Automated Timetabling
Artificial Intelligence Review
Combining Relational Algebra, SQL, and Constraint Programming
FroCoS '02 Proceedings of the 4th International Workshop on Frontiers of Combining Systems
Scheduling Aircraft Landings--The Static Case
Transportation Science
The complexity of relational query languages (Extended Abstract)
STOC '82 Proceedings of the fourteenth annual ACM symposium on Theory of computing
EasyLocal++: an object-oriented framework for the flexible design of local-search algorithms
Software—Practice & Experience
Existential second-order logic over graphs: Charting the tractability frontier
Journal of the ACM (JACM)
The DLV system for knowledge representation and reasoning
ACM Transactions on Computational Logic (TOCL)
Solving SQL Constraints by Incremental Translation to SAT
IEA/AIE '08 Proceedings of the 21st international conference on Industrial, Engineering and Other Applications of Applied Intelligent Systems: New Frontiers in Applied Artificial Intelligence
A SQL database system for solving constraints
Proceedings of the 2nd PhD workshop on Information and knowledge management
A Case Study in Engineering SQL Constraint Database Systems (Extended Abstract)
ICLP '08 Proceedings of the 24th International Conference on Logic Programming
Constraint processing in relational database systems: from theory to implementation
Proceedings of the 2010 ACM Symposium on Applied Computing
Proceedings of the 27th Annual ACM Symposium on Applied Computing
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The goal of this paper is to provide a strong integration between constraint modelling and relational DBMSs. To this end we propose extensions of standard query languages such as relational algebra and SQL, by adding constraint modelling capabilities to them. In particular, we propose non-deterministic extensions of both languages, which are specially suited for combinatorial problems. Non-determinism is introduced by means of a guessing operator, which declares a set of relations to have an arbitrary extension. This new operator results in languages with higher expressive power, able to express all problems in the complexity class NP. Some syntactical restrictions which make data complexity polynomial are shown. The effectiveness of both extensions is demonstrated by means of several examples. The current implementation, written in Java using local search techniques, is described.