Containment and minimization of positive conjunctive queries in OODB's
PODS '92 Proceedings of the eleventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
On the decidability of query containment under constraints
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Conjunctive-query containment and constraint satisfaction
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
The entity-relationship model—toward a unified view of data
ACM Transactions on Database Systems (TODS) - Special issue: papers from the international conference on very large data bases: September 22–24, 1975, Framingham, MA
On the Complexity of Testing Implications of Functional and Join Dependencies
Journal of the ACM (JACM)
A relational model of data for large shared data banks
Communications of the ACM
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Accessing Data Integration Systems through Conceptual Schemas
ER '01 Proceedings of the 20th International Conference on Conceptual Modeling: Conceptual Modeling
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
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
DL-Lite: tractable description logics for ontologies
AAAI'05 Proceedings of the 20th national conference on Artificial intelligence - Volume 2
Containment of conjunctive object meta-queries
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Tractable Query Answering over Conceptual Schemata
ER '09 Proceedings of the 28th International Conference on Conceptual Modeling
Querying incomplete data over extended er schemata
Theory and Practice of Logic Programming
DASFAA'11 Proceedings of the 16th international conference on Database systems for advanced applications: Part II
Query containment in entity SQL
Proceedings of the 2013 ACM SIGMOD International Conference on Management of Data
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Conceptual Modelling plays a fundamental role in database design since Chen's Entity-Relationship (ER) model. In this paper we consider a conceptual model capable of capturing classes of objects with their attributes, relationships among classes, cardinality constraints in the participation of entities to relationships, and is-a relations among both classes and relationships. We provide a formal semantics for such model in terms of predicates and constraints over their extensions. We address the problem of containment of conjunctive queries over a conceptual schema, and we show an algorithm for solving the problem, that achieves better computational complexity than the techniques found in the literature. The results presented here are directly applicable in query answering on incomplete databases, and in data integration under constraints.