A Proof Procedure for Data Dependencies
Journal of the ACM (JACM)
Incomplete Information in Relational Databases
Journal of the ACM (JACM)
On conjunctive queries containing inequalities
Journal of the ACM (JACM)
The complexity of querying indefinite data about linearly ordered domains
PODS '92 Proceedings of the eleventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Partial information based integrity constraint checking
Partial information based integrity constraint checking
Chasing constrained tuple-generating dependencies
PODS '96 Proceedings of the fifteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Answering queries using limited external query processors (extended abstract)
PODS '96 Proceedings of the fifteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Theoretical Computer Science - Special issue: principles and practice of constraint programming
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Logical approaches to incomplete information: a survey
Logics for databases and information systems
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
EXPRESS: a data EXtraction, Processing, and Restructuring System
ACM Transactions on Database Systems (TODS)
Horn clauses and database dependencies
Journal of the ACM (JACM)
Constraint-generating dependencies
Journal of Computer and System Sciences
Problem of Incomplete Information in Relational Databases
Problem of Incomplete Information in Relational Databases
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Reformulation of XML Queries and Constraints
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Schema Mapping as Query Discovery
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
On the Maintenance of Implication Integrity Constraints
DDEXA '93 Proceedings of the 4th International Conference on Database and Expert Systems Applications
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Locally consistent transformations and query answering in data exchange
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange: getting to the core
ACM Transactions on Database Systems (TODS) - Special Issue: SIGMOD/PODS 2003
XML data exchange: consistency and query answering
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Schema mappings, data exchange, and metadata management
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Computing cores for data exchange: new algorithms and practical solutions
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange: on the complexity of answering queries with inequalities
Information Processing Letters
Data exchange: semantics and query answering
Theoretical Computer Science - Database theory
The complexity of data exchange
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange: computing cores in polynomial time
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange and incomplete information
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Rewriting queries using views in the presence of arithmetic comparisons
Theoretical Computer Science
VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
ICDT'07 Proceedings of the 11th international conference on Database Theory
Answering aggregate queries in data exchange
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange: query answering for incomplete data sources
Proceedings of the 3rd international conference on Scalable information systems
Query languages for data exchange: beyond unions of conjunctive queries
Proceedings of the 12th International Conference on Database Theory
The recovery of a schema mapping: Bringing exchanged data back
ACM Transactions on Database Systems (TODS)
Composition with target constraints
Proceedings of the 13th International Conference on Database Theory
Managing lineage and uncertainty under a data exchange setting
SUM'10 Proceedings of the 4th international conference on Scalable uncertainty management
Conjunctive queries determinacy and rewriting
Proceedings of the 14th International Conference on Database Theory
Tractable XML data exchange via relations
Proceedings of the 20th ACM international conference on Information and knowledge management
Datalog as a query language for data exchange systems
Datalog'10 Proceedings of the First international conference on Datalog Reloaded
Data exchange with arithmetic operations
Proceedings of the 16th International Conference on Extending Database Technology
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Data exchange is the problem of transforming data structured under a schema (called source) into data structured under a different schema (called target). The emphasis of data exchange is to materialize a target instance (called solution) that satisfies the relationship between the schemas. Universal solutions were shown to be the most suitable solutions, mainly because they can be used to answer conjunctive queries posed over the target schema. Trying to extend this result to more expressive query languages fails, even if we only add inequalities (≠) to conjunctive queries. In this work we study data exchange in the presence of general arithmetic comparisons (, ≥, =, ≠): (a) We consider queries posed over the target schema that belong to the class of unions of conjunctive queries with arithmetic comparisons (in short CQACs). (b) We exploit arithmetic comparisons to define more expressive data exchange settings, called DEAC settings. In particular, DEAC settings consist of constraints that involve arithmetic comparisons. For that, two new classes of dependencies (tgd-ACs and acgds) are introduced, to capture the need of arithmetic comparisons in source-to-target and target constraints. We show that in DEAC settings the existence of solution problem is in NP. We define a novel chase procedure called AC-chase which is a tree and we prove that it produces a universal solution (appropriately defined to deal with arithmetic comparisons). We show that the new concept of universal solution is the right tool for query answering in the case of unions of CQACs. The complexity of computing certain answers for unions of CQACs is shown to be coNP-complete. Moreover, we identify polynomial cases for a) computing a universal solution and b) computing certain answers. For that, we introduce the succinct AC-chase which is a sequence instead of a tree, but its result is not necessarily a solution. We identify cases where succinct AC-chase returns indeed a universal solution and we investigate the syntactic conditions of the query under which query answering takes polynomial time. We show that the latter is feasible even in cases where the result of chase is not a universal solution.