A Proof Procedure for Data Dependencies
Journal of the ACM (JACM)
Incomplete Information in Relational Databases
Journal of the ACM (JACM)
Logical approaches to incomplete information: a survey
Logics for databases and information systems
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
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
Incomplete information and dependencies in relational databases
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
Schema Mapping as Query Discovery
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
Efficient query reformulation in peer data management systems
SIGMOD '04 Proceedings of the 2004 ACM SIGMOD international conference on Management of data
Schema mediation for large-scale semantic data sharing
The VLDB Journal — The International Journal on Very Large Data Bases
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
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Clio grows up: from research prototype to industrial tool
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
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 and incomplete information
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
ULDBs: databases with uncertainty and lineage
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
SPIDER: a schema mapPIng DEbuggeR
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
OLAP over uncertain and imprecise data
The VLDB Journal — The International Journal on Very Large Data Bases
VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
MARS: a system for publishing XML from mixed and redundant storage
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
Data exchange in the presence of arithmetic comparisons
EDBT '08 Proceedings of the 11th international conference on Extending database technology: Advances in database technology
Answering aggregate queries in data exchange
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query answering in peer-to-peer data exchange systems
EDBT'04 Proceedings of the 2004 international conference on Current Trends in Database Technology
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
Reverse data exchange: Coping with nulls
ACM Transactions on Database Systems (TODS)
Data exchange beyond complete data
Proceedings of the thirtieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Data exchange beyond complete data
Journal of the ACM (JACM)
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Data exchange is the problem of transforming data structured under a schema, called the source schema, into data structured under another schema, called the target schema. Existing work on data exchange considers settings where the source instance does not contain incomplete information. In this paper we study semantics and address algorithmic issues for data exchange settings where the source instance may contain incomplete data. We investigate the query answering problem in such data exchange settings. First we give two different meaningful semantics to certain answers: One via the certain answers in the corresponding complete data exchange problems and the other via the set of all solutions of the corresponding complete data exchange problems. We use the chase to compute a universal instance which is materialized over the target schema and is used to compute the certain answers to unions of conjunctive queries. We prove that computing certain answers (under both semantics) for unions of conjunctive queries can be done in polynomial time when the schema mapping contains constraints that consist of a weakly acyclic set of tuple-generating dependencies and equality-generating dependencies.