A Proof Procedure for Data Dependencies
Journal of the ACM (JACM)
Foundations of logic programming; (2nd extended ed.)
Foundations of logic programming; (2nd extended ed.)
Monotone monadic SNP and constraint satisfaction
STOC '93 Proceedings of the twenty-fifth annual ACM symposium on Theory of computing
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
A restricted second order logic for finite structures
Information and Computation
Horn clauses and database dependencies
Journal of the ACM (JACM)
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Data Exchange: Semantics and Query Answering
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 Logical Modeling of ETL Processes
CAiSE '02 Proceedings of the 14th International Conference on Advanced Information Systems Engineering
Data exchange: getting to the core
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Piazza: data management infrastructure for semantic web applications
WWW '03 Proceedings of the 12th international conference on World Wide Web
VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
Composing mappings among data sources
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
Efficient query reformulation in peer data management systems
SIGMOD '04 Proceedings of the 2004 ACM SIGMOD international conference on Management of data
Preserving mapping consistency under schema changes
The VLDB Journal — The International Journal on Very Large Data Bases
Kanata: adaptation and evolution in data sharing systems
ACM SIGMOD Record
Representing and Querying Data Transformations
ICDE '05 Proceedings of the 21st International Conference on Data Engineering
Logical foundations of peer-to-peer data integration
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
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
Composition of mappings given by embedded dependencies
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Supporting executable mappings in model management
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
Clio grows up: from research prototype to industrial tool
Proceedings of the 2005 ACM SIGMOD international conference on Management of data
Semantic adaptation of schema mappings when schemas evolve
VLDB '05 Proceedings of the 31st international conference on Very large data bases
HePToX: marrying XML and heterogeneity in your P2P databases
VLDB '05 Proceedings of the 31st international conference on Very large data bases
Composing schema mappings: Second-order dependencies to the rescue
ACM Transactions on Database Systems (TODS) - Special Issue: SIGMOD/PODS 2004
The complexity of data exchange
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
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
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
XML Mapping technology: making connections in an XML-centric world
IBM Systems Journal
Data integration: the teenage years
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Implementing mapping composition
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Nested mappings: schema mapping reloaded
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Composition of mappings given by embedded dependencies
ACM Transactions on Database Systems (TODS)
Information retrieval and machine learning for probabilistic schema matching
Information Processing and Management: an International Journal
Using the uni-level description (ULD) to support data-model interoperability
Data & Knowledge Engineering - Special issue: ER 2003
Quasi-inverses of schema mappings
ACM Transactions on Database Systems (TODS)
On the complexity of deriving schema mappings from database instances
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
XML data integration in SixP2P: a theoretical framework
DaMaP '08 Proceedings of the 2008 international workshop on Data management in peer-to-peer systems
Reconciling Inconsistent Data in Probabilistic XML Data Integration
BNCOD '08 Proceedings of the 25th British national conference on Databases: Sharing Data, Information and Knowledge
Query Propagation in a P2P Data Integration System in the Presence of Schema Constraints
Globe '08 Proceedings of the 1st international conference on Data Management in Grid and Peer-to-Peer Systems
Graceful database schema evolution: the PRISM workbench
Proceedings of the VLDB Endowment
A step towards incremental maintenance of the composed schema mapping
Proceedings of the 17th ACM conference on Information and knowledge management
Query languages for data exchange: beyond unions of conjunctive queries
Proceedings of the 12th International Conference on Database Theory
Logical foundations of relational data exchange
ACM SIGMOD Record
Ontology-Based Query Interface in a System for Semantic Integration of XML Data
KES-AMSTA '09 Proceedings of the Third KES International Symposium on Agent and Multi-Agent Systems: Technologies and Applications
Automating database schema evolution in information system upgrades
Proceedings of the 2nd International Workshop on Hot Topics in Software Upgrades
Schema mapping discovery from data instances
Journal of the ACM (JACM)
Managing XML Schema Mappings and Annotations in P2P Data Integration Systems
OTM '09 Proceedings of the Confederated International Workshops and Posters on On the Move to Meaningful Internet Systems: ADI, CAMS, EI2N, ISDE, IWSSA, MONET, OnToContent, ODIS, ORM, OTM Academy, SWWS, SEMELS, Beyond SAWSDL, and COMBEK 2009
Schema mapping and query translation in heterogeneous P2P XML databases
The VLDB Journal — The International Journal on Very Large Data Bases
Querying a super-peer in a schema-based super-peer network
DBISP2P'05/06 Proceedings of the 2005/2006 international conference on Databases, information systems, and peer-to-peer computing
Logic and data exchange: which solutions are "good" solutions?
LOFT'08 Proceedings of the 8th international conference on Logic and the foundations of game and decision theory
Journal of Computer and System Sciences
ICDT'07 Proceedings of the 11th international conference on Database Theory
Three semantics for distributed systems and their relations with alignment composition
ISWC'06 Proceedings of the 5th international conference on The Semantic Web
A framework for query reformulation between knowledge base peers
WAIM '06 Proceedings of the 7th international conference on Advances in Web-Age Information Management
Specifying schema mappings for query reformulation in data integration systems
AWIC'05 Proceedings of the Third international conference on Advances in Web Intelligence
SWDB'04 Proceedings of the Second international conference on Semantic Web and Databases
Reducing the cost of validating mapping compositions by exploiting semantic relationships
ODBASE'06/OTM'06 Proceedings of the 2006 Confederated international conference on On the Move to Meaningful Internet Systems: CoopIS, DOA, GADA, and ODBASE - Volume Part I
sPLMap: a probabilistic approach to schema matching
ECIR'05 Proceedings of the 27th European conference on Advances in Information Retrieval Research
Management of executable schema mappings for XML data exchange
EDBT'06 Proceedings of the 2006 international conference on Current Trends in Database Technology
A calculus for propagating semantic annotations through scientific workflow queries
EDBT'06 Proceedings of the 2006 international conference on Current Trends in Database Technology
Datalog as a query language for data exchange systems
Datalog'10 Proceedings of the First international conference on Datalog Reloaded
Tableaux-based optimization of schema mappings for data integration
Journal of Intelligent Information Systems
Representation systems for data exchange
Proceedings of the 15th International Conference on Database Theory
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A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the target schema). Schema mappings play a key role in numerous areas of database systems, including database design, information integration, and model management. A fundamental problem in this context is composing schema mappings: given two successive schema mappings, derive a schema mapping between the source schema of the first and the target schema of the second that has the same effect as applying successively the two schema mappings.In this paper, we give a rigorous semantics to the composition of schema mappings and investigate the definability and computational complexity of the composition of two schema mappings. We first study the important case of schema mappings in which the specification is given by a finite set of source-to-target tuple-generating dependencies (source-to-target tgds). We show that the composition of a finite set of full source-to-target tgds with a finite set of tgds is always definable by a finite set of source-to-target tgds, but the composition of a finite set of source-to-target tgds with a finite set of full source-to-target tgds may not be definable by any set (finite or infinite) of source-to-target tgds; furthermore, it may not be definable by any formula of least fixed-point logic, and the associated composition query may be NP-complete. After this, we introduce a class of existential second-order formulas with function symbols, which we call second-order tgds, and make a case that they are the "right" language for composing schema mappings. To this effect, we show that the composition of finite sets of source-to-target tgds is always definable by a second-order tgd. Moreover, the composition of second-order tgds is also definable by a second-order tgd. Our second-order tgds allow equalities, even though the "obvious" way to define them does not require equalities. Allowing equalities in second-order tgds turns out to be of the essence, because we show that second-order tgds without equalities are not sufficiently expressive to define even the composition of finite sets of source-to-target tgds. Finally, we show that second-order tgds possess good properties for data exchange. In particular. the chase procedure can be extended to second-order tgds so that it produces polynomial-time computable universal solutions in data exchange settings specified by second-order tgds.