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The LLUNATIC data-cleaning framework

Floris Geerts, Giansalvatore Mecca, Paolo Papotti, Donatello Santoro
2013 Proceedings of the VLDB Endowment  
Data-cleaning (or data-repairing) is considered a crucial problem in many database-related tasks. It consists in making a database consistent with respect to a set of given constraints.  ...  We propose a new semantics for repairs, and a chase-based algorithm to compute minimal solutions.  ...  More complex operations are also partially available, but lack the support for constraints. We do allow for forward and backward chasing.  ... 
doi:10.14778/2536360.2536363 fatcat:q7bg5zqnizdrbonmo5bj6dtzra

Minimization of tree pattern queries with constraints

Ding Chen, Chee-Yong Chan
2008 Proceedings of the 2008 ACM SIGMOD international conference on Management of data - SIGMOD '08  
In this paper, we explore the TPQ minimization problem further for a richer class of FBST-constraints that includes not only FT-constraints but also backward and sibling constraints.  ...  , TPQ minimization has been studied for the class of forward and subtype constraints (FT-constraints).  ...  backward and sibling constraints.  ... 
doi:10.1145/1376616.1376678 dblp:conf/sigmod/ChenC08 fatcat:y6wrp6ivrrag3nxzl2eulphy6q

Mapping and cleaning

Floris Geerts, Giansalvatore Mecca, Paolo Papotti, Donatello Santoro
2014 2014 IEEE 30th International Conference on Data Engineering  
Presc(id, pat, npi, cf) Each tgd states a constraint over the target database.  ...  Based on the semantics, we introduce a chase-based algorithm to compute solutions. Appropriate care is devoted to developing a scalable implementation of the chase algorithm.  ...  Notice also that we do not backward-chase tgds, since the only way to backward-chase a tgd like m t1 consists in deleting tuple t x , and there is general consensus that deleting tuples causes unnecessary  ... 
doi:10.1109/icde.2014.6816654 dblp:conf/icde/GeertsMPS14 fatcat:zmlpbegytbcajmem5ulcgtaigu

Rewrite and Conquer: Dealing with Integrity Constraints in Data Integration [chapter]

Andrea Calì, Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini
2013 Seminal Contributions to Information Systems Engineering  
contains the classical key and foreign key constraints, and the mapping between the data sources and the global schema is of the global-as-view type.  ...  The work "Data Integration under Integrity Constraints", published at the CAiSE 2002 Conference, proposes a rewriting technique for answering queries in data integration systems, when the global schema  ...  Hence q r can be unfolded and evaluated by a standard relational database engine.  ... 
doi:10.1007/978-3-642-36926-1_28 fatcat:ldze5kvp4bfhfccyl5moadrdti

Semantic query optimization in the presence of types

Michael Meier, Michael Schmidt, Fang Wei, Georg Lausen
2010 Proceedings of the twenty-ninth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems of data - PODS '10  
cost function), and investigate the complexity of related decision problems.  ...  Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted.  ...  INTRODUCTION Typing is a central component of many practical database systems, including (but not limited to) relational databases, object-oriented database models [25, 35] , typed datalog [42] , and  ... 
doi:10.1145/1807085.1807102 dblp:conf/pods/MeierSWL10 fatcat:s6mfk5rnszdrfnmb5w2vl5ypgi

Semantic query optimization in the presence of types

Michael Meier, Michael Schmidt, Fang Wei, Georg Lausen
2013 Journal of computer and system sciences (Print)  
cost function), and investigate the complexity of related decision problems.  ...  Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted.  ...  INTRODUCTION Typing is a central component of many practical database systems, including (but not limited to) relational databases, object-oriented database models [25, 35] , typed datalog [42] , and  ... 
doi:10.1016/j.jcss.2013.01.010 fatcat:nir7h5ucufgh3eiywkoiwusvta

That's all folks!

Floris Geerts, Giansalvatore Mecca, Paolo Papotti, Donatello Santoro
2014 Proceedings of the VLDB Endowment  
Despite this need, database research has so far investigated mappings and data repairing essentially in isolation.  ...  It is widely recognized that whenever different data sources need to be integrated into a single target database errors and inconsistencies may arise, so that there is a strong need to apply data-cleaning  ...  Data transformation, or data exchange [2] , is the process of translating data coming from one or more relational sources into a single target database.  ... 
doi:10.14778/2733004.2733031 fatcat:r6nxerxanbeihp7updvzv3ks3q

Cooperative update exchange in the Youtopia system

Łucja Kot, Christoph Koch
2009 Proceedings of the VLDB Endowment  
We present a novel change propagation model that combines a deterministic chase with human intervention.  ...  The first is very general and related to classical final-state serializability; the second is more restrictive but highly practical and related to conflict-serializability.  ...  The Youtopia backward chase Unlike a forward chase, a backward chase must eventually terminate, as it cannot delete more tuples than exist in the database initially.  ... 
doi:10.14778/1687627.1687650 fatcat:q42hnpqr4beftarjobqxxsuoga

Cooperative Update Exchange in the Youtopia System [article]

Lucja Kot, Christoph Koch
2009 arXiv   pre-print
We present a novel change propagation model that combines a deterministic chase with human intervention.  ...  The first is very general and related to classical final-state serializability; the second is more restrictive but highly practical and related to conflict-serializability.  ...  The Youtopia backward chase Unlike a forward chase, a backward chase must eventually terminate, as it cannot delete more tuples than exist in the database initially.  ... 
arXiv:0903.5346v1 fatcat:ovleuiigkrgczeupu57amjkxee

Generating Plans from Proofs

Michael Benedikt, Balder Ten Cate, Efthymia Tsamoura
2016 ACM Transactions on Database Systems  
Our method can exploit the integrity constraints to find plans even when there is no direct access to relations appearing in the query.  ...  The database does not allow users to access the Professor and Student table directly, but instead exposes a view Professor where the id attribute is dropped, and a table Student where the advisor's id  ...  Let config ∞ be a (possibly infinite) instance resulting from chasing the canonical database of Q with the constraints of Sch.  ... 
doi:10.1145/2847523 fatcat:szrzwhessvhs5coqcsebtwqeva

Deep Separability of Ontological Constraints [article]

Andrea Calì, Marco Console, Riccardo Frosini
2013 arXiv   pre-print
Commonly adopted database constraints in this field are tuple-generating dependencies (TGDs) and equality-generating dependencies (EGDs).  ...  and the constraints.  ...  The conditions are quite involved and they make use of backward-resolution.  ... 
arXiv:1312.5914v2 fatcat:d4horudoivhsjob4jxrod7zhty

Containment and Minimization of RDF/S Query Patterns [chapter]

Giorgos Serfiotis, Ioanna Koffina, Vassilis Christophides, Val Tannen
2005 Lecture Notes in Computer Science  
., data integration, graphical query generators, caching, etc.) and has been extensively studied for relational, deductive, object, and XML databases.  ...  To this end, we advocate a logic framework for capturing the RDF/S data model and semantics and we employ well-established techniques proposed in the relational context, in particular, the Chase and Backchase  ...  Acknowledgements We would like to thank Alin Deutsch and Nicola Onose for fruitful discussions on relational and XML SQO.  ... 
doi:10.1007/11574620_44 fatcat:hv5f6blgxfbinjvlsy2m4ntk64

On the Termination of the Chase Algorithm [chapter]

Michael Meier
2010 Lecture Notes in Computer Science  
Relational constraints allow the database schema designer to restrict the contents of a database to meaningful data only.  ...  The basic idea of the chase is, given a database instance and a set of constraints as input, to x constraint violations in the database instance.  ... 
doi:10.1007/978-3-642-15918-3_23 fatcat:wsougypcmrhmxm3s6choxxfssm

Ontological Query Answering via Rewriting [chapter]

Georg Gottlob, Giorgio Orsi, Andreas Pieris
2011 Lecture Notes in Computer Science  
Ontological databases extend traditional databases with ontological constraints.  ...  by the constraints.  ...  constraints over the database.  ... 
doi:10.1007/978-3-642-23737-9_1 fatcat:rzowvzmy4rdo5nmxqvi6kbby2m

Automatic schema merging using mapping constraints among incomplete sources

Xiang Li, Christoph Quix, David Kensche, Sandra Geisler
2010 Proceedings of the 19th ACM international conference on Information and knowledge management - CIKM '10  
In this paper, we present a novel approach for merging multiple relational data sources related by a collection of mapping constraints in the form of P2P style tuple-generating dependencies (tgds).  ...  RELATED WORK Schema merging has a long history in database research.  ...  Let Σ be a set of tgds and egds with terminating chase, we use chase Σ (I) to denote the result of the chase using Σ over a database I. When Σ is a set of s-t tgds and target dependencies.  ... 
doi:10.1145/1871437.1871479 dblp:conf/cikm/LiQKG10 fatcat:kn2vw6ryaveb7fh3f3ozvvcrtu
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