A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
Filters
Tractability in probabilistic databases
2011
Proceedings of the 14th International Conference on Database Theory - ICDT '11
Preserved Fulltext
Probabilistic database, query evaluation Probabilistic databases are motivated by a large and diverse set of applications that need to query and process uncertain data. ...
All these applications have large collections of data, where some, or most individual data items are uncertain. ...
Acknowledgment The author was partially supported by NSF IIS-0713576. ...
doi:10.1145/1938551.1938553
dblp:conf/icdt/Suciu11
fatcat:atm4n47iwzh73k7slig5v75taa
Repair checking in inconsistent databases
2009
Proceedings of the 12th International Conference on Database Theory - ICDT '09
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
Theorem If Σ is the union of a weakly acyclic set of LAV tgds and a set of egds, then the subset-repair checking problem w.r.t. Σ is in PTIME; in fact, it is in LOGSPACE. Proof Idea. ...
Key property of LAV tgds: only single facts fire a tgd (and no combinations of facts). Hence, LAV tgds are preserved under unions of models. ...
The consistent answers of q on r w.r.t. ...
doi:10.1145/1514894.1514899
dblp:conf/icdt/AfratiK09
fatcat:lvijjkbivnallpzuugigf2w634
Tackling Polytype Queries in Inconsistent Databases: Theory and Algorithm
2012
Journal of Software
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
This paper presents several algorithms to tackle a large and practical class of queries, which can obtain the rewritten queries for computing consistent answers. ...
For a rewritable initial query, a consistent identification statement is constructed based on the join graph by recursive computation; and the statement combines with the initial query to construct a new ...
The consistent answers for q1 on I are the tuples (Tom) and (Mary). Let q 2 (name, age) = R (name, age). The only consistent answer for q 2 on I is (Mary, 30). ...
doi:10.4304/jsw.7.8.1861-1866
fatcat:oleyvdabkvb7xfz2e2avof2are
Tractable vs. Intractable Cases of Query Answering under Matching Dependencies
[chapter]
2014
Lecture Notes in Computer Science
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
Previous work identified classes of queries and sets of MDs for which resolved query answering is tractable, with special emphasis on cyclic sets of MDs. ...
In those tractable cases, we find conjunctive queries with certain restrictions on joins, and sets of MDs that cyclically depend on each other. These are the (cyclic) HSC sets identified in [14] . ...
We identify a class of conjunctive queries that are relevant for the investigation of tractability vs. intractability of RQA. ...
doi:10.1007/978-3-319-11508-5_5
fatcat:3qvbckykmrcy7iobppyipesipq
On the Complexity of Consistent Query Answering in the Presence of Simple Ontologies
2021
PROCEEDINGS OF THE THIRTIETH AAAI CONFERENCE ON ARTIFICIAL INTELLIGENCE AND THE TWENTY-EIGHTH INNOVATIVE APPLICATIONS OF ARTIFICIAL INTELLIGENCE CONFERENCE
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2022; you can also visit the original URL.
The file type is application/pdf.
In order to better understand the source of this intractability, we investigate the complexity of consistent query answering for simple ontologies consisting only of class subsumption and class disjointness ...
Recent work on consistent query answering in the presence of ontologies has shown this problem to be intractable in data complexity even for ontologies expressed in lightweight description logics. ...
a given set of integrity constraints (typically, functional dependencies) and a given CQ, whether the associated consistent query answering problem is first-order expressible, tractable, or intractable ...
doi:10.1609/aaai.v26i1.8218
fatcat:5eavfcgoorffha4znlxpbpbxry
Small is Again Beautiful in Description Logics
2010
Künstliche Intelligenz
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2011; you can also visit the original URL.
The file type is application/pdf.
OWL DL, the standard ontology language for the Semantic Web, is based on such an expressive DL for which reasoning is highly intractable. ...
This and other reasons have led to the development of two new families of light-weight DLs, EL and DL-Lite, which recently have been proposed as profiles of OWL 2, the new version of the OWL standard. ...
Given a union of conjunctive queries or a conjunctive query q and a knowledge base K, the set of answers to q over K (denoted ans(q, K)) consists of all tuples a of individual names appearing in the knowledge ...
doi:10.1007/s13218-010-0004-8
fatcat:mqdsof4hcnfibgouuai35ibda4
On the Complexity of Query Answering under Matching Dependencies for Entity Resolution
[article]
2013
arXiv
pre-print
Preserved Fulltext
The Internet Archive has a preservation copy of this work in our general collections.
The file type is application/pdf.
Other Versions
In previous work we identified some tractable cases (i.e. for certain classes of queries and MDs) of resolved query answering. ...
The resolved answers to queries are those that are invariant under the resulting class of resolved instances. ...
The idea is to rewrite a query, say conjunctive, into a new query such that the new query on the inconsistent database returns as usual answers the consistent answers to the original query. ...
arXiv:1304.7854v2
fatcat:je672nxxv5dizd27ggcmdimzqe
First-order query rewriting for inconsistent databases
2007
Journal of computer and system sciences (Print)
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2006; you can also visit the original URL.
The file type is application/pdf.
In contrast, in this paper we give an algorithm that computes the consistent answers for a large and practical class of conjunctive queries. ...
In particular, we concentrate on sets of constraints that consist of key dependencies. Most of the existing work has focused on identifying intractable cases of this problem. ...
We would like to thank Leonid Libkin, Marcelo Arenas, Pablo Barcelo, and Ken Pu for their comments and feedback. ...
doi:10.1016/j.jcss.2006.10.013
fatcat:ecyabmao4ncctot7e4qodwy52a
First-Order Query Rewriting for Inconsistent Databases
[chapter]
2004
Lecture Notes in Computer Science
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2006; you can also visit the original URL.
The file type is application/pdf.
In contrast, in this paper we give an algorithm that computes the consistent answers for a large and practical class of conjunctive queries. ...
In particular, we concentrate on sets of constraints that consist of key dependencies. Most of the existing work has focused on identifying intractable cases of this problem. ...
We would like to thank Leonid Libkin, Marcelo Arenas, Pablo Barcelo, and Ken Pu for their comments and feedback. ...
doi:10.1007/978-3-540-30570-5_23
fatcat:snnu2sghyzavxbji2pgovypjye
Enumeration in Data Management (Dagstuhl Seminar 19211)
2019
Dagstuhl Reports
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2022; you can also visit the original URL.
The file type is application/pdf.
Towards the objectives, the seminar included tutorials on the topic, invited talks, presentations of open problems, working groups on the open problems, discussions on platforms to compile the community ...
knowledge, and the construction of various skeletons of such compilations. ...
We show that some non-redundant unions containing intractable CQs are tractable. Interestingly, some unions consisting of only intractable CQs are tractable too. ...
doi:10.4230/dagrep.9.5.89
dblp:journals/dagstuhl-reports/BorosKPS19
fatcat:gfir76niqfhmno2hpj563cwwqe
Query languages for data exchange
2009
Proceedings of the 12th International Conference on Database Theory - ICDT '09
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
In particular, we show that the certain answers to a DATALOG C( =) program can be computed in polynomial time (in terms of data complexity), and that every union of conjunctive queries with at most one ...
This syntactic restriction is given by two conditions that are optimal, in the sense that computing certain answers becomes intractable if one removes any of them. ...
The authors were supported by: Arenas and Reutter -FONDECYT grant 1070732; Barceló -FONDECYT grant 11080011; Arenas and Barceló -grant P04-067-F from the Millennium Nucleus Centre for Web Research. ...
doi:10.1145/1514894.1514904
dblp:conf/icdt/ArenasBR09
fatcat:lvnmfo35xngwzn5a4xrcxr6sve
Query Languages for Data Exchange: Beyond Unions of Conjunctive Queries
2010
Theory of Computing Systems
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is application/pdf.
In particular, we show that the certain answers to a DATALOG C( =) program can be computed in polynomial time (in terms of data complexity), and that every union of conjunctive queries with at most one ...
This syntactic restriction is given by two conditions that are optimal, in the sense that computing certain answers becomes intractable if one removes any of them. ...
The authors were supported by: Arenas and Reutter -FONDECYT grant 1070732; Barceló -FONDECYT grant 11080011; Arenas and Barceló -grant P04-067-F from the Millennium Nucleus Centre for Web Research. ...
doi:10.1007/s00224-010-9259-6
fatcat:vhf7p6m2h5gcbbgw5drytzarzi
XML data exchange
2005
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '05
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2010; you can also visit the original URL.
The file type is application/pdf.
We then move to query answering, and prove a dichotomy theorem that classifies data exchange settings into those over which query answering is tractable, and those over which it is coNP-complete, depending ...
In this paper, we start looking into the basic properties of XML data exchange, that is, restructuring of XML documents that conform to a source DTD under a target DTD, and answering queries written over ...
comments on the draft. ...
doi:10.1145/1065167.1065171
dblp:conf/pods/ArenasL05
fatcat:7sbvhte7mnapxnp4w7uwdopz5e
On the efficiency of checking perfect privacy
2006
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '06
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2007; you can also visit the original URL.
The file type is application/pdf.
One very attractive notion of privacy is perfect privacy -a secret is expressed through a query QS, and a query QV is answered only if it discloses no information about the secret query QS. ...
In this paper, we show that for large interesting subclasses of conjunctive queries enforcing perfect privacy is tractable. ...
Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the sponsors. ...
doi:10.1145/1142351.1142375
dblp:conf/pods/MachanavajjhalaG06
fatcat:fbr6hv5cufcnlc222vgoxk4wjq
Tractable Cases of Clean Query Answering under Entity Resolution via Matching Dependencies
[chapter]
2012
Lecture Notes in Computer Science
Preserved Fulltext
A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2012; you can also visit the original URL.
The file type is application/pdf.
The clean answers to queries (which we call the resolved answers) are invariant under the resulting class of instances. ...
This is an important result, because it leads to tractable cases of resolved query answering. Further tractable cases are derived by making connections with tractable cases of CQA. ...
The latter paper introduced the framework used in this paper, and proved that the resolved answer problem is intractable in some cases. ...
doi:10.1007/978-3-642-33362-0_14
fatcat:b2f35idgp5c4lbesgmzbvrzkmm
« Previous
Showing results 1 — 15 out of 2,062 results