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Tractable Query Answering in Indefinite Constraint Databases: Basic Results and Applications to Querying Spatiotemporal Information
[chapter]
1999
Lecture Notes in Computer Science
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Under this assumption, we show that there are several general classes of databases and queries for which query evaluation can be done with PTIME data complexity. ...
Tractable query answering problems for indefinite temporal and spatial constraint databases are identified in this way. ...
This research has been partially supported by European project CHOROCHRONOS (funded under Framework IV) and by a grant from the Greek Secretariat for Research and Technology. ...
doi:10.1007/3-540-48344-6_12
fatcat:z2wkay2wwvfdfjg74ibpsvvuwi
Challenges for Efficient Query Evaluation on Structured Probabilistic Data
[article]
2016
arXiv
pre-print
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This paper presents a vision for a database management system for probabilistic data built following this structural approach. ...
However, a new approach for this problem has recently been proposed, based on structural decompositions of input databases, following, e.g., tree decompositions. ...
All these methods would be generally intractable in the query, which is unsurprising: indeed, PQE is often intractable even for languages with tractable combined complexity, and efficient compilation to ...
arXiv:1607.05538v1
fatcat:mfmr5c6lvrg3vgvk6qdngsfw5e
Challenges for Efficient Query Evaluation on Structured Probabilistic Data
[chapter]
2016
Lecture Notes in Computer Science
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This paper presents a vision for a database management system for probabilistic data built following this structural approach. ...
However, a new approach for this problem has recently been proposed, based on structural decompositions of input databases, following, e.g., tree decompositions. ...
generalize to arbitrary queries: it may even be the case that some queries cannot be rewritten to the summary facts while remaining in the same language. ...
doi:10.1007/978-3-319-45856-4_22
fatcat:5yramxr62feb7ju5ubl7olomrm
Using Ontologies for Semantic Data Integration
[chapter]
2017
Studies in Big Data
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Over the past two decades, the idea of using semantics for data integration has become increasingly crucial, and has received much attention in the AI, database, web, and data mining communities. ...
Here, we focus on a specific paradigm for semantic data integration, called Ontology-Based Data Access (OBDA). ...
As for the query language, we note that going beyond unions of CQs is problematic from the point of view of tractability, or even decidability. ...
doi:10.1007/978-3-319-61893-7_11
fatcat:l6ldfj7pifadtioszweo5aenwy
Efficient Reasoning Using the Local Closed-World Assumption
[chapter]
2000
Lecture Notes in Computer Science
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The approach is based on the use of circumscription and quanti er elimination techniques and inference is viewed as querying a deductive database. ...
Both the preprocessing of the database using circumscription and quanti er elimination, and the inference method itself, have polynomial time and space complexity. In ...
Conclusions We have extended and subsumed the LCW querying techniques described in 9 , 3, 4 , and 10 and presented a tractable algorithm. ...
doi:10.1007/3-540-45331-8_5
fatcat:dgtabguqobcftlaftsn6woprji
Making queries tractable on big data with preprocessing
2013
Proceedings of the VLDB Endowment
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This paper aims to provide a formal foundation for this approach in terms of computational complexity. (1) We propose a set of Π-tractable queries, denoted by ΠT 0 Q , to characterize classes of queries ...
set ΠT Q of query classes that can be effectively converted to Π-tractable queries by re-factorizing its data and queries for preprocessing. ...
When we study the complexity class of all Π-tractable queries, we consider w.l.o.g. Boolean query languages Q [1], as usual. ...
doi:10.14778/2536360.2536368
fatcat:rokfd5eeangjbagivtbwgbz2oq
On the Complexity of Query Result Diversification
2014
ACM Transactions on Database Systems
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We study these problems for a variety of query languages and for three objective functions. ...
This paper studies the complexity of result diversification for relational queries. ...
, i.e., the complexity of evaluating a fixed query for variable database inputs (see [1] for details). ...
doi:10.1145/2602136
fatcat:a5t4c5nsujhtvfs3p2k35vsxhu
Object-Relational Database Based Category Data Model for Natural Language Interface to Database
2011
International Journal of Artificial Intelligence & Applications
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In this paper an effective category model is presented to organize information according to their contents based on object-relational database. ...
Domain specific question answering technique allows users to use natural language to express their queries so that users need not have the knowledge about the structures of the information source. ...
The query language used in object-relational database is the ORSQL that is a dialect of SQL-3. ...
doi:10.5121/ijaia.2011.2103
fatcat:xot6rvbqjjardmsbsx2t3uyx7m
On the complexity of query result diversification
2013
Proceedings of the VLDB Endowment
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We study these problems for a variety of query languages and for three objective functions. ...
This paper studies the complexity of result diversification for relational queries. ...
, i.e., the complexity of evaluating a fixed query for variable database inputs (see [1] for details). ...
doi:10.14778/2536354.2536358
fatcat:mrsuoyqjmvfq3dtmemkv333ssm
CLASSIC: a structural data model for objects
1989
SIGMOD record
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The kind of language of descriptions and queries presented here provides a new arena for the search for languages that are more expressive than conventional DBMS languages, but for which query processing ...
is still tractable. ...
We take the database component of a complex application to be a cache for persistent information of limited complexity. 2 The CLASSIC approach: structured concepts A classic database is mostly a repository ...
doi:10.1145/66926.66932
fatcat:j4epfkch3ndqxgjaruy5f5vg5y
CLASSIC: a structural data model for objects
1989
Proceedings of the 1989 ACM SIGMOD international conference on Management of data - SIGMOD '89
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The kind of language of descriptions and queries presented here provides a new arena for the search for languages that are more expressive than conventional DBMS languages, but for which query processing ...
is still tractable. ...
We take the database component of a complex application to be a cache for persistent information of limited complexity. 2 The CLASSIC approach: structured concepts A classic database is mostly a repository ...
doi:10.1145/67544.66932
dblp:conf/sigmod/BorgidaBMR89
fatcat:psto7qbwhjbmjmh3c7wv62avay
Using OWL in Data Integration
[chapter]
2009
Semantic Web Information Management
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complexity of query answering under different instantiations of the framework in terms of query language and form and interpretation of the mapping. ...
of the language and computational complexity of reasoning. ...
Ideally, the complexity we aim at is the one required for evaluation of SQL queries over relational databases. ...
doi:10.1007/978-3-642-04329-1_17
fatcat:tll42v56mzfbfmditjlz56j7uq
Effective support of databases with ontological dependencies: Relational languages instead of description logics
2012
Programming and computer software
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The paper provides a brief survey of the languages for efficient support of access to the databases satisfying the ontological dependencies. ...
The main part of the paper is devoted to the survey of the development of relational database languages providing broader and more efficient support of queries over databases with the ontological dependencies ...
ACKNOWLEDGMENTS This work was supported in part by the Russian Foundation for Basic Research (project nos. 10 07 00342 a and 11 07 00402 a) and by the Presidium of the Russian Academy of Sciences (the ...
doi:10.1134/s0361768812060059
fatcat:aezozh4o6rctjft47p3uny4lnm
OnGIS: Ontology Driven Geospatial Search and Integration
2012
International Semantic Web Conference
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Helping non-expert users to query over complex spatial data requires abstracting from GIS services and operations. This paper introduces an abstraction layer based on OWL ontologies. ...
The language OWL 2 QL has been chosen as it performs open-world semantic web reasoning suitable for data integration, while having good computational properties. ...
The main advantage of OWL 2 QL over OWL 2 DL is its tractability, which allows for storing instances in a relational database and posing ontological queries 2 by means of query reformulation to SQL 3 . ...
dblp:conf/semweb/SmidK12
fatcat:mj7fdwvbtraubkdemllr7avwmm
An algebra for pomsets
[chapter]
1995
Lecture Notes in Computer Science
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We study languages for manipulating partially ordered structures with duplicates (e.g. trees, lists). As a general framework, we consider the pomset (partially ordered multiset) datatype. ...
We introduce an algebra for pomsets, which generalizes traditional algebras for (nested) sets, bags and lists. ...
Acknowledgments: The authors wish to thank Vassos Hadzilacos for technical remarks. ...
doi:10.1007/3-540-58907-4_16
fatcat:dydnv63vmzh35oofg4lhu6z5pi
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