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Tractable Query Answering in Indefinite Constraint Databases: Basic Results and Applications to Querying Spatiotemporal Information [chapter]

Manolis Koubarakis, Spiros Skiadopoulos
1999 Lecture Notes in Computer Science  
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]

Antoine Amarilli, Silviu Maniu, Mikaël Monet
2016 arXiv   pre-print
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]

Antoine Amarilli, Silviu Maniu, Mikaël Monet
2016 Lecture Notes in Computer Science  
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]

Giuseppe De Giacomo, Domenico Lembo, Maurizio Lenzerini, Antonella Poggi, Riccardo Rosati
2017 Studies in Big Data  
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]

Patrick Doherty, Witold Lukaszewicz, Andrzej Szalas
2000 Lecture Notes in Computer Science  
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

Wenfei Fan, Floris Geerts, Frank Neven
2013 Proceedings of the VLDB Endowment  
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

Ting Deng, Wenfei Fan
2014 ACM Transactions on Database Systems  
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

Avinash J. Agrawal, O. G. Kakde
2011 International Journal of Artificial Intelligence & Applications  
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

Ting Deng, Wenfei Fan
2013 Proceedings of the VLDB Endowment  
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

Alexander Borgida, Ronald J. Brachman, Deborah L. McGuinness, Lori Alperin Resnick
1989 SIGMOD record  
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

Alexander Borgida, Ronald J. Brachman, Deborah L. McGuinness, Lori Alperin Resnick
1989 Proceedings of the 1989 ACM SIGMOD international conference on Management of data - SIGMOD '89  
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]

Diego Calvanese, Giuseppe De Giacomo, Domenico Lembo, Maurizio Lenzerini, Riccardo Rosati, Marco Ruzzi
2009 Semantic Web Information Management  
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

L. A. Kalinichenko
2012 Programming and computer software  
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

Marek Smid, Zdenek Kouba
2012 International Semantic Web Conference  
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]

Stéphane Grumbach, Tova Milo
1995 Lecture Notes in Computer Science  
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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