Computing Possible and Certain Answers ...
Type de document :
Article dans une revue scientifique
URL permanente :
Titre :
Computing Possible and Certain Answers over Order-Incomplete Data
Auteur(s) :
Amarilli, Antoine [Auteur]
Data, Intelligence and Graphs [DIG]
Ba, Mouhamadou Lamine [Auteur]
Deutch, Daniel [Auteur]
Tel Aviv University [TAU]
Senellart, Pierre [Auteur]
Value from Data [VALDA]
Data, Intelligence and Graphs [DIG]
Data, Intelligence and Graphs [DIG]
Ba, Mouhamadou Lamine [Auteur]
Deutch, Daniel [Auteur]
Tel Aviv University [TAU]
Senellart, Pierre [Auteur]
Value from Data [VALDA]
Data, Intelligence and Graphs [DIG]
Titre de la revue :
Theoretical Computer Science
Pagination :
42-76
Éditeur :
Elsevier
Date de publication :
2019
ISSN :
1879-2294
Mot(s)-clé(s) en anglais :
Uncertain data
Partial order
Certain answer
Possible answer
Partial order
Certain answer
Possible answer
Discipline(s) HAL :
Informatique [cs]/Base de données [cs.DB]
Informatique [cs]/Web
Informatique [cs]/Web
Résumé en anglais : [en]
This paper studies the complexity of query evaluation for databases whose relations are partially ordered; the problem commonly arises when combining or transforming ordered data from multiple sources. We focus on queries ...
Lire la suite >This paper studies the complexity of query evaluation for databases whose relations are partially ordered; the problem commonly arises when combining or transforming ordered data from multiple sources. We focus on queries in a useful fragment of SQL, namely positive relational algebra with aggregates, whose bag semantics we extend to the partially ordered setting. Our semantics leads to the study of two main computational problems: the possibility and certainty of query answers. We show that these problems are respectively NP-complete and coNP-complete, but identify tractable cases depending on the query operators or input partial orders. We further introduce a duplicate elimination operator and study its effect on the complexity results.Lire moins >
Lire la suite >This paper studies the complexity of query evaluation for databases whose relations are partially ordered; the problem commonly arises when combining or transforming ordered data from multiple sources. We focus on queries in a useful fragment of SQL, namely positive relational algebra with aggregates, whose bag semantics we extend to the partially ordered setting. Our semantics leads to the study of two main computational problems: the possibility and certainty of query answers. We show that these problems are respectively NP-complete and coNP-complete, but identify tractable cases depending on the query operators or input partial orders. We further introduce a duplicate elimination operator and study its effect on the complexity results.Lire moins >
Langue :
Anglais
Comité de lecture :
Oui
Audience :
Internationale
Vulgarisation :
Non
Collections :
Source :
Date de dépôt :
2022-06-15T02:26:45Z
Fichiers
- http://arxiv.org/pdf/1801.06396
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