Ontological Queries: Rewriting and Optimization (Extended Version)
G. Gottlob, G. Orsi, and A. Pieris. (2011)cite arxiv:1112.0343Comment: Extended version of "Ontological Queries: Rewriting and Optimization" presented at ICDE 2011.
Abstract
Ontological queries are evaluated against an ontology rather than directly on
a database. The evaluation and optimization of such queries is an intriguing
new problem for database research.
In this paper we discuss two important aspects of this problem: query
rewriting and query optimization. Query rewriting consists of the compilation
of an ontological query into an equivalent query against the underlying
relational database. The focus here is on soundness and completeness. We review
previous results and present a new rewriting algorithm for rather general types
of ontological constraints.
In particular, we show how a conjunctive query against an ontology can be
compiled into a union of conjunctive queries against the underlying database.
Ontological query optimization, in this context, attempts to improve this
process so to produce possibly small and cost-effective UCQ rewritings for an
input query. We review existing optimization methods, and propose an effective
new method that works for linear Datalog+/-, a class of Datalog-based rules
that encompasses well-known description logics of the DL-Lite family.
Description
Ontological Queries: Rewriting and Optimization (Extended Version)
%0 Generic
%1 Gottlob2011
%A Gottlob, Georg
%A Orsi, Giorgio
%A Pieris, Andreas
%D 2011
%K ir ontology owl query_reformulation rdf semantic_web
%T Ontological Queries: Rewriting and Optimization (Extended Version)
%U http://arxiv.org/PS_cache/arxiv/pdf/1112/1112.0343v1.pdf
%X Ontological queries are evaluated against an ontology rather than directly on
a database. The evaluation and optimization of such queries is an intriguing
new problem for database research.
In this paper we discuss two important aspects of this problem: query
rewriting and query optimization. Query rewriting consists of the compilation
of an ontological query into an equivalent query against the underlying
relational database. The focus here is on soundness and completeness. We review
previous results and present a new rewriting algorithm for rather general types
of ontological constraints.
In particular, we show how a conjunctive query against an ontology can be
compiled into a union of conjunctive queries against the underlying database.
Ontological query optimization, in this context, attempts to improve this
process so to produce possibly small and cost-effective UCQ rewritings for an
input query. We review existing optimization methods, and propose an effective
new method that works for linear Datalog+/-, a class of Datalog-based rules
that encompasses well-known description logics of the DL-Lite family.
@misc{Gottlob2011,
abstract = { Ontological queries are evaluated against an ontology rather than directly on
a database. The evaluation and optimization of such queries is an intriguing
new problem for database research.
In this paper we discuss two important aspects of this problem: query
rewriting and query optimization. Query rewriting consists of the compilation
of an ontological query into an equivalent query against the underlying
relational database. The focus here is on soundness and completeness. We review
previous results and present a new rewriting algorithm for rather general types
of ontological constraints.
In particular, we show how a conjunctive query against an ontology can be
compiled into a union of conjunctive queries against the underlying database.
Ontological query optimization, in this context, attempts to improve this
process so to produce possibly small and cost-effective UCQ rewritings for an
input query. We review existing optimization methods, and propose an effective
new method that works for linear Datalog+/-, a class of Datalog-based rules
that encompasses well-known description logics of the DL-Lite family.
},
added-at = {2011-12-06T09:55:46.000+0100},
author = {Gottlob, Georg and Orsi, Giorgio and Pieris, Andreas},
biburl = {https://www.bibsonomy.org/bibtex/2d1b480ca83ffa36e1ef0c5687f2afa1a/maxirichter},
description = {Ontological Queries: Rewriting and Optimization (Extended Version)},
interhash = {7b48e3f4898bec1fe365702bbb195a37},
intrahash = {d1b480ca83ffa36e1ef0c5687f2afa1a},
keywords = {ir ontology owl query_reformulation rdf semantic_web},
note = {cite arxiv:1112.0343Comment: Extended version of "Ontological Queries: Rewriting and Optimization" presented at ICDE 2011},
timestamp = {2012-01-16T12:19:17.000+0100},
title = {Ontological Queries: Rewriting and Optimization (Extended Version)},
url = {http://arxiv.org/PS_cache/arxiv/pdf/1112/1112.0343v1.pdf},
year = 2011
}