A Trichotomy for Regular Simple Path Queries on Graphs

Bagan, Guillaume; Bonifati, Angela; Groz, Benoit

Type de document :

Communication dans un congrès avec actes

Titre :

A Trichotomy for Regular Simple Path Queries on Graphs

Auteur(s) :

Bagan, Guillaume [Auteur]
Linking Dynamic Data [LINKS]
Laboratoire d'Informatique Fondamentale de Lille [LIFL]
Bonifati, Angela [Auteur]
Linking Dynamic Data [LINKS]
Laboratoire d'Informatique Fondamentale de Lille [LIFL]
Groz, Benoit [Auteur]
Department of Computer Science [Haifa]

Titre de la manifestation scientifique :

ACM PODS

Ville :

New York

Pays :

Etats-Unis d'Amérique

Date de début de la manifestation scientifique :

2013-06-22

Titre de l’ouvrage :

Principles of Database Systems

Date de publication :

2013-06-22

Discipline(s) HAL :

Informatique [cs]/Base de données [cs.DB]
Informatique [cs]/Mathématique discrète [cs.DM]

Résumé en anglais : [en]

Regular path queries (RPQs) select nodes connected by some path in a graph. The edge labels of such a path have to form a word that matches a given regular expression. We investigate the evaluation of RPQs with an additional ...
Lire la suite >Regular path queries (RPQs) select nodes connected by some path in a graph. The edge labels of such a path have to form a word that matches a given regular expression. We investigate the evaluation of RPQs with an additional constraint that prevents multiple traversals of the same nodes. Those regular simple path queries (RSPQs) find several applications in practice, yet they quickly become intractable, even for basic languages such as (aa)* or a*ba*. In this paper, we establish a comprehensive classification of regular languages with respect to the complexity of the corresponding regular simple path query problem. More precisely, we identify the fragment that is maximal in the following sense: regular simple path queries can be evaluated in polynomial time for every regular language L that belongs to this fragment and evaluation is NP-complete for languages outside this fragment. We thus fully characterize the frontier between tractability and intractability for RSPQs, and we refine our results to show the following trichotomy: Evaluations of RSPQs is either AC0, NL-complete or NP-complete in data complexity, depending on the regular language L. The fragment identified also admits a simple characterization in terms of regular expressions. Finally, we also discuss the complexity of the following decision problem: decide, given a language L, whether finding a regular simple path for L is tractable. We consider several alternative representations of L: DFAs, NFAs or regular expressions, and prove that this problem is NL-complete for the first representation and PSPACE-complete for the other two. As a conclusion we extend our results from edge-labeled graphs to vertex-labeled graphs and vertex-edge labeled graphs.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Commentaire :

15 pages, PODS13 conference

Collections :