Evaluation of partial path queries on XML data

Souldatos, S; Wu, X; Theodoratos, D; Dalamagas, T; Sellis, T

dc.contributor.author	Souldatos, S	en
dc.contributor.author	Wu, X	en
dc.contributor.author	Theodoratos, D	en
dc.contributor.author	Dalamagas, T	en
dc.contributor.author	Sellis, T	en
dc.date.accessioned	2014-03-01T02:44:36Z
dc.date.available	2014-03-01T02:44:36Z
dc.date.issued	2007	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31903
dc.subject	Partial path-pattern query	en
dc.subject	Query evaluation	en
dc.subject	Tree-structured data	en
dc.subject.other	Directed acyclic graphs	en
dc.subject.other	Experimental evaluations	en
dc.subject.other	Inference rules	en
dc.subject.other	Intermediate results	en
dc.subject.other	Key operations	en
dc.subject.other	Partial path-pattern query	en
dc.subject.other	Path queries	en
dc.subject.other	Pattern query languages	en
dc.subject.other	Query evaluation	en
dc.subject.other	Query graphs	en
dc.subject.other	Query patterns	en
dc.subject.other	Spanning trees	en
dc.subject.other	Structural patterns	en
dc.subject.other	Structural relationships	en
dc.subject.other	Sufficient conditions	en
dc.subject.other	Topological orders	en
dc.subject.other	Tree-structured data	en
dc.subject.other	XML datum	en
dc.subject.other	Xml query languages	en
dc.subject.other	Xml query processing	en
dc.subject.other	XML trees	en
dc.subject.other	Algorithms	en
dc.subject.other	Knowledge management	en
dc.subject.other	Linguistics	en
dc.subject.other	Markup languages	en
dc.subject.other	Query processing	en
dc.subject.other	Trees (mathematics)	en
dc.subject.other	XML	en
dc.subject.other	Query languages	en
dc.title	Evaluation of partial path queries on XML data	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1145/1321440.1321446	en
heal.identifier.secondary	http://dx.doi.org/10.1145/1321440.1321446	en
heal.publicationDate	2007	en
heal.abstract	XML query languages typically allow the specification of structural patterns of elements. Finding the occurrences of such patterns in an XML tree is the key operation in XML query processing. Many algorithms have been presented for this operation. These algorithms focus mainly on the evaluation of path-pattern or tree-pattern queries. In this paper, we define a partial path-pattern query language, and we address the problem of its efficient evaluation on XML data. In order to process partial path-pattern queries, we introduce a set of sound and complete inference rules to characterize structural relationship derivation. We provide necessary and sufficient conditions for detecting query unsatisfi- ability and node redundancy. We show how partial path-pattern queries can be equivalently put in a canonical directed acyclic graph form. We developed two stack-based algorithms for the evaluation of partial path-pattern queries, Partial MJ and Partial Path Stack. Partial MJ computes answers to the query by merge-joining the results of the root-to-leaf paths of a spanning tree of the query. Partial- PathStack exploits a topological order of the nodes of the query graph to match the query pattern as a whole to the XML tree. The experimental evaluation of our algorithms shows that Partial Path Stack is independent of intermediate results and largely outperforms Partial MJ. Copyright 2007 ACM.	en
heal.journalName	International Conference on Information and Knowledge Management, Proceedings	en
dc.identifier.doi	10.1145/1321440.1321446	en
dc.identifier.spage	21	en
dc.identifier.epage	30	en