Union rewritings for XPath fragments

Afrati, F; Damigos, M; Gergatsoulis, M

dc.contributor.author	Afrati, F	en
dc.contributor.author	Damigos, M	en
dc.contributor.author	Gergatsoulis, M	en
dc.date.accessioned	2014-03-01T02:47:30Z
dc.date.available	2014-03-01T02:47:30Z
dc.date.issued	2011	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/33186
dc.subject	Multiple Views	en
dc.subject	Necessary and Sufficient Condition	en
dc.subject.other	Multiple views	en
dc.subject.other	Query containment	en
dc.subject.other	Sufficient conditions	en
dc.subject.other	XPath queries	en
dc.subject.other	Computer applications	en
dc.title	Union rewritings for XPath fragments	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1145/2076623.2076630	en
heal.identifier.secondary	http://dx.doi.org/10.1145/2076623.2076630	en
heal.publicationDate	2011	en
heal.abstract	In this paper, we study the problem of finding an equivalent rewriting of an XPath query using multiple views, and we show that the union operator may be required in order to find such a rewriting. In particular, focusing on the fragment of XPath containing both descendant edges and wildcard labels, we propose an algorithm that outputs a union of single-view rewritings (if there exists any) which equivalently rewrites a given query. For the same fragment of XPath, we give necessary and sufficient conditions for query containment and equivalence of unions of queries. © 2011 ACM.	en
heal.journalName	ACM International Conference Proceeding Series	en
dc.identifier.doi	10.1145/2076623.2076630	en
dc.identifier.spage	43	en
dc.identifier.epage	51	en