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dc.contributor.authorWang, Junhuen_US
dc.contributor.authorYu, Jeffreyen_US
dc.contributor.authorLiu, Chengfeien_US
dc.contributor.editorG Goos, J Hartmanisen_US
dc.date.accessioned2017-05-03T14:22:22Z
dc.date.available2017-05-03T14:22:22Z
dc.date.issued2007en_US
dc.date.modified2008-04-28T03:07:14Z
dc.identifier.issn03029743en_US
dc.identifier.doi10.1007/978-3-540-76993-4_1en_AU
dc.identifier.urihttp://hdl.handle.net/10072/17991
dc.description.abstractWe study and present our findings on two closely related problems on xpath rewriting using views when both the view and the query are tree patterns involving /,// and []. First, given view V and query Q, is it possible for Q to have an equivalent rewriting using V which is the union of two or more tree patterns, but not an equivalent rewriting which is a single pattern? This problem is of both theoretical and practical importance because, if the answer is no, then, to answer a query completely using the views, we should use more efficient methods, such as the PTIME algorithm of [13], to find the equivalent rewriting, rather than try to find the union of all contained rewritings and test its equivalence to Q. Second, given a set V of views, we want to know under what conditions a subset V of the views are redundant in the sense that for any query Q, the contained rewritings of Q using the views in V are contained in those using the views in V -V . Solving this problem can help us to, for example, choose the minimum number of views to be cached, or better design the virtual schema in a mediated data integration system, or avoid repeated calculation in query optimization. We provide necessary and sufficient conditions for the second problem, based on answers to the first problem. When the views produce comparable answers, we extend our findings to include the case where the intersection of views, in addition to the individual views, are used in the rewriting.en_US
dc.description.peerreviewedYesen_US
dc.description.publicationstatusYesen_AU
dc.format.extent218123 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglishen_US
dc.language.isoen_AU
dc.publisherSpringeren_US
dc.publisher.placeGermanyen_US
dc.relation.ispartofstudentpublicationNen_AU
dc.relation.ispartofpagefrom1en_US
dc.relation.ispartofpageto12en_US
dc.relation.ispartofjournalLecture Notes in Computer scienceen_US
dc.relation.ispartofvolume4831en_US
dc.rights.retentionYen_AU
dc.subject.fieldofresearchcode280108en_US
dc.titleOn tree pattern query rewriting using viewsen_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Peer Reviewed (HERDC)en_US
dc.type.codeC - Journal Articlesen_US
gro.facultyGriffith Sciences, School of Information and Communication Technologyen_US
gro.rights.copyrightCopyright 2007 Springer-Verlag. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. The original publication is available at www.springerlink.comen_AU
gro.date.issued2007
gro.hasfulltextFull Text


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