Semantic querying of tree-structured data sources using partially specified tree patterns

Theodoratos, D; Dalamagas, T; Koufopoulos, A; Gehani, N

dc.contributor.author	Theodoratos, D	en
dc.contributor.author	Dalamagas, T	en
dc.contributor.author	Koufopoulos, A	en
dc.contributor.author	Gehani, N	en
dc.date.accessioned	2014-03-01T02:43:32Z
dc.date.available	2014-03-01T02:43:32Z
dc.date.issued	2005	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31459
dc.subject	Query evaluation	en
dc.subject	Query satisfiability	en
dc.subject	Tree-pattern queries	en
dc.subject	Tree-structured data	en
dc.subject	XML	en
dc.subject.other	Query evaluation	en
dc.subject.other	Query satisfiability	en
dc.subject.other	Tree-pattern queries	en
dc.subject.other	Tree-structured data	en
dc.subject.other	Data acquisition	en
dc.subject.other	Evaluation	en
dc.subject.other	Information analysis	en
dc.subject.other	Knowledge acquisition	en
dc.subject.other	Query languages	en
dc.subject.other	Semantics	en
dc.title	Semantic querying of tree-structured data sources using partially specified tree patterns	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1145/1099554.1099729	en
heal.identifier.secondary	http://dx.doi.org/10.1145/1099554.1099729	en
heal.publicationDate	2005	en
heal.abstract	Nowadays, huge volumes of data are organized or exported in a tree-structured form. Querying capabilities are provided through queries that are based on branching path expression. Even for a single knowledge domain structural differences raise difficulties for querying data sources in a uniform way. In this paper, we present a method for semantically querying tree-structured data sources using partially specified tree patterns. Based on dimensions which are sets of semantically related nodes in tree structures, we define dimension graphs. Dimension graphs can be automatically extracted from trees and abstract their structural information. They are semantically rich constructs that support the formulation of queries and their efficient evaluation. We design a tree-pattern query language to query multiple tree-structured data sources. A central feature of this language is that the structure can be specified fully, partially, or not at all in the queries. Therefore, it can be used to query multiple trees with structural differences. We study the derivation of structural expressions in queries by introducing a set of inference rules for structural expressions. We define two types of query unsatisfiability and we provide necessary and sufficient conditions for checking each of them. Our approach is validated through experimental evaluation. Copyright 2005 ACM.	en
heal.journalName	International Conference on Information and Knowledge Management, Proceedings	en
dc.identifier.doi	10.1145/1099554.1099729	en
dc.identifier.spage	712	en
dc.identifier.epage	719	en