Querying XML data sources that export very large sets of views

Autor:	Alin Deutsch, Bogdan Cautis, Nicola Onose, Vasilis Vassalos
Rok vydání:	2011
Předmět:	Theoretical computer science Computer science computer.internet_protocol computer.software_genre Xml data Formalism (philosophy of mathematics) Rewriting Web service computer Finite set XML Information Systems XPath
Zdroj:	ACM Transactions on Database Systems. 36:1-42
ISSN:	1557-4644 0362-5915
DOI:	10.1145/1929934.1929939
Popis:	We study the problem of querying XML data sources that accept only a limited set of queries, such as sources accessible by Web services which can implement very large (potentially infinite) families of XPath queries. To compactly specify such families of queries we adopt the Query Set Specifications, a formalism close to context-free grammars. We say that query Q is expressible by the specification P if it is equivalent to some expansion of P. Q is supported by P if it has an equivalent rewriting using some finite set of P's expansions. We study the complexity of expressibility and support and identify large classes of XPath queries for which there are efficient (PTIME) algorithms. Our study considers both the case in which the XML nodes in the results of the queries lose their original identity and the one in which the source exposes persistent node ids.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6feb31cc3f7f1aefa949de996c92d7ef https://doi.org/10.1145/1929934.1929939 Zobrazit plný text záznamu