1,514 research outputs found
Pattern based processing of XPath queries
As the popularity of areas including document storage and
distributed systems continues to grow, the demand for high
performance XML databases is increasingly evident. This
has led to a number of research eorts aimed at exploiting
the maturity of relational database systems in order to in-
crease XML query performance. In our approach, we use an
index structure based on a metamodel for XML databases
combined with relational database technology to facilitate
fast access to XML document elements. The query process
involves transforming XPath expressions to SQL which can
be executed over our optimised query engine. As there are
many dierent types of XPath queries, varying processing
logic may be applied to boost performance not only to indi-
vidual XPath axes, but across multiple axes simultaneously.
This paper describes a pattern based approach to XPath
query processing, which permits the execution of a group of
XPath location steps in parallel
Reasoning & Querying – State of the Art
Various query languages for Web and Semantic Web data, both for practical use and as an area of research in the scientific community, have emerged in recent years. At the same time, the broad adoption of the internet where keyword search is used in many applications, e.g. search engines, has familiarized casual users with using keyword queries to retrieve information on the internet. Unlike this easy-to-use querying, traditional query languages require knowledge of the language itself as well as of the data to be queried. Keyword-based query languages for XML and RDF bridge the gap between the two, aiming at enabling simple querying of semi-structured data, which is relevant e.g. in the context of the emerging Semantic Web. This article presents an overview of the field of keyword querying for XML and RDF
On Region Algebras, XML Databases, and Information Retrieval
This paper describes some new ideas on developing a logical algebra for databases that manage textual data and support information retrieval functionality. We describe a first prototype of such a system
Pathfinder: XQuery - The Relational Way
Relational query processors are probably the best understood (as well as the best engineered) query engines available today. Although carefully tuned to process instances of the relational model (tables of tuples), these processors can also provide a foundation for the evaluation of "alien" (non-relational) query languages: if a relational encoding of the alien data model and its associated query language is given, the RDBMS may act like a special-purpose processor for the new language
THE ROLE OF XML IN THE MODELING PROCESS OF A VIRTUAL BUSINESS
The aim of this paper is to describe the XML stack of languages used in the implementation process of a web application. This application is based on a three tier architecture named XRX. In this type of architecture there is no need for data model transformations between the tiers of the architecture like in the classical architecture. So the applications developed according XRX architecture become more flexible, efficient and simple.XML, XPath, XQuery, XSLT, XForms, XRX, UBL
06472 Abstracts Collection - XQuery Implementation Paradigms
From 19.11.2006 to 22.11.2006, the Dagstuhl Seminar 06472 ``XQuery Implementation Paradigms'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available
Web and Semantic Web Query Languages
A number of techniques have been developed to facilitate
powerful data retrieval on the Web and Semantic Web. Three categories
of Web query languages can be distinguished, according to the format
of the data they can retrieve: XML, RDF and Topic Maps. This article
introduces the spectrum of languages falling into these categories
and summarises their salient aspects. The languages are introduced using
common sample data and query types. Key aspects of the query
languages considered are stressed in a conclusion
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