Subject:W3C Releases Public Working Draft for Full-Text Searching of XML Text and Documents Author:SSDN Admin Date:13 Jul 2004 06:48 PM
The W3C has published an initial Public Working Draft for XQuery 1.0 and XPath 2.0 Full-Text. Created as a joint specification by the W3C XML Query Working Group and the XSL Working Group as part of the XML Activity, the new draft specification defines a language that extends XQuery 1.0 and XPath 2.0 with full-text search capabilities.
As defined by the draft, "full-text queries are performed on text which has been tokenized, i.e., broken into a sequence of words, units of punctuation, and spaces." New full-text search facility is implemented by extending the XQuery and XPath languages to support a new "FTContainsExpr" expression and a new "ft:score" function.
Expressions of the type FTSelection are composed of:(1) words or combinations of words that are the search strings to be found as matches; (2) Match options such as case sensitivity or an indication to use stop words; (3) Boolean operators that allow composition of an FTSelection from simpler FTSelections; (4) Positional constraints such as indication of match distance or window.
The new Full-Text Working Draft endeavors to meet search requirements specified in an updated companion draft XQuery 1.0 and XPath 2.0 Full-Text Use Cases. This document provides use cases designed to "illustrate important applications of full-text querying within an XML query language. Each use case exercises a specific functionality relevant to full-text querying. An XML Schema and sample input data are provided; each use case specifies a query applied to the input data, a solution in XQuery, a solution in XPath (when possible), and the expected results."