Efficient evaluation of XQuery and XPath full text extension
US8312030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 2009 |
| Grant date | Nov 13, 2012 |
| Priority date | — |
| Expiry date | Dec 25, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/835
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are provided for efficiently evaluating XML queries that conform to an extension of an XML language (e.g., XQuery or XPath). The extension allows XML queries to have full-text search capabilities. Such an XML query is compiled to generate a tree of nodes that correspond to one or more conditions in the full-text portion of the query. In one technique, the amount of memory for the execution state of the tree is determined at compile time and allocated only once throughout execution of the query. In another technique, to ensure at most a single scan of a document, all the words or phrases in the full-text portion of an XML query are located before any of the other conditions in the full-text portion are evaluated. In another technique, the elements of the full-text portion of an XML query are analyzed to determine, based at least in part on cost, which evaluation strategy, of a plurality of evaluation strategies, should be employed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.