The web-standards body W3C has published Sparql, a query language designed to gather data from multiple sources and speed the development of Web 2.0 applications — creating a standard web service for anything that asks a question.
Sparql, pronounced "sparkle", expresses data queries in high-level terms so it is easier to extend them to new data sources or port them to new applications. "Trying to use the Semantic Web without Sparql is like trying to use a relational database without SQL," said Tim Berners-Lee, W3C director and creator of the world wide web.
According to Berneers-Lee: "Sparql makes it possible to query information from databases and other diverse sources in the wild, across the web."
"Sparql is a key element for integrated information access across information silos and across business boundaries," said Jean-Luc Chatelain, chief technology officer for HP's Software Information Management business, announcing the release of SDB, a Sparql database system for HP's Jena open-source Semantic Web framework.
"HP customers can benefit from better information utilisation by employing Semantic Web technologies," he added.
Including SDB, there are 14 known implementations of Sparql, which emerged from the W3C Data Access Working Group (DAWG). Several developers are already using it, including Rome-based developer Asemantics, which is using Sparql to build a satellite image search engine for the European Space Agency, an engine to access 400 years of tidal data at the Dutch Water Authority, and a feed aggregator to access the BBC's MemoryShare archive.
Traditional query languages such as SQL are designed for accesses to a single source of data, and have not performed well when the results from several sources need to be merged. Sparql can create a single query for multiple sources and combine the results. "Because Sparql has no tie to a specific database format, it can be used to take advantage of the tidal wave of Web 2.0 data and mash it up with other Semantic Web resources," says the W3C release.
"Sparql's focus on querying the data models saves time for developers; there's no need for a host of little web services to retrieve different aspects of the state of a system," said Lee Feigenbaum, chair of the RDF Data Access Working Group. "This allows the user of the Sparql endpoint to ask any question — it is as though they could design their own interface instead of having to work with a limited set of fixed services."
Sparql works with the W3C's Resource Description Framework (RDF) for representing data and the Web Services Description Language (WSDL).