Tequila - a query language for the Semantic Web

In order to realize the idea of the Semantic Web, many tools and technologies need to be developed, including a query language. One of the most important technologies that creates a base for the Semantic Web is the RDF (Resource Description Framework). There are many query languages for the RDF, but almost all of them are very weak and they can not be used for a general purpose. In this paper, we introduce the Tequila query language, developed for the recently introduced Trisolda infrastructure for the Semantic Web. In particular, we describe the syntax and semantics of the Tequila language and we show usage of this language and its power on several examples. The examples show how to convert a RDF Collection into a RDF Bag or how to evaluate an aggregation function (e.g., maximum of values) without the need of a built-in support. Unlike almost all other query languages, Tequila is powerful enough to express both of the tasks.