Querying the data web: The mashql approach

MashQL, a novel query formulation language for querying and mashing up structured data on the Web, doesn't require users to know the queried data's structure or the data itself to adhere to a schema. In this article, the authors address the fact that being a language, not merely an interface (and simultaneously schema-free), MashQL faces a particular set of challenges. In particular, the authors propose and evaluate a novel technique for optimizing queries over large data sets to allow instant user interaction.