UniQue: An Approach for Unified and Efficient Querying of Heterogeneous Web Data Sources

Governments, organizations, and people are publishing open data on the Web more than ever before. To consume the data, however, requires substantial effort from web mashup developers, as they have to familiarize themselves with a diversity of data formats and query techniques specific to each data source. While several solutions have been proposed to improve web querying, none of them covers aforementioned aspects in a developer friendly and efficient manner. Therefore, we devised a unified querying (UniQue) approach and a proxy-based implementation that provides a uniform and declarative interface for querying heterogeneous data sources across the Web. Besides hiding the differences between the underlying data formats and query techniques, UniQue heavily embraces open W3C standards to minimize the learning effort required by developers. Pursuing this further, we propose Unified Query Language (UQL) that combines the expressiveness of CSS Selectors and XPath into a single and flexible selector language. We show that the adoption of UniQue and UQL can effectively streamline web querying, leverage developers' existing knowledge, and reduce generated network traffic compared to the current state-of-the-art approach.