Section: Scientific Foundations

Efficient XML and RDF data management

The development of Web technologies has led to a strong increase in the number and complexity of the applications which represent their data in Web formats, among which XML (for structured documents) and RDF (for Semantic Web data) are the most prominent. Oak has carried on research on algorithms and systems for efficiently processing expressive queries on such Web data formats. We have considered the efficient management of XML and RDF data, both for query evaluation and for efficiently applying updates, possibly in concurrence with queries. We have also started investigating multidimensional data analysis within RDF data warehouses.

For applications that integrate such Web data from various sources, we developed efficient and effective techniques to automatically recognize multiple representations of the same real-world object. That is, we devised main-memory resident algorithms that apply on hierarchical data [8] as well as algorithms that manipulate graph data leveraging off-the-shelf database management systems and parallelization to address both efficiency and scalability beyond main-memory [7] .