Reasoning on web data: Algorithms and performance

Techniques for efficiently managing Semantic Web data have attracted significant interest from the data management and knowledge representation communities. A great deal of effort has been invested, especially in the database community, into algorithms and tools for efficient RDF query evaluation. However, the main interest of RDF lies in its blending of heterogeneous data and semantics. Simple RDF graphs can be seen as collections of facts, which may be further enriched with ontological schemas, or semantic constraints, based on which reasoning can be applied to infer new information. Taking into account this implicit information is crucial for answering queries.