A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the...
Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wa...
Regular expression matching is a key task (and often computational bottleneck) in a variety of software tools and applications. For instance, the standard grep and sed utilities, ...
It is known that the composition of schema mappings, each specified by source-to-target tgds (st-tgds), can be specified by a secondorder tgd (SO tgd). We consider the question of...
In GIS and spatial databases, cardinal directions are frequently used as selection and join criteria in query languages. However, most cardinal direction models are only able to h...
Describing relational data sources (i.e. databases) by means of ontologies constitutes the foundation of most of the semantic based approaches to data access and integration. In sp...