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...
Flexible and dynamic environments are characterized by high independence from connection participants, low control over available services and high tolerance to communication fail...
We study the problem of answering queries through a target schema, given a set of mappings between one or more source schemas and this target schema, and given that the data is at...
Accessing and integrating data from heterogeneous sources has become a significant challenge. So-called adapters provide the functionality for translating SQL queries into querie...
Execution plans produced by traditional query optimizers for data integration queries may yield poor performance for several reasons. The cost estimates may be inaccurate, the mem...