D3.3 Techniques for handling inconsistency and incompleteness in the IIM

Short Description:

In this document, we deal with the integration of incomplete and inconsistent data in the Information Integration Model (IIM). More specifically, we study query answering in the IIM and investigate the interaction among different kinds of constraints that can be specified on the global schema of a data integration system. We first identify cases in which query answering is undecidable. Then, we study the computational complexity of the problem for the decidable cases, and provide complexity lower bounds for different combinations of dependencies.