Interactive example-driven integration and reconciliation for accessing database federations

摘要

The integration of heterogeneous databases affects two main problems: schema integration and instance integration. At both levels a mapping from local elements to global elements is specified and various conflicts caused by the heterogeneity of the sources have to be resolved. For the detection and resolution of instance-level conflicts we propose an interactive, example-driven approach. The basic idea is to combine an interactive query tool similar to query-by-example with facilities for defining and applying integration operations. This integration approach is supported by a multidatabase query language, which provides special mechanisms for conflict resolution. The foundations of these mechanisms are introduced and their usage in instance integration and reconciliation is presented. In addition, we discuss basic techniques for supporting the detection of instance-level conflicts.