Schema matching identifies elements of two given schemas that correspond to each other. Although there are many algorithms for schema matching, little has been written about building a system that can be used in practice. We describe our initial experience building such a system, a customizable schema matcher called Protoplasm. 1 Schema Matching Most systems-integration work requires creating mappings between models, such as database schemas, message formats, interface definitions, and user-interface forms. As a design activity, schema mapping is similar to database design in that it requires digging deeply into the semantics of schemas. This is usually quite time consuming, not only in level-of-effort but also in elapsedtime, because the process of teasing out semantics is slow. It can benefit from the development of improved tools, but it is unlikely such tools will provide a silver bullet that automates all of the work. For example, it is hard to imagine how the best tool could eli...
Philip A. Bernstein, Sergey Melnik, Michalis Petro