UMAP: A Universal Layer for Schema Mapping Languages

Schema mappings are fundamental notions in data exchange and integration for relating source and target schemas. Visual mapping languages provide graphical means to visually describe such transformations. There is a plethora of tools and languages available however all use different notions and visualizations and are hardly extensible. In this paper we propose a new universal layer for schema mapping languages which provides a unified abstraction and middleware for highlevel visual mapping languages. We use only standardized Uml and Ocl artifacts which allow for easy code generation in a number of target languages (e.g. Xml, Java, or C++ code) and for a modular extension mechanism to support complex schema mappings (like second-order dependencies). We illustrate our layer by translating key elements of Clip, a recent visual mapping language more expressive than the well-known Ibm Clio mapping tool.