Administering propagated metadata in large, multi-layer database systems

Enterprise databases comprise multiple local databases that exchange information. The component databases will rarely have the same native form, so one must map between the native interfaces of the data suppliers and the recipients. An SQL view is a convenient and powerful way to define this map, because it provides not just an evaluation mechanism, but also query, and (to some degree) update and trigger capabilities. However, SQL views do not map the critical metadata (e.g., security, source attribution, and quality information) between data suppliers and their recipients. The paper examines the research problems arising from the creation of a metadata propagation framework: a theory for inferring and reconciling metadata on views, rules for each property type and data derivation operator, efficient implementation, and ways to coordinate metadata administration across multiple schemas.