The conceptual schema and external schemata of metadatabases

We consider statistical databases. They consist of three layers which refer to micro-, macro- and metadata. Metadata are viewed as data about micro- and macrodata. Metadata have non-standard characteristics, i.e. they are not fixed formatted, are highly cross-referenced and are extremely heterogenous. This is especially true for the underlying data structures and the set of operators needed for data definition, manipulation and control. Moreover, data integrity and confidentiality need special attention. We focus on the conceptual design of metadata and consider different user view´s in some detail