A general report is presented on an approach problem of privacy-oriented information systems. The report is based on extensive research experiences in specifying the structure of such a system, including the underlying data model and the privacy policy, as well as on the insight gained from a prototype implementation of selected parts of the specification. The system is called DORIS (datenschutz-orientiertes informations system). While the model is basically object-oriented, it is possible conveniently to describe an application by non-first-normal-form tuples and relations, and the data-manipulation language is high-level and relational. An expression is evaluated in three stages: navigation in the set of surrogates of persons, asking for knowledge, and finally normalization, prime value processing and output preparation. A prototype implementation of selected parts of the model is based on a kernel concept.>

In a universal relation view queries are expressed without mentioning relation names and they are evaluated by using socalled window functions.We discuss several design rules for database schemes suited for universal relation views and formalize one of them, the One Flavor Assumption.Intuitively the One Flavor Assumption says that the real world significance of any tuple of a window does not depend on the details of its construction.For its formalization we define the essence of join paths which are used in the universal relation system DURST.We prove a deep connection between database schemes satisfying the One Flavor Assumption and y-acyclic schemes.For such database schemes we carefully compare the essence of join paths with the unique minimal Do-connection, and the result of the modified GYOreduction.For universal relation views based on such schemes the DURST window functions are essentially optimized.