Abstrakt
In recent years, many so-called multi-model database management systems have emerged, mainly as extensions of the existing single-model systems, regardless they used to be relational or NoSQL. These new database systems make new demands on their users.
From the point of view of the conceptual and logical representation, the so far widely used approaches, especially ER and UML, prove not to be sufficient enough in many aspects due to the specific properties of multi-model data. In addition, it is also difficult to query data that is represented in various and often overlapping data models at the logical level.