Informal Introduction into the Concept-Oriented Data Model

Currently there exist many full featured data models and specific data modelling techniques which are based on different basic principles. For examples, some models are based on first order logic and predicate calculus. Other models are based on set theory. The third class of models proceeds from the separation between entities and relationships and the fourth direction for data modelling emphasizes the dominating role of elementary facts. The existing models can be distinguished also by their main goals. Some of them are targeted at data retrieval by means of declarative queries while others are mainly dealing with procedural aspects. There are models that are adapted for manipulating hierarchies while other models are more suitable for applying to flat problem domains.