Data models

Underlying the structure of a database is a data model, a collection of conceptual tools for describing the real-world entities to be modeled in the database and the relationships among those entities. Data models differ in the primitives available for describing data and in the amount of semantic detail that can be expressed. The various data models proposed fall into 3 different groups: object-based logical models, record-based logical models, and physical data models. Recently a new model, the object-relational model, has been developed. It merges the object-oriented data model with the dominant record-based model, the relational model. This model is briefly examined.