A temporal object oriented conceptual schema model

NIAM is a fact-based conceptual schema model. It was primarily designed as a data model with a formal natural language. However, it is now a popular relational database design tool. NIAM shows clear distinction between the concept of objects and labels. Each entity type must have a unique identifier. So, it is suitable to be mapped to relational database schemas since it is based on the external identifier concept such as the primary keys. Nowadays, object-oriented databases popularity has increased. It is suitable for the representation of complex objects without external identifiers. This ability also makes it suitable for the representation of temporal data. Valid time and transaction time can be attached to attributes without any changes to the identifiers and time normalization which is required if the relational database model is used. This paper presents OONIAM, an extension to NIAM that supports the concepts of complex objects and temporal databases. The concepts of methods, main schemas and sub schemas are also introduced. A set of transformation steps from an OONIAM schema to object database schema is provided.