A Temporal Relational and Object Relational Database Design Technique

The NIAM (Nijssen’s Information Analysis Methodology) conceptual schema model was originated in the 1970s and later became more popular under a new name ORM (Object Role Model). It is a fact-based conceptual schema model that can be represented by graphical diagrams or described by a formal natural language. Since all relationship types are elementary, they cannot be further decomposed. This property enables the ORM conceptual schema diagram to be transformed into 5NF relational database schemas. This paper presents temporal database application development using TORM, a temporal extension to the ORM conceptual schema model. The notions of valid time and life span are introduced to the entity type and fact type concepts. An implementation of a TORM conceptual schema on relational and object relational database schemas are also presented.