An extended NIAM conceptual schema model for object databases

The NIAM conceptual schema model that shows the distinction between entity types and label types. In its original form, NIAM emphasises the use of external identifiers for entity types. The unique identifiers and other label types are transformed into attributes of relational database schemata. There are well-defined algorithms that transform a NIAM conceptual schema to the fifth normal form relational database schemata. This is possible because the NIAM model shows fact types and reference types some of which can be transformed into relationships between attributes. This paper presents ENIAM, an extension to NIAM which is suitable to be implemented on object databases. It introduces new concepts of category type, the main schema and sub schemas together with a transformation algorithm from an ENIAM conceptual schema into object database schema.