Abstract. In the past, numerous ways have been presented of mapping Object Role Modeling (ORM) conceptual schemas to relational logical schemas. However, mapping to hierarchical logical schemas has received little attention. This is unfortunate, since hierarchical logical schemas can be used to acquire physical schemas, like hierarchical DDL or XSD documents, along the lines of a three-level data modeling architecture. Given that hierarchical databases still exist abundantly in industrial practice, mapping ORM conceptual schemas to hierarchical logical schemas can be very relevant. A meta model description of a hierarchical logical data model offers a formal basis for defining such a mapping. We note that a hierarchical logical data model, as well as a meta model to which it should conform, is often described only informally in literature, particularly lacking a formal meta model specification. In this paper, we present a formal specification of a meta hierarchical logical data model using ORM.
Robert Schmaal, European Space Research and Technology Centre (The Netherlands)