Tuesday, January 19, 2010
An attribute of a binary relationship type can be migrated to become an attribute of one of the participating entity types.
The attributes of 1:1 or 1:N relationship types can be migrated to one of the participating entity types. In case of 1:1 cardinality, attribute can be moved to either of entity types in binary relationship and in case of 1:N cardinality attributes can be migrated only to N side of relationship. In both 1:1 and I:N relationship types, the decision as to where a relationship attribute should be placed-as a relationship type attribute or as an attribute of a participating entity type-is determined subjectively by the schema designer. For relationship types with cardinality M:N, attributes cannot be migrated to become attributes of one of participating entity types.