Consistency Checks: Variants 

Completeness

A data model is complete if it contains neither inconsistent relationships nor inconsistent specializations.

Relationships and specializations are inconsistent if their source entity types do not belong to the data model.

 

Existence of Predecessors

The predecessors of a data model exist if there are neither inconsistent relationships nor inconsistent specializations.

Relationships and specializations are considered as inconsistent in this check if their source entity types do not exist.

 

Connectivity

A data model is connective if all the entity types of the data model are connected.

All the entity types of a data model are connective if there is a path connecting each entity type of the data model to each other entity type of the data model. These paths are either relationships or specializations.

A data model is not connective if the set of entity types making up the data model disintegrates into several unconnected subsets. Each of these subsets, however, is in itself connective.

If the number of subsets in the check log is greater than 1, the data model is not connective.

 

Existence of Hierarchy Objects

All the objects of a hierarchy exist if there are neither inconsistent data models nor inconsistent entity types among the objects of this hierarchy.

Data models and entity types are inconsistent in this check if they are referenced in the hierarchy but do not exist.