Consistency check: 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.