The Data Modeling Tool allows groupings of entity types and their relationships. These groupings are called Subject Areas (SUBJECT_AREA). A subject area can also include many other subject areas.
Within a Subject Area are many entity types (ENTITY_TYPE). Each entity type can be partitioned into many partitionings (PARTITIONING). Each partitioning consists of many subtypes (ENTITY_SUBTYP). A classifier (CLASSIFIER) associates the partitioning with its classifying attribute.
Each entity type or subtype can contain many attributes (ATTRIBUTE). An attribute can serve as an identifier (IDENTIFIER, ATTR_IDENT) for its parent entity type or subtype. Each attribute can be permitted only certain values, which are known as permitted values (PERMIT_VALUE).
For entity types, subtypes, and attributes, alternate names can be documented. The alternate name is called an alias (ALIAS).
Relationships exist between entity types/subtypes. RELATIONSHIP provides the from and to entity type/subtype, the names of the from and to relationship, and the properties of the from relationship.
Relationships occur in pairs. For example, there is a row for customer places order and a row for order is placed by customer. Relationships can serve as identifiers (IDENTIFIER, REL_IDENT) for entity type/subtypes.
REL_MUTL_EXCL specifies the mutually exclusive relationships of an entity type/subtype. If there are n relationships from an entity type/subtype that are mutually exclusive, then there will be n rows in this table with the same MODEL_ID, ID, and ENTITY_ID. The Relationship_ID in each of these n rows will correspond to the n mutually exclusive relationships. Join RELATIONSHIP_ID with ID of RELATIONSHIP to retrieve the properties.
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