| Term | Definition |
|---|
| Enhanced entity-relationship (EER) model | The model that has resulted from extending the original E-R model with new modeling constructs. |
| Subtype | A subgrouping of the entities in an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other subgroupings. , A subgrouping of the entities in an entity type that has attributes distinct from those in other subgroupings |
| Supertype | A generic entity type that has a relationship with one or more subtypes |
| Attribute inheritance | A property by which subtype entities inherit and stances of all relationships of the supertype. |
| Generalization | The process of defining a more general entity type from a set of more specialized entity types. |
| Specialization | The process of defining one ore more subtypes of the supertype and forming supertupe/subtype relationships. |
| Completeness constraint | A type of constraint that addresses the question whether an instance of a supertype must also be a member of at least one subtype. |
| Total specialization rule | Specifies that each entity instance of the supertype must be a member of some subtype in the relationship. |
| Partial specialization rule | Specifies that an entity instance of the supertype is allowed not to belong to any subtype. |
| Disjointness constraint | A constraint that addresses the question whether an instance of a supertype may simultaneously be a member of two (or more) subtypes. |
| Disjoint rule | Specifies that if an entity instance (of the supertype) is a member of one subtype, it cannot simultaneously be a memeber of any other subtype. |
| Overlap rule | Specifies that an entity instance can simultaneously be a member of two (or more) subtypes. |
| Subtype discriminator | the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related (p187) |
| Supertype/subtype hierarchy | A hierarchical arrangement and subtypes, where each subtype has only one supertype. |
| Entity cluster | A set of one or more entity types and associated relationship grouped into a single abstract entity type. |
| Universal data model | A generic or template data model that can be reused as a starting point for a data modeling project. |
| Derivation | A statement derived from other knowledge in the business |
| Action assertion | A statement of a constraint or control on the actions of the organization. |
| Structural assertion | A statment that expresses some aspect of the static structure of the organization. |
| Derived fact | A fact is derived from business rules using an algorithm or inference |
| Anchor object | A business rule (a fact) on which actions are limited. |
| Action | An operation, such as create. delete, update, or read, which may be performed on data object. |
| Corresponding object | A business rule (a fact) that influences the ability to perform an action on another business rule. |
Combine with other sets
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