CSE :: Database System 2 - CS
- Overlapping and disjoint subtypes have different approaches on how the subtype discriminator is applied.
- An entity instance of a subtype represents the same entity instance of a supertype.
- A supertype is an entity type that shares common attributes or relationships distinct from other subgroupings.
- Total specialization is represented by double lines between the supertype and subtype on an EER.
- Generalization is the process of defining more general entity types from a set of more specialized entity types.
- It is appropriate to use a supertype/subtype relationship when there are attributes that apply to some of the instances of an entity type.
- If an entity adheres to the disjoint rule, then an entity instance can be a member of more than one entity for a given supertype.
- Action assertions have traditionally been implemented within an application program.
- An entity cluster is a set of one or more entity types and associated relationships.
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