Session 16 Flashcards
1
Q
Subtype
A
subgrouping of the entities in an entity type that shares common attributes or relationships distinct from other subtypes
2
Q
Supertype
A
a generic entity type that has a relationship with one or more subtype
3
Q
Total specialization
A
an entity instance of the supertype must be an instance of one of the subtypes
4
Q
Partial specialization
A
an entity instance of the supertype may or may not be an instance of one of the subtypes
5
Q
Disjoint
A
an entity instance of the supertype can be an instance of only one subtype
6
Q
Overlap
A
an entity instance of the supertype may be an instance of multiple subtypes
