In the context of total completeness,in a(n),every supertype occurrence is a member of at least one subtype.
A)Unique constraint
B)disjoint constraint
C)overlapping constraint
D)foreign key constraint

Question

Quizplus · Accepted Answer

Total completeness refers to the rule that every occurrence of the supertype must be a member of at least one subtype. In overlapping constraint, an entity can be a member of multiple subtypes simultaneously, which ensures that every supertype occurrence is a member of at least one subtype. Therefore, option C, overlapping constraint is the correct choice. Unique constraint (A) refers to a rule that ensures that each value in a column of a table is unique. Disjoint constraint (B) refers to a rule where an entity can only belong to one subtype at a time. Foreign key constraint (D) refers to a rule where a foreign key value in a table must match a primary key value in another table.

In the Context of Total Completeness,in A(n),every Supertype Occurrence Is