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Q:

When mapping a supertype/subtype relationship which of the following is true?

A) The supertype primary key is assigned to each subtype. B) The subtype primary key is assigned to each supertype.
C) There is no link between the supertype/subtype entities. D) There is no primary key/foreign key relationship between a supertype/subtype.
 
Answer & Explanation Answer: A) The supertype primary key is assigned to each subtype.

Explanation:
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Q:

 When an entity instance may be a member of multiple subtypes or it does not have to be a member of a subtype, it is which of the following?

A) Disjoint with total specialization B) Disjoint with partial specialization
C) Overlap with total specialization D) Overlap with partial specialization
 
Answer & Explanation Answer: C) Overlap with total specialization

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Q:

 A supertype/subtype hierarchy has which of the following features?

A) Subtypes at the lower lever in the hierarchy inherit attributes only from their immediate supertype. B) Subtypes at the higher lever in the hierarchy inherit attributes only from their immediate subtype.
C) Attributes are assigned at the highest logical level. D) Attributes are assigned at the lowest logical level.
 
Answer & Explanation Answer: C) Attributes are assigned at the highest logical level.

Explanation:
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