DAT 380 Wk 3 – Practice: Knowledge Check

Repeating groups must be eliminated by ensuring that each row defines a single entity.

True

False

The purpose of an entity _____ is to simplify an entity-relationship diagram (ERD) and thus enhance its readability.

Within a specialization hierarchy, every subtype can have _____ supertype(s) to which it is directly related.

A subtype contains attributes that are common to all of its supertypes.

In the context of total completeness, in a(n) _____, every supertype occurrence is a member of only one subtype.

foreign key constraint

nonunique constraint

overlapping constraint

disjoint constraint

A table that is in 2NF and contains no transitive dependencies is said to be in _____.

To model time-variant data, one must create a new entity in an M:N relationship with the original entity.

In a _____ situation, one key determines multiple values of two other attributes and those attributes are independent of each other.

transitive dependency

multivalued dependency

functional dependency

partial dependency

One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their supertype.

One important inheritance characteristic is that all entity subtypes inherit their _____ key attribute from their supertype.