Exam 5: Advanced Data Modeling

From a data modeling point of view, _____ data refer to data whose values change over time and for which one must keep a history of the data changes.

Overlapping subtypes are subtypes that contain a unique subset of the supertype entity set.

The "_____" characteristic of a primary key states that the primary key should not have embedded semantic meaning.

The default comparison condition for the subtype discriminator attribute is the _____ comparison.

A(n) _____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

A _____ key is a real-world, generally accepted identifier used to uniquely identify real-world objects.

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

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

Differentiate between specialization and generalization.

Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed _____ in the M:N relationship.

A partial completeness constraint is represented by _____.

A total completeness constraint is represented by a _____.

While using a surrogate key, one must ensure that the candidate key of the entity in question performs properly through the use of the "_____" and "not null" constraints.

In which two cases are composite primary keys particularly useful?

Composite keys are useful as identifiers of weak entities, where the weak entity has a strong _____ relationship with the parent entity.

An entity supertype can have disjoint or overlapping entity subtypes.

Within a specialization hierarchy, a supertype can exist only within the context of a subtype.

Which of the following is a specialization hierarchy disjoint constraint scenario in case of partial completeness?

_____ keys work with primary keys to properly implement relationships in the relational model.

The property of _____ enables an entity subtype to inherit the attributes and relationships of the supertype.