Exam 5: Advanced Data Modeling

____ data refer to data whose values change over time and for which you must keep a history of the data changes.

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

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

____________________ completeness means that not every supertype occurrence is a member of a subtype.

The primary key's main function is to uniquely identify a(n)____ within a table.

Overlapping subtypes are subtypes that contain ____ subsets of the supertype entity set.

In what two cases are composite primary keys particularly useful?

Composite primary keys are particularly useful as identifiers of composite entities,where each primary key combination is allowed only once in the ____ relationship.

The completeness constraint can be partial or total.

At the implementation level,the supertype and its subtype(s)depicted in the specialization hierarchy maintain a 1:1 relationship.