Exam 5: Advanced Data Modeling

Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype.

____ is the bottom-up process of identifying a higher-level,more generic entity supertype from lower-level entity subtypes.

If one exists,a data modeler uses a ____ as the primary key of the entity being modeled.

The main concern with redundant relationships is that they remain ____________________ across the model.

____ relationships occur when there are multiple relationship paths between related entities.

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

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

Non-overlapping subtypes are subtypes that contain a(n)____ subset of the supertype entity set.

The preferred placement for a foreign key when working with a 1:1 relationship is to ____.

____________________ completeness means that every supertype occurrence must be a member of at least one subtype.

The "____" characteristic of a primary key states the following: The PK should not have embedded semantic meaning.An attribute with embedded semantic meaning is probably better used as a descriptive characteristic of the entity rather than as an identifier.

The entity supertype contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.

The most common design trap is known as a(n)____________________.

Subtypes that contain nonunique subsets of the supertype entity set are known as ____________________ .

When selecting a foreign key placement for a 1:1 relationship,place the PK of the entity on the mandatory side in the entity on the optional side as a FK,and make the FK mandatory when ____.

Entity subtypes do not inherit the relationships in which the supertype entity participates.

Surrogate primary keys are especially helpful when there is no ____ key.

A ____ occurs when you have one entity in two 1:M relationships to other entities,thus producing an association among the other entities that is not expressed in the model.

Specialization is based on grouping ____________________ characteristics and relationships of the subtypes.

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