Exam 5: Advanced Data Modeling

A occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.

The is the result of adding more semantic constructs to the original entity relationship (ER) model.

A is a primary key created by a database designer to simplify the identification of entity instances.

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

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

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

Explain the two criteria that help a designer in determining when to use subtypes and supertypes.

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

What do specialization hierarchies do?

The specifies whether each entity supertype occurrence must also be a member of at least one subtype.

The extended entity relationship model (EERM) is sometimes referred to as the .

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

Disjoint subtypes are also known as subtypes.

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

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

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

A occurs when there is 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.

Usually, a data modeler uses a natural identifier as the of the entity being modeled, assuming that the entity has a natural identifier.

According to the "preferably single-attribute" characteristic of a primary key, the primary key:

Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype.