Advanced Data Modeling, Chapter 6

The ____ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.
1. specialization
2. uniqueness
3. inheritance
4. completeness
In addition to the normal behavior, the EER model also supports specialization ____ where a subtype can have multiple parents (supertypes).
1. nets
2. networks
3. lattices
4. webs
____ relationships occur when there are multiple relationship paths between related entities.
1. Shared
2. Redundant
3. Joined
4. Nonkey
A specialization hierarchy reflects the ____ relationship between EMPLOYEE and its subtypes.
1. 1:1
2. 1:*
3. *:*
4. 0:*
A(n) ____ trap occurs when a relationship is improperly or incompletely identified and, therefore, is represented in a way that is not consistent with the real world.
1. entity
2. relationship
3. key
4. design
In modeling terms, the ____ contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.
1. entity supertype
2. superentity
3. base entity
4. higher entity
The property of ____ enables an entity subtype to inherit the attributes and relationships of the supertype.
1. specialization
2. generalization
3. inheritance
4. uniqueness
The implementation of disjoint subtypes is based on the value of the subtype discriminator attribute in the ____.
1. supertype
2. subtype
3. primary key attribute
4. foreign key attribute
The ____'s function is to guarantee entity integrity.
1. entity name
2. discriminator
3. index
4. primary key
What is the best data type for a primary key?
1. numeric
2. text
3. boolean
4. date
____ data refer to data whose values change over time and for which you must keep a history of the data changes.
1. Closed
2. Historical
3. Time-complete
4. Time-variant
Arguably, the most important characteristic of an entity is its ____.
1. name
2. primary key
3. relationships
4. attributes
____ subtypes are subtypes that contain nonunique subsets of the supertype entity set.
1. Shared
2. Overlapping
3. Joined
4. Complex
One important inheritance characteristic is that all entity subtypes inherit their ____ from their supertype.
1. indexes
2. foreign keys
3. candidate keys
4. primary key attribute
____ is the bottom-up process of identifying a higher-level, more generic entity supertype from lower-level entity subtypes.
1. Discrimination
2. Specialization
3. Completeness
4. Generalization
As part of database naming conventions, attribute names should use suffixes such as _ID, _NUM, or _CODE for the ____ attribute.
1. primary key
2. foreign key
3. index
4. determinant
The EER model builds on ER concepts and adds support for entity supertypes, subtypes, and entity ____.
1. clustering
2. housing
3. joining
4. extension
A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.
1. inheritance key
2. subtype discriminator
3. supertype selector
4. subtype entity
____________ is used when an entity is composed of (or is formed by) a collection of other entities, but the entities are independent of each other. That is, the relationship can be classified as a ‘has_a’ relationship type.
1. Specialization
2. Generalization
3. Aggregation
4. Composition
__________ is used when when two entities are associated in an aggregation association with a strong identifying relationship and deleting the parent deletes the children instances.
1. Specialization
2. Generalization
3. Clustering
4. Composition

Advanced Data Modeling, Chapter 6

Quiz