6354126
Pregunta 1
Pregunta
1. The extended entity relationship model (EERM) is sometimes referred to as the ____.
Respuesta
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A) entity relationship model
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B) enhanced entity relationship model
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C) entity clustering relationship model
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D) extended entity relationship diagram
Pregunta 2
Pregunta
2. ____ is a generic entity type that is related to one or more entity subtypes.
Respuesta
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A) A subtype discriminator
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B) Inheritance
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C) A specialization hierarchy
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D) An entity super type
Pregunta 3
Pregunta
3. The ____ depicts the arrangement of higher-level entity super types (parent entities) and lower-level entity subtypes (child entities).
Respuesta
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A) subtype discriminator
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B) inheritance
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C) specialization hierarchy
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D) entity super type
Pregunta 4
Pregunta
4. Within a specialization hierarchy, every subtype can have ____ super type(s) to which it is directly related.
Respuesta
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A) zero
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B) only one
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C) one or many
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D) many
Pregunta 5
Pregunta
5. A specialization hierarchy can have ____ level(s) of super type/subtype relationships.
Respuesta
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A) zero
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B) only one
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C) one or many
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D) many
Pregunta 6
Pregunta
6. The property of ____ enables an entity subtype to inherit the attributes and relationships of the super type.
Respuesta
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A) subtype discriminator
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B) inheritance
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C) specialization hierarchy
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D) entity super type
Pregunta 7
Pregunta
7. One important inheritance characteristic is that all entity subtypes inherit their ____ key attribute from their super type.
Respuesta
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A) primary
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B) natural
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C) foreign
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D) surrogate
Pregunta 8
Pregunta
8. At the implementation level, the super type and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.
Respuesta
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A) self-referencing
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B) 1:1
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C) 1:M
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D) M:N
Pregunta 9
Pregunta
9. A(n) ____ is the attribute in the super type entity that determines to which entity subtype each super type occurrence is related.
Respuesta
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A) subtype discriminator
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B) inheritance discriminator
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C) specialization hierarchy
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D) entity super type
Pregunta 10
Pregunta
10. The default comparison condition for the subtype discriminator attribute is the ____ comparison.
Respuesta
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A) not equality
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B) less than
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C) greater than
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D) equality
Pregunta 11
Pregunta
11. Non-overlapping subtypes are subtypes that contain a(n) ____ subset of the super type entity set.
Respuesta
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A) entity
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B) subtypes
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C) unique
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D) nonunique
Pregunta 12
Pregunta
12. Overlapping subtypes are subtypes that contain ____ subsets of the super type entity set.
Respuesta
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A) entity
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B) subtypes
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C) unique
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D) nonunique
Pregunta 13
Pregunta
13. Partial completeness is symbolized by ____.
Respuesta
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A) a dotted line
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B) two dashed lines
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C) a circle over a single line
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D) a circle over a double line
Pregunta 14
Pregunta
14. ____ is the bottom-up process of identifying a higher-level, more generic entity super type from lower-level entity subtypes.
Respuesta
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A) Specialization
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B) Generalization
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C) Partial completeness
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D) Total completeness
Pregunta 15
Pregunta
15. An entity cluster is formed by combining multiple interrelated entities into ____.
Respuesta
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A) a single abstract entity object
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B) multiple abstract entity object
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C) a single entity object
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D) multiple entity objects
Pregunta 16
Pregunta
16. The most important characteristic of an entity is its ____ key, used to uniquely identify each entity instance.
Respuesta
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A) primary
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B) natural
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C) foreign
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D) surrogate
Pregunta 17
Pregunta
17. A ____ key is a real-world, generally accepted identifier used to uniquely identify realworld objects.
Respuesta
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A) primary
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B) natural
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C) foreign
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D) surrogate
Pregunta 18
Pregunta
18. If one exists, a data modeler uses a ____ as the primary key of the entity being modeled.
Respuesta
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A) foreign key
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B) combination key
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C) surrogate key
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D) natural identifier
Pregunta 19
Pregunta
19. The primary key's main function is to uniquely identify a(n) ____ within a table.
Respuesta
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A) attribute
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B) entity instance or row
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C) entity subtype
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D) natural identifier
Pregunta 20
Pregunta
20. Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed only once in the ____relationship.
Respuesta
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A) 0:1
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B) 1:1
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C) 1:M
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D) M:N
Pregunta 21
Pregunta
21. The “____” characteristic of a primary key states the following: The PK must uniquely identify each entity instance. A primary key must be able to guarantee unique values. It cannot contain nulls.
Respuesta
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A) unique values
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B) nonintelligent
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C) preferably single-attribute
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D) security complaint
Pregunta 22
Pregunta
22. The “____” characteristic of a primary key states the following: The selected primary key must not be composed of any attribute(s) that might be considered a security risk or violation. For example, using a Social Security number as a PK in an EMPLOYEE table is not a good idea.
Respuesta
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A) unique values
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B) nointelligent
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C) preferably single-attribute
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D) security complaint
Pregunta 23
Pregunta
23. 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.
Respuesta
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A) unique values
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B) nonintelligent
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C) preferably single-attribute
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D) security complaint
Pregunta 24
Pregunta
24. Surrogate primary keys are especially helpful when there is no ____ key.
Respuesta
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A) primary
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B) natural
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C) foreign
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D) composite
Pregunta 25
Pregunta
25.____ keys work with primary keys to properly implement relationships in the relational model.
Respuesta
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A) foreign
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B) composite
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C) natural
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D) surrogate
Pregunta 26
Pregunta
26. The preferred placement for a foreign key when working with a 1:1 relationship is to ____.
Respuesta
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A) use the same primary key for both entities
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B) create a bridge entity
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C) place a foreign key in one of the entities
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D) place a foreign key in both entities
Pregunta 27
Pregunta
27. 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 ____.
Respuesta
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A) one side is mandatory and the other side is optional
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B) one side participates in another relationship
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C) both sides are optional
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D) both sides are mandatory
Pregunta 28
Pregunta
28.____ data refer to data whose values change over time and for which you must keep a history of the data changes.
Respuesta
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A) time-sensitive
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B) time-variant
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C) Historical
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D) Change-based
Pregunta 29
Pregunta
29. 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.
Respuesta
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A) surrogate primary keys
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B) time-variant data
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C) design trap
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D) fan trap
Pregunta 30
Pregunta
30.____ relationships occur when there are multiple relationship paths between related entities.
Respuesta
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A) redundant
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B) duplicated
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C) time-variant
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D) super type
Pregunta 31
Pregunta
31. According to the data modeling checklist, ____ should clearly define participation and cardinality rules.
Respuesta
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A) entities
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B) naming conventions
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C) relationships
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D) attributes
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