Chapter 5 Multiple Choice

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asdf Quiz on Chapter 5 Multiple Choice, created by . . on 15/09/2016.
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Resource summary

Question 1

Question
1. The extended entity relationship model (EERM) is sometimes referred to as the ____.
Answer
  • A) entity relationship model
  • B) enhanced entity relationship model
  • C) entity clustering relationship model
  • D) extended entity relationship diagram

Question 2

Question
2. ____ is a generic entity type that is related to one or more entity subtypes.
Answer
  • A) A subtype discriminator
  • B) Inheritance
  • C) A specialization hierarchy
  • D) An entity super type

Question 3

Question
3. The ____ depicts the arrangement of higher-level entity super types (parent entities) and lower-level entity subtypes (child entities).
Answer
  • A) subtype discriminator
  • B) inheritance
  • C) specialization hierarchy
  • D) entity super type

Question 4

Question
4. Within a specialization hierarchy, every subtype can have ____ super type(s) to which it is directly related.
Answer
  • A) zero
  • B) only one
  • C) one or many
  • D) many

Question 5

Question
5. A specialization hierarchy can have ____ level(s) of super type/subtype relationships.
Answer
  • A) zero
  • B) only one
  • C) one or many
  • D) many

Question 6

Question
6. The property of ____ enables an entity subtype to inherit the attributes and relationships of the super type.
Answer
  • A) subtype discriminator
  • B) inheritance
  • C) specialization hierarchy
  • D) entity super type

Question 7

Question
7. One important inheritance characteristic is that all entity subtypes inherit their ____ key attribute from their super type.
Answer
  • A) primary
  • B) natural
  • C) foreign
  • D) surrogate

Question 8

Question
8. At the implementation level, the super type and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.
Answer
  • A) self-referencing
  • B) 1:1
  • C) 1:M
  • D) M:N

Question 9

Question
9. A(n) ____ is the attribute in the super type entity that determines to which entity subtype each super type occurrence is related.
Answer
  • A) subtype discriminator
  • B) inheritance discriminator
  • C) specialization hierarchy
  • D) entity super type

Question 10

Question
10. The default comparison condition for the subtype discriminator attribute is the ____ comparison.
Answer
  • A) not equality
  • B) less than
  • C) greater than
  • D) equality

Question 11

Question
11. Non-overlapping subtypes are subtypes that contain a(n) ____ subset of the super type entity set.
Answer
  • A) entity
  • B) subtypes
  • C) unique
  • D) nonunique

Question 12

Question
12. Overlapping subtypes are subtypes that contain ____ subsets of the super type entity set.
Answer
  • A) entity
  • B) subtypes
  • C) unique
  • D) nonunique

Question 13

Question
13. Partial completeness is symbolized by ____.
Answer
  • A) a dotted line
  • B) two dashed lines
  • C) a circle over a single line
  • D) a circle over a double line

Question 14

Question
14. ____ is the bottom-up process of identifying a higher-level, more generic entity super type from lower-level entity subtypes.
Answer
  • A) Specialization
  • B) Generalization
  • C) Partial completeness
  • D) Total completeness

Question 15

Question
15. An entity cluster is formed by combining multiple interrelated entities into ____.
Answer
  • A) a single abstract entity object
  • B) multiple abstract entity object
  • C) a single entity object
  • D) multiple entity objects

Question 16

Question
16. The most important characteristic of an entity is its ____ key, used to uniquely identify each entity instance.
Answer
  • A) primary
  • B) natural
  • C) foreign
  • D) surrogate

Question 17

Question
17. A ____ key is a real-world, generally accepted identifier used to uniquely identify realworld objects.
Answer
  • A) primary
  • B) natural
  • C) foreign
  • D) surrogate

Question 18

Question
18. If one exists, a data modeler uses a ____ as the primary key of the entity being modeled.
Answer
  • A) foreign key
  • B) combination key
  • C) surrogate key
  • D) natural identifier

Question 19

Question
19. The primary key's main function is to uniquely identify a(n) ____ within a table.
Answer
  • A) attribute
  • B) entity instance or row
  • C) entity subtype
  • D) natural identifier

Question 20

Question
20. Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed only once in the ____relationship.
Answer
  • A) 0:1
  • B) 1:1
  • C) 1:M
  • D) M:N

Question 21

Question
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.
Answer
  • A) unique values
  • B) nonintelligent
  • C) preferably single-attribute
  • D) security complaint

Question 22

Question
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.
Answer
  • A) unique values
  • B) nointelligent
  • C) preferably single-attribute
  • D) security complaint

Question 23

Question
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.
Answer
  • A) unique values
  • B) nonintelligent
  • C) preferably single-attribute
  • D) security complaint

Question 24

Question
24. Surrogate primary keys are especially helpful when there is no ____ key.
Answer
  • A) primary
  • B) natural
  • C) foreign
  • D) composite

Question 25

Question
25.____ keys work with primary keys to properly implement relationships in the relational model.
Answer
  • A) foreign
  • B) composite
  • C) natural
  • D) surrogate

Question 26

Question
26. The preferred placement for a foreign key when working with a 1:1 relationship is to ____.
Answer
  • A) use the same primary key for both entities
  • B) create a bridge entity
  • C) place a foreign key in one of the entities
  • D) place a foreign key in both entities

Question 27

Question
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 ____.
Answer
  • A) one side is mandatory and the other side is optional
  • B) one side participates in another relationship
  • C) both sides are optional
  • D) both sides are mandatory

Question 28

Question
28.____ data refer to data whose values change over time and for which you must keep a history of the data changes.
Answer
  • A) time-sensitive
  • B) time-variant
  • C) Historical
  • D) Change-based

Question 29

Question
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.
Answer
  • A) surrogate primary keys
  • B) time-variant data
  • C) design trap
  • D) fan trap

Question 30

Question
30.____ relationships occur when there are multiple relationship paths between related entities.
Answer
  • A) redundant
  • B) duplicated
  • C) time-variant
  • D) super type

Question 31

Question
31. According to the data modeling checklist, ____ should clearly define participation and cardinality rules.
Answer
  • A) entities
  • B) naming conventions
  • C) relationships
  • D) attributes
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