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- Question
When an entity instance must be a member of only one subtype, it is which of the following?
Options- A. Disjoint with total specialization
- B. Disjoint with partial specialization
- C. Overlap with total specialization
- D. Overlap with partial specialization
- Correct Answer
- Disjoint with total specialization
- 1. Inheritance is which of the following?
Options- A. When a supertype entity inherits values of the subtype attribute
- B. When a subtype entity inherits values of the supertype attribute
- C. When a supertype entity inherits values of another supertype attribute
- D. When a subtype entity inherits values of another subtype attribute Discuss
- 2. Use of a supertype/subtype relationship is necessary when which of the following exists?
Options- A. An instance of a subtype participates in a relationship that is unique to that subtype.
- B. An instance of a subtype participates in a relationship that is the same as the other subtypes.
- C. Attributes apply to all of the instances of an entity type.
- D. No attributes apply to any of the instances of an entity type. Discuss
- 3. A subtype discriminator is which of the following?
Options- A. An attribute of the supertype whose values determine the subtype
- B. An attribute of the subtype whose values determine the supertype
- C. An attribute of the supertype whose values determine the supertype
- D. An attribute of the subtype whose values determine the subtype Discuss
- 4. A supertype/subtype hierarchy is which of the following?
Options- A. Each subtype has only one attribute.
- B. Each supertype has only one attribute.
- C. Each subtype has only one supertype.
- D. Each supertype has only one subtype. Discuss
- 5. Which one of the following symbols is not used in an ERD?
Options- A. Rectangle
- B. Oval
- C. Diamond
- D. Circle Discuss
- 6. A rectangle represents which of the following in an EER?
Options- A. Attribute
- B. Entity
- C. Optional One
- D. Relationship Discuss
- 7. Specialization is which of the following processes?
Options- A. Defining one or more subtypes of the supertype and forming supertype/subtype relationships.
- B. Defining one or more supertypes of the subtype and forming supertype/subtype relationships.
- C. Defining one or more subtypes of the supertype and not forming supertype/subtype relationships.
- D. Defining one or more supertypes of the subtype and not forming supertype/subtype relationships. Discuss
- 8. Which of the following statements concerning business rules is true?
Options- A. It should be complex.
- B. It should not be convertible to computer code.
- C. It may include restrictions.
- D. All of the above. Discuss
- 9. A secondary key is which of the following?
Options- A. Nonunique key
- B. Primary key
- C. Useful for denormalization decisions
- D. Determines the tablespace required Discuss
- 10. Selecting a data type involves which of the following?
Options- A. Maximize storage space
- B. Represent most values
- C. Improve data integrity
- D. All of the above. Discuss
ER Model and Business Rules problems
Search Results
Correct Answer: When a subtype entity inherits values of the supertype attribute
Correct Answer: An instance of a subtype participates in a relationship that is unique to that subtype.
Correct Answer: An attribute of the supertype whose values determine the subtype
Correct Answer: Each subtype has only one supertype.
Correct Answer: Circle
Correct Answer: Entity
Correct Answer: Defining one or more subtypes of the supertype and forming supertype/subtype relationships.
Correct Answer: It may include restrictions.
Correct Answer: Nonunique key
Correct Answer: Improve data integrity
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