Exam 2: Chapter 3 questions
3) Given the following entities, which of the choices below would be the most complicated? Automobile: VIN, EngineSize, NumberOfDoors, NumberOfPassengers, FuelType, Transmission SUV: VIN, EngineSize, NumberOfPassengers, NoWheelDrive, FuelType, Transmission Truck: VIN, EngineSize, NoWheelDrive, FuelType, Transmission, Payload A) Define one vehicle entity type to hold all entities. B) Define a separate entity type for each entity. C) Define a supertype called vehicle and make each of the entities subtypes. D) Keep only the Truck entity type.
Answer: A LO: 3.2: Recognize when to use supertype/subtype relationships in data modeling. Difficulty: Easy Classification: Concept AACSB: Information Technology
4) Subtypes should be used when: A) there are attributes that apply to some but not all instances of an entity type. B) supertypes relate to objects outside the business. C) the instances of a subtype do not participate in a relationship that is unique to that subtype. D) a recursive relationship is needed.
Answer: A LO: 3.2: Recognize when to use supertype/subtype relationships in data modeling. Difficulty: Easy Classification: Concept AACSB: Information Technology
17) A ________ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes. A) disjointness constraint B) disjoint rule C) partial specialization D) total specialization
Answer: A LO: 3.4: Specify both completeness constraints and disjointness constraints in modeling. Difficulty: Easy Classification: Concept AACSB: Information Technology
37) Which of the following is true of packaged data models? A) Relationships are connected to the highest-level entity type in an order that makes sense. B) All subtype/supertype relationships follow the total specialization and disjoint rules. C) No entities on the many sides of a relationship can be weak. D) All weak entities are considered strong.
Answer: A LO: 3.7: Explain the major features and data modeling structures of a universal (packaged) data model. Difficulty: Difficult Classification: Concept AACSB: Information Technology
2) Which of the following is a generic entity type that has a relationship with one or more subtypes? A) Megatype B) Supertype C) Subgroup D) Class
Answer: B LO: 3.1: Define key terms. Difficulty: Easy Classification: Concept AACSB: Information Technology
16) The ________ rule specifies that an entity can be a member of only one subtype at a time. A) exclusion B) disjoint C) removal D) inclusion
Answer: B LO: 3.4: Specify both completeness constraints and disjointness constraints in modeling. Difficulty: Easy Classification: Concept AACSB: Information Technology
36) Packaged data models: A) are ready to use right out of the box. B) require customization. C) allow partial specialization. D) cannot be used for most applications
Answer: B LO: 3.7: Explain the major features and data modeling structures of a universal (packaged) data model. Difficulty: Easy Classification: Concept AACSB: Information Technology
35) An entity cluster can be formed by: A) deleting a supertype and its subtype. B) combining metadata. C) combining a strong entity and its weak entities. D) deleting metadata.
Answer: C LO: 3.6: Develop an entity cluster to simplify presentation of an E-R diagram. Difficulty: Easy Classification: Concept AACSB: Information Technology
1) The property by which subtype entities possess the values of all attributes of a supertype is called: A) hierarchy reception. B) class management. C) multiple inheritance. D) attribute inheritance.
Answer: D LO: 3.1: Define key terms. Difficulty: Moderate Classification: Concept AACSB: Information Technology
48) A subtype is a generic entity that has a relationship with one or more entities at a lower level
Answer: FALSE LO: 3.1: Define key terms. Difficulty: Easy Classification: Concept AACSB: Information Technology
50) A member of a subtype does NOT necessarily have to be a member of the supertype.
Answer: FALSE LO: 3.1: Define key terms. Difficulty: Moderate Classification: Concept AACSB: Information Technology
77) Packaged data models use an entity type to store union data.
Answer: FALSE LO: 3.7: Explain the major features and data modeling structures of a universal (packaged) data model. Difficulty: Moderate Classification: Concept AACSB: Information Technology
49) An entity instance of a subtype represents the same entity instance of the supertype.
Answer: TRUE LO: 3.1: Define key terms. Difficulty: Moderate Classification: Concept AACSB: Information Technology
74) An entity cluster should focus on some area of interest to some community of users, developers, or managers.
Answer: TRUE LO: 3.6: Develop an entity cluster to simplify presentation of an E-R diagram. Difficulty: Moderate Classification: Concept AACSB: Information Technology
75) An entity cluster can have a relationship with another entity cluster much the same way that an entity can have a relationship with another entity.
Answer: TRUE LO: 3.6: Develop an entity cluster to simplify presentation of an E-R diagram. Difficulty: Moderate Classification: Concept AACSB: Information Technology
76) Packaged data models are meant to be customized.
Answer: TRUE LO: 3.7: Explain the major features and data modeling structures of a universal (packaged) data model. Difficulty: Easy Classification: Concept AACSB: Information Technology
78) A universal data model is a generic or template data model that can be reused as a starting point for a data modeling project.
Answer: TRUE LO: 3.7: Explain the major features and data modeling structures of a universal (packaged) data model. Difficulty: Moderate Classification: Concept AACSB: Information Technology
