Topic 3

The property by which subtype entities possess the values of all attributes of a supertype is called:

• hierarchy reception.

• class management.

• multiple inheritance.

• attribute inheritance.

Which of the following is a generic entity type that has a relationship with one or more subtypes?

• Megatype

• Supertype

• Subgroup

• Class

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

• Define one vehicle entity type to hold all entities.

• Define a separate entity type for each entity.

• Define a supertype called vehicle and make each of the entities subtypes.

• Keep only the Truck entity type.

Subtypes should be used when:

• there are attributes that apply to some but not all instances of an entity type.

• supertypes relate to objects outside the business.

• the instances of a subtype do not participate in a relationship that is unique to that subtype.

• a recursive relationship is needed.

In the figure below, which of the following apply to both OUTPATIENTs and RESIDENT_PATIENTs?

• Checkback_Date

• Date_Discharged

• Patient_Name

• XML

In the figure below, which of the following is a subtype of patient?

• Outpatient

• Physician

• Bed

• Date_Hired

The process of defining one or more subtypes of a supertype and forming relationships is called:

• specialization.

• generalization.

• creating discord.

• selecting classes.

In the figure below, to which of the following entities are the entities "CAR" and "TRUCK" generalized?

• Make

• Vehicle

• Model

• Price

The process of defining a more general entity type from a set of more specialized entity types is called:

• generalization.

• specialization.

• normalization.

• extrapolation.

The following figure is an example of:

• partial specialization.

• completeness.

• total specialization.

• disjointness.