Chapter 3 ITD 256

Given the following entities, which of the choices below would be the most complicated?

Define one vehicle entity type to hold all entities

Which of the following is true of packaged data models?

Relationships are connected to the highest-level entity type in an order that makes sense.

In packaged data models, all subtype/supertype relationships follow the ________ and ________ rules.

Total Specialization and Overlap

A good method for identifying inconsistencies and finding hidden meaning in the customized purchased data model is:

data profiling.

The most important challenge of customizing a purchased data model is:

determining the business rules that will be established through the data model.

When identifying the parts of the packaged data model that apply to your organization, one should first start with:

entities.

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

generalization

The third step in the data modeling process with a packaged data model is:

map data to be used from package to data in current databases.

All of the following are advantages of packaged data models EXCEPT:

more one-to-one relationships give the data model more flexibility.

The ________ rule states that an entity instance can simultaneously be a member of two (or more) subtypes.

overlap

Packaged data models:

require customization

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

specialization.

An attribute of the supertype that determines the target subtype(s) is called the:

subtype discriminator.

The subtype discriminator is a composite attribute when there is a(n):

the overlap rule

A generic or template data model that can be reused as a starting point for a data modeling project is called a(n):

universal data model