Modern Database Management - Chapter 3

disjointedness constraint

A ________ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes.

completeness

A ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype.

universal data model.

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

data profiling.

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

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

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

utilize all business rules that come with the packaged data model.

All of the following are steps to using a packaged data model EXCEPT:

none of the above.

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

all of the above.

An entity cluster can be formed by:

a set of one or more entity types and associated relationships grouped into a single abstract entity type.

An entity cluster is:

only one supertype.

In a supertype/subtype hierarchy, each subtype has:

supertypes

In a supertype/subtype hierarchy, subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ________ in the hierarchy.

total specialization and overlap

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

M:N relationships

In packaged data models, strong entities always have ________ between them.

require customization.

Packaged data models:

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

Subtypes should be used when:

disjoint

The ________ rule specifies that an entity can be a member of only one subtype at a time.

partial specialization

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype.

total specialization

The ________ rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship.

overlap

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

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

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

generalization.

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

specialization.

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

attribute inheritance.

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

overlap rule.

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

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

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

essential components and structures are already defined.

Using a packaged data model, projects take less time and cost because:

entities.

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

Total specialization

Which of the following is a completeness constraint?

Supertype

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