What rule specifies that an entity instance can simultaneously be a member of two or more subtypes?

What is an entity that exists independently of other entity types?

An example of a term would be the following sentence: "A student registers for a course."

False - This would be a fact.

Which of the following criteria should be considered when selecting an identifier?
Choose a null identifier.
  Choose the most complex identifier possible.
  Choose an identifier that is not stable.
  Choose an identifier that doesn't have large composite attributes.

Choose an identifier that doesn't have large composite attributes.

Data, rather than processes, are the most complex aspects of many modern information systems.

The E-R model is used to construct a conceptual model.

The most common types of entities are:

A fact is an association between two or more terms.

The name used for an entity type should never be the same in other E-R diagrams on which the entity appears.

An attribute that can be calculated from related attribute values is called a ______ attribute.

A mutually exclusive relationship is one in which:

An entity instance can participate in only one of several alternative relationships.

Which of the following is NOT a good characteristic of a data name?
Relates to business characteristics
  Readable
  Repeatable
  Relates to a technical characteristic of the system

Relates to a technical characteristic of the system.

The logical representation of an organization's data is called a(n):

Entity-Relationship Model

The degree of a relationship is the number of attributes that are associated with it.

Business rules are formulated from a collection of business ramblings.

A fact is an association between two or more:

Data names should always relate to business characteristics.

An entity type name should be all of the following EXCEPT:
specific to the organization.
  as short as possible.
  concise.
  a singular noun.

A value that indicates the date or time of a data value is called a:

An entity that associates the instances of one or more entity types and contains attributes specific to the relationship is called a(n):

Some examples of attributes are: eye_color, weight, student_id, STUDENT.

False - STUDENT is an entity name.

A business rule is a statement of how a policy is enforced or conducted.

A simple attribute can be broken down into smaller pieces.

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

Disjointedness Constraint

A member of a subtype does NOT necessarily have to be a member of the supertype.

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.

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

The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype, it MUST simultaneously be a member of another subtype.

Generalization is a top-down process.

Mapping existing data to new data in a packaged data model is useful for developing migration plans.

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.

You will never need to map data in current databases to data in a packaged model.

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

Regardless of the business situation, a member of the supertype is always a member of more than one subtype.

Entity clustering is a methodology for grouping one or more entity types and associated relationships into a single abstract entity type.

Which of the following is a completeness constraint?
  Total recall
  Partial hybridization
  Partial generalization
  Total specialization

In packaged data models, all subtype\supertype relationships follow the ______ and _____ rules.

Total Specialization; Overlap

An entity cluster should focus on some area of interest to some community of users, developers, or managers.

Data models of an existing database are harder for data modelers to read.

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

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

Which of the following is true of packaged data models?
  All weak entities are considered strong.
  Relationships are connected to the highest-level entity type in an order that makes sense.
  All subtype/supertype relationships follow the total specialization and disjoint rules.
  No entities on the many sides of a relationship can be weak.

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

All of the following are advantages of packaged data models EXCEPT:
  projects take less time and cost less.
  packaged data models can be built using proven components evolved from cumulative experiences.
  more one-to-one relationships give the data model more flexibility.
  the data model is easier to evolve.

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

A _______ specifies the number of instances of one entity that can be associated with each instance of another entity.

A cardinality constraint tells what kinds of properties are associated with an entity.

The intent of a business rule is to break down business structure.

The number of entity types that participate in a relationship is called the:

The relationship between a weak entity and its owner is an identifying relationship.

A property or characteristic of an entity type that is of interest to the organization is called a(n):

One of the roles of a database analyst is to identify and understand rules that govern data.

An attribute that can be broken down into smaller parts is called a(n) _______ attribute.

A multivalued attribute may take on more than one value for a particular entity instance.

The relationship among the instances of three entity types is called a unary relationship.

When systems are automatically generated and maintained, quality is diminished.

An attribute that must have a value for every entity (or  relationship) instance is a:

An attribute that can be calculated from related attribute values is called a ______ attribute.

While business rules are not redundant, a business rule can refer to another business rule.

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

Essential components and structures are already defined.

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

When subtypes are overlapping, an additional field must be added to the supertype to act as a discriminator.

When the total specialization rule is set for a supertype/subtype relationship, one could roughly compare the supertype to an abstract class in object-oriented programming.

It is easier to share information across organizations if companies in the same industry use the same universal data model as the basis for their organizational databases.

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

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

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

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

You will never need to map data in current databases to data in a packaged data model.

The overlap rule specifies that if an entity instance of the supertype is a member of one subtype, it can simultaneously be a member of two (or more) subtypes.

Is the rule that specifies that an entity instance of a supertype may not simultaneously be a member of two or more subtypes?

Is a generic entity type that has a relationship with one or more subtypes?

What type of constraints in Supertype that an instance of a supertype may simultaneously be a member of two or more subtypes?

Which of the following specifies that an entity instance of the supertype does not have to belong to any subtype?