IS 4420 Exam 1

A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key is said to be in _____.

1NF

________________ is a software system that is used to create, maintain, and provide controlled access to user databases.

A Database Management System (DBMS)

_____ serve as the intermediary between the user and the database.

DBMSs

_____ exists when different versions of the same data appear in different places.

Data inconsistency

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

False

Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

False

Composite attributes make it easier to facilitate detailed queries.

False

Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

False

In implementation terms, an entity is existence-dependent if it has a mandatory primary key.

False

The row's range of permissible values is known as its domain.

False

_____ is the bottom-up process of identifying a higher-level, more generic entity supertype from lower-level entity subtypes.

Generalization

The conceptual model can handle _____ relationships and multivalued attributes.

M:N

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities.

M:N

__________________ are descriptions of the properties of data, including data types, data sizes, and allowable values etc. Note: the blank may represent a single word or a phrase.

Metadata

Which of the following is a specialization hierarchy disjoint constraint scenario which describes partial completeness?

Subtype discriminator can be null.

A Composite Primary Key is a Primary Key that consists of more than one attribute.

True

A database is an organized collection of logically related data.

True

Denormalization produces a lower normal form. (NOTE: 1NF is lower than 2NF, and 2NF is lower than 3NF).

True

Each row in the relational table is known as an entity instance or entity occurrence in the ER model.

True

Each table in a relational database must have a primary key.

True

In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.

True

The objective of normalization is to ensure that each table conforms to the concept of well-formed/structured relations.

True

A partial completeness constraint is represented by _____.

a single horizontal line under a circle

A(n) _____ is the equivalent of a field in a file system.

attribute

A(n) _____ is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization. Note: the blank may represent a single word or a phrase.

business rule

A _____ key can be described as a minimal superkey, a superkey without any unnecessary attributes.

candidate

An atomic attribute _____.

cannot be further subdividied

A _____ attribute can be further subdivided to yield additional attributes.

composite

A(n) _____ is a restriction placed on the data.

constraint

A total completeness constraint is represented by a _____.

double horizontal line under a circle

A(n) _____ is anything about which data are to be collected and stored.

entity

The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. This is an example of _____ integrity.

entity

In specialization hierarchies with multiple levels of supertype and subtypes, a lower-level subtype can inherit only a few of the attributes and relationships from its upper-level supertypes.

false

A _____ is the primary key of one table that has been placed into another table to create a common attribute.

foreign key

Which of the following represents data that has been processed or summarized?

information

The property of _____ enables an entity subtype to inherit the attributes and relationships of the supertype.

inheritance

Below are disadvantages of storing data in files except:

not environmentally friendly

Dependencies based on only a part of a composite primary key are known as _____ dependencies.

partial

A verb associating two nouns in a business rule translates to a(n) _____ in the data model.

relationship

A(n) _____ is bidirectional.

relationship

A relational table must not contain a(n) _____.

repeating group

A _____ attribute is one that cannot be subdivided.

simple

If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as a(n) _____ entity.

strong

A(n) _____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

subtype discriminator

A _____ relationship exists when three entities are associated.

ternary

Normalization works through a series of stages called normal forms. For most purposes in business database design, _____ stages are as high as you need to go in the normalization process.

three

At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship.

true

In order to meet performance requirements, portions of the database design may need to be occasionally denormalized.

true

One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their supertype.

true

Since a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF.

true

The entity supertype contains common characteristics, and the entity subtypes each contain their own unique characteristics.

true

A _____ relationship exists when an association is maintained within a single entity.

unary