Chapter 4: Entity Relationship (ER) Modeling

question

The ____ is independent of the database type.
answer

ERM
question

____ models are used in the conceptual design of databases.
answer

Conceptual
question

Relation models are used in the ____ design of databases.
answer

logical
question

The ERM (Entity Relationship Model) forms the bases of an ____.
answer

ERD (Entity Relationship Diagram)
question

The ____ represents the conceptual database as viewed by the end user,
answer

ERD (Entity Relationship Diagram)
question

A ____ depicts the database’s main components: entities, attributes and relationships.
answer

ERD (Entity Relationship Diagram)
question

The word entity and ____ are often used interchangeably.
answer

object
question

The ____ notation favors conceptual modeling.
answer

Chen
question

The ____ notation favors a more implementation-oriented approach.
answer

Crow’s foot
question

The ____ notation can be used for both conceptual and implementation modeling.
answer

UML
question

An ____ in the ERM corresponds to a table-not a row- in the relational environment.
answer

entity
question

The ERM refers to a table row an an ____ or the entity’s name.
answer

entity occurance
question

A ____ attribute is an attribute that must have a value; therefore, it cannot be left empty.
answer

required
question

An ____ attribute is an attribute that does not require a value; therefore, it can be left empty.
answer

optional
question

True or False: Attributes do not have a domain.
answer

False
question

A ____ is a set of possible values given to an attribute.
answer

domain
question

True of False: Attributes may share a domain.
answer

True
question

True or False:The data dictionary may let a newly declared attribute inherit the characteristics of an existing attribute of the same attribute name is used.
answer

True, PROFESSOR and STUDENT entities may each have an attribute named address.
question

An ____ , one or more attributes that uniquely identify each entity instance.
answer

identifier (primary key)
question

In the ERD, ____ are underlined.
answer

identifiers (primary key)
question

A ____ identifier is a primary key composed of more than one attribute.
answer

composite
question

If a ____ key was deleted, the ____ key would become an acceptable composite primary key because the instance would still be uniquely identifiable.
answer

primary, candidate
question

True or False: Attributes are classified as simple or composite?
answer

True
question

A ____ attribute is an attribute that can be further subdivided to yield additional attributes.
answer

composite
question

A ____ attribute is an attribute that cannot be subdivided.
answer

simple
question

A ____ attribute is an attribute that can have only a single value.
answer

single-valued
question

True or False: A single-valued attribute is always a simple attribute.
answer

False
question

A ____ attribute are attributes that can have many values.
answer

multivalued
question

True or False: If possible, it is best to create a new entity set composed of multivalued attribute components rather than to make multivalued attributes into their own attribute.
answer

True
question

A ____ attribute is an attribute whose value is calculated (derived) from other attributes.
answer

derived
question

The ____ notation does not have a method for distinguishing the derived attribute from other attributes.
answer

Crow’s foot
question

Derived attributes are sometimes referred to as ____ attributes.
answer

computed
question

The entities that participate in relationships are also knows as ____.
answer

participants
question

Each relationship name (describes the relationship) is an ____ or ____ verb.
answer

active or passive
question

The term ____ is used to describe the relationship classification.
answer

connectivity
question

____ expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.
answer

Cadinality
question

The DBMS cannot implement ____ at the table level-that capability is provided by the application software or by triggers.
answer

cardinalities
question

Connectivities and cardinalities are established by concise statements known as ____.
answer

business rules
question

An entity is said to be ____ if it can exist in the database only when it is associated with another related entity occurrence.
answer

existence-dependent
question

An entity is ____ if it has a mandatory foreign key-that is, a foreign key attribute that cannot be null.
answer

existence-dependent
question

If an entity can exist apart from all of its related entities, then it is ____.
answer

existence-independent
question

An existence-dependent entity is also referred to as a ____ or ____.
answer

strong entity, regular entity
question

The concept of ____ strength is based on how the primary key of a related entity is defined.
answer

relationship
question

True or False: The DBMS cannot handle the implementation of the cardinalities at the table level?
answer

True
question

Connectivities and ____ are established by concise statements known as business rules?
answer

cardinalities
question

True or False: The relationship strength is part of the original ERM?
answer

False, it only directly applies to Crow’s Foot diagrams
question

It is important to understand ____ strength as it affects database implementation.
answer

relationship
question

A ____ or ____, exists if the primary key of the related entity does not contain a primary key component of the parent entity.
answer

weak relationship or non-identifying relationship
question

A ____ or ____, exists when the primary key of the related entity contains a primary component of the parent entity.
answer

Strong relationship or identifying relationship
question

True of False: The order in which the tables are created and loaded is very important.
answer

True
question

You must load the data of the ____ side first in a 1:M relationship to avoid the possibility o referential integrity errors, regardless of whether the relationships are weak or strong.
answer

1
question

A weak entity must meet two conditions:
answer

1. The entity is existence-dependent: it cannot exist without the entity with which it has a relationship 2. The entity has a primary key that is partially or totally derived from the parent entity in the relationship
question

The database designed usually determines whether an entity can be described as weak based on the ____.
answer

business rules
question

Participation in a relationship is either ____ or ____.
answer

optional or mandatory
question

You must consider the bidirectional nature of the relationship when determining ____.
answer

participation
question

____ participation means that one entity occurrence does not require a corresponding entity occurrence in a particular relationship.
answer

Optional
question

The existence of an ____ entity indicatives that its minimum cardinality is 0.
answer

optional
question

The term ____ is used to label any condition in which one or more optional relationships exist.
answer

optionality
question

The burden of establishing the relationship is always placed on the ____ that contains the foreign key.
answer

entity (the “many” side of the relationship)
question

____ participation means that one entity occurrence requires a corresponding entity occurrence is a particular relationship.
answer

Mandatory
question

If no optionality symbol is depicted with the entity, the entity is assumed to exist in a ____ relationship with the related entity
answer

mandatory
question

The existence of a mandatory relationship indicates that the minimum cardinality is a least ____ for the mandatory entity.
answer

1
question

True or False: Relationship strength and relationship participation mean the same thing.
answer

False
question

A ____ relationship can exist when one entity is optional to another.
answer

strong
question

It is possible for a ____ relationship to be established when one entity is mandatory to another.
answer

weak
question

The relationship ____ depends on how the PK of the related entity is formulated, while the relationship ____ depends on how the business rule is written
answer

strength, participation
question

A ____ indicates the number of entities or participants associated with a relationship.
answer

relationship degree
question

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

unary
question

A ____ relationship exists when two entities are associated.
answer

binary
question

A ____ relationship exists when three entities are associated.
answer

ternary
question

True or False: One common pitfall when working with unary relationships is to confuse participation with referential integrity.
answer

True
question

True or False: Participation is bidirectional and it must be addressed in both directions along the relationship
answer

True
question

True or False: Referential integrity is not bidirectional.
answer

True
question

Both ____ and ____ involve the values used as PKs and FKs to implement the relationship
answer

participation and referential integrity
question

____ requires that the values in the FK correspond to values in the PK.
answer

Referential integrity
question

A ____ relationship is one in which a relationship can exist between occurrences of the same entity set.
answer

recursive
question

A ____ entity, is a 1:M relationship with the parent entities and is composed of the PK attributes of each parent entity.
answer

composite entity, bridge or associative entity
question

When using the Crow’s foot notation, the associative entity is identified as a strong (identifying) relationship, as indicated by the _____ relationship line between the parents and associative entity.
answer

solid
question

An ____ is based on repetition of processes and procedures.
answer

iterative process
question

True or False: The ERD process is repeated until the end users and designers agree that the ERD is a fair representation of the organization’s activities and functions.
answer

True
question

Cardinality (N) means?
answer

indeterminate
question

True or False: Do not use 1:1 relationships lightly and make sure that the relationship within the database design is defensible.
answer

True
question

True or False: Database designers must often make design compromises that are triggered by conflicting goals, such as adherence to design standards (design elegance), processing speed and information requirements.
answer

True
question

____ standards guide you in developing logical structures that minimize data redundancies, thereby minimizing the likelihood of destructive data anomalies.
answer

Design
question

Without ____, it is nearly impossible to formulate a proper design process, to evaluate an existing design, or to trace the likely logical impact of changes in design.
answer

design standards
question

____ speeds means minimal access time, which may be achieved by minimizing the number and complexity of logically desired relationships.
answer

Processing
question

A database may have to sacrifice some of its “clean design structures and high transaction speed to ensure maximum ____.
answer

information generation
question

True or False:While focusing on entities, attributes, relationships and constraint, the designer should begin thinking about end-user requirements such as performance, security, shared access and data integrity.
answer

True

Get instant access to
all materials

Become a Member