Chapter 4: Entity Relationship (ER) Modeling

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

1

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.

1

A weak entity must meet two conditions:

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

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

Cadinality

The ____ notation favors conceptual modeling.

Chen

____ models are used in the conceptual design of databases.

Conceptual

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

Crow's foot

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

Design

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

ERD (Entity Relationship Diagram)

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

ERD (Entity Relationship Diagram)

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

ERD (Entity Relationship Diagram)

The ____ is independent of the database type.

ERM

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

False

True or False: Attributes do not have a domain.

False

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

False

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

False, it only directly applies to Crow's Foot diagrams

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

Mandatory

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

Optional

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

Processing

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

Referential integrity

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

Strong relationship or identifying relationship

True of False: Attributes may share a domain.

True

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

True

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

True

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.

True

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

True

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.

True

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

True

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

True

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

True

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.

True

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.

True

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.

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

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

UML

A ____ relationship exists when two entities are associated.

binary

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

business rules

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

business rules

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

cardinalities

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

cardinalities

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

composite

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

composite

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

composite entity, bridge or associative entity

Derived attributes are sometimes referred to as ____ attributes.

computed

The term ____ is used to describe the relationship classification.

connectivity

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

entity (the "many" side of the relationship)

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

entity occurance

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

existence-dependent

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

existence-dependent

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

existence-independent

In the ERD, ____ are underlined.

identifiers (primary key)

Cardinality (N) means?

indeterminate

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

information generation

An ____ is based on repetition of processes and procedures.

iterative process

Relation models are used in the ____ design of databases.

logical

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

mandatory

A ____ attribute are attributes that can have many values.

multivalued

The word entity and ____ are often used interchangeably.

object

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

optional

Participation in a relationship is either ____ or ____.

optional or mandatory

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

optionality

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

participants

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

participation

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

participation and referential integrity

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

primary, candidate

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

recursive

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

relationship

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

relationship

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

relationship degree

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

required

A ____ attribute is an attribute that cannot be subdivided.

simple

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

single-valued

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.

solid

The ____ notation favors a more implementation-oriented approach.

Crow's foot

True or False: Referential integrity is not bidirectional.

True

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

active or passive

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

derived

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.

design standards

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

domain

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

entity

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

identifier (primary key)

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

optional

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

strength, participation

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

strong

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

strong entity, regular entity

A ____ relationship exists when three entities are associated.

ternary

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

unary

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

weak

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

weak relationship or non-identifying relationship