WGU C175 QUESTIONS AND ANSWERS
LATEST UPDATE
Flat Files
a file having no internal hierarchy
Hashed Files
A file that has been encrypted for security purposes.
Heap File
An unsorted set of records.
Information
The transformation of raw data into useful facts.
Punch Card
A card that is perforated and can hold commands or data.
Structured Data
Information with a high degree of organization.
Unstructured Data
Information that does not have structure (such as text)
Binary Relationship
A relationship between two entity types.
Unary Relationship
An associate occurrence of an entity type with other occurrences of the same entity
type.
Cardinality
The maximum number of entities that can be involved in a particular relationship.
E-R Model
*E-R = Entity - Relationship
Diagram of entities together with their attributes and the relationship among them.
Intersection Data
It is data that describes a many-to-many relationship.
Modality
It is a minimum number of entity occurrences that can be involved in a relationship.
One-to-one Binary Relationship
It means that a single occurrence of one entity type can be associated with a single
occurrence of the other entity type and vice versa.
Ternary Relationship
Involves three different entity types.
Unique identifier
It is used to uniquely identify each record in a database table.
Attribute
, A property, characteristic, or fact that we know about an entity.
"A salesperson works in one office."
What is the name of this relationship?
One-to-one binary relationship
"A salesperson sells to many customers."
What is the name of this relationship?
One-to-many binary relationship
"A salesperson is authorized to sell many products, and a product can be sold by
many salespersons."
What is the name of this relationship?
Many-to-many binary relationship
What is the positioning and meaning for Cardinality and Modality on an E-R
model?
Cardinality is the outer symbol; represents the maximum.
Modality is the inner symbol; represents the minimum.
"A salesperson works in a minimum of one and a maximum of one office, and an
office may be occupied by or assigned to a minimum of zero and a maximum of
one salesperson."
"A salesperson may have no customers or many customers."
Describe the ER model for "Each salesperson is authorized to sell to at least one
or many products, and each product can be sold by at least one or many
salespeople."
"One salesperson backs-up another salesperson."
What is the name of this model?
One-to-one unary relationship
"A salesperson manages zero to many other salespersons, and a salesperson is
managed by exactly one other salesperson."
What is the name of this model?
One-to-many unary relationship
"A product can either be part of no other products or be part of several other
products, and a product can either be composed of no other products or be
composed of several other products."
What is the name of this model?
Many-to-many unary relationship
What does 'refer' in Referential Integrity imply?
This revolves around the circumstance of trying to refer to data in one relation in the
database, based on values in another relation.
Define the delete rule RESTRICT.
LATEST UPDATE
Flat Files
a file having no internal hierarchy
Hashed Files
A file that has been encrypted for security purposes.
Heap File
An unsorted set of records.
Information
The transformation of raw data into useful facts.
Punch Card
A card that is perforated and can hold commands or data.
Structured Data
Information with a high degree of organization.
Unstructured Data
Information that does not have structure (such as text)
Binary Relationship
A relationship between two entity types.
Unary Relationship
An associate occurrence of an entity type with other occurrences of the same entity
type.
Cardinality
The maximum number of entities that can be involved in a particular relationship.
E-R Model
*E-R = Entity - Relationship
Diagram of entities together with their attributes and the relationship among them.
Intersection Data
It is data that describes a many-to-many relationship.
Modality
It is a minimum number of entity occurrences that can be involved in a relationship.
One-to-one Binary Relationship
It means that a single occurrence of one entity type can be associated with a single
occurrence of the other entity type and vice versa.
Ternary Relationship
Involves three different entity types.
Unique identifier
It is used to uniquely identify each record in a database table.
Attribute
, A property, characteristic, or fact that we know about an entity.
"A salesperson works in one office."
What is the name of this relationship?
One-to-one binary relationship
"A salesperson sells to many customers."
What is the name of this relationship?
One-to-many binary relationship
"A salesperson is authorized to sell many products, and a product can be sold by
many salespersons."
What is the name of this relationship?
Many-to-many binary relationship
What is the positioning and meaning for Cardinality and Modality on an E-R
model?
Cardinality is the outer symbol; represents the maximum.
Modality is the inner symbol; represents the minimum.
"A salesperson works in a minimum of one and a maximum of one office, and an
office may be occupied by or assigned to a minimum of zero and a maximum of
one salesperson."
"A salesperson may have no customers or many customers."
Describe the ER model for "Each salesperson is authorized to sell to at least one
or many products, and each product can be sold by at least one or many
salespeople."
"One salesperson backs-up another salesperson."
What is the name of this model?
One-to-one unary relationship
"A salesperson manages zero to many other salespersons, and a salesperson is
managed by exactly one other salesperson."
What is the name of this model?
One-to-many unary relationship
"A product can either be part of no other products or be part of several other
products, and a product can either be composed of no other products or be
composed of several other products."
What is the name of this model?
Many-to-many unary relationship
What does 'refer' in Referential Integrity imply?
This revolves around the circumstance of trying to refer to data in one relation in the
database, based on values in another relation.
Define the delete rule RESTRICT.
