WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What does modality refer to? How does it appear on ER diagram? -
ANSWER--Refers to the MINIMUM number of times an instance in
one entity can be associated with instance of another entity (minima)
Appears as a 0 or 1 on the relationship line, next to cardinality
Define: Referential Integrity - ANSWER--Requires that ALL foreign
key values must either be fully NULL or match some primary key value
4 Ways Referential Integrity can be violated: - ANSWER--1. Primary
key is updated
2. Foreign key is updated
3. Row containing primary key is DELETED
4. Row containing foreign key is INSERTED
4 Actions to Correct Referential Integrity Violation: - ANSWER--1.
RESTRICT - rejects an insert, update, or delete
2. SET NULL - sets invalid foreign keys to null
3. SET DEFAULT - sets invalid foreign keys to a default primary value
4. CASCADE - propagates primary key changes to foreign keys
,WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What is an important aspect to referential integrity? - ANSWER--
reference to data in one relation is based on values in another relation
What is a broad definition of data? - ANSWER--Raw facts captured on
printed or digital media
What are data? - ANSWER--Facts that are collected and stored in a
database system
What is a determining characteristic of unstructured data? - ANSWER--
It does not follow a data model
What is true about flat files? - ANSWER--- They contain no internal
hierarchical organization
How were data retrieved before database management systems? -
ANSWER--Sequentially from simple files
What is an attribute or group of attributes that uniquely identify a tuple
in a relation? - ANSWER--Primary Key
, WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What is necessary for a primary key in one relation of a database to
match with its corresponding foreign key in another relation of the same
database? - ANSWER--A domain of values
What uniquely identifies each entity in a collection of entities but is not
the primary key? - ANSWER--Alternate Key
What is the term for a set of columns in a table that can uniquely identify
any record in that table without referring to other data? - ANSWER--
Candidate Key
What happens to the original data in database indexing? - ANSWER--It
is copied to the index
Why are indexes created in a physical database design? - ANSWER--To
retrieve data DIRECTLY using a pointer
Why is an index created on a database column? - ANSWER--To
optimize data retrievals
Define: Functional Dependency - ANSWER--Each value of a column
relates to at MOST one value of another column
Dependence of one column on another
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What does modality refer to? How does it appear on ER diagram? -
ANSWER--Refers to the MINIMUM number of times an instance in
one entity can be associated with instance of another entity (minima)
Appears as a 0 or 1 on the relationship line, next to cardinality
Define: Referential Integrity - ANSWER--Requires that ALL foreign
key values must either be fully NULL or match some primary key value
4 Ways Referential Integrity can be violated: - ANSWER--1. Primary
key is updated
2. Foreign key is updated
3. Row containing primary key is DELETED
4. Row containing foreign key is INSERTED
4 Actions to Correct Referential Integrity Violation: - ANSWER--1.
RESTRICT - rejects an insert, update, or delete
2. SET NULL - sets invalid foreign keys to null
3. SET DEFAULT - sets invalid foreign keys to a default primary value
4. CASCADE - propagates primary key changes to foreign keys
,WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What is an important aspect to referential integrity? - ANSWER--
reference to data in one relation is based on values in another relation
What is a broad definition of data? - ANSWER--Raw facts captured on
printed or digital media
What are data? - ANSWER--Facts that are collected and stored in a
database system
What is a determining characteristic of unstructured data? - ANSWER--
It does not follow a data model
What is true about flat files? - ANSWER--- They contain no internal
hierarchical organization
How were data retrieved before database management systems? -
ANSWER--Sequentially from simple files
What is an attribute or group of attributes that uniquely identify a tuple
in a relation? - ANSWER--Primary Key
, WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
OA EXAM 2024-2025 ACTUAL EXAM 2 QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT AND
VERIFIED ANSWERS)|ALREADY GRADED A+
What is necessary for a primary key in one relation of a database to
match with its corresponding foreign key in another relation of the same
database? - ANSWER--A domain of values
What uniquely identifies each entity in a collection of entities but is not
the primary key? - ANSWER--Alternate Key
What is the term for a set of columns in a table that can uniquely identify
any record in that table without referring to other data? - ANSWER--
Candidate Key
What happens to the original data in database indexing? - ANSWER--It
is copied to the index
Why are indexes created in a physical database design? - ANSWER--To
retrieve data DIRECTLY using a pointer
Why is an index created on a database column? - ANSWER--To
optimize data retrievals
Define: Functional Dependency - ANSWER--Each value of a column
relates to at MOST one value of another column
Dependence of one column on another
