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Test Bank: WGU D426 Data Management Foundations Exam 2025
– Versions 1, 2 & 3 | 200 Expert-Verified Questions with Correct
Answers & Rationales | Latest Release
Question 1
What is a broad definition of data?
A. Processed information stored in a database
B. Raw facts captured on printed or digital media
C. Structured reports generated from queries
D. Analyzed trends from a data warehouse
Correct Answer: B. Raw facts captured on printed or digital media
Rationale: Data are raw, unprocessed facts collected and stored, as defined in WGU D426
course materials, aligning with foundational data management concepts.
Question 2
What characterizes unstructured data?
A. Follows a strict data model
B. Lacks internal hierarchical organization
C. Stored in relational tables
D. Optimized for analytical queries
Correct Answer: B. Lacks internal hierarchical organization
Rationale: Unstructured data does not follow a predefined model, unlike structured data in
relational databases, per WGU D426 standards.
Question 3
Which technology lacks internal hierarchy?
A. Relational databases
B. Flat files
C. Data warehouses
D. NoSQL databases
Correct Answer: B. Flat files
Rationale: Flat files store data sequentially without hierarchical structure, a key concept in
WGU D426 for understanding data storage.
Question 4
How were data retrieved before database management systems?
A. Through SQL queries
B. Sequentially from simple files
C. Via cloud-based APIs
D. Using NoSQL commands
Correct Answer: B. Sequentially from simple files
Rationale: Pre-DBMS, data retrieval relied on sequential file access, a historical context covered
in WGU D426.
, 2
Question 5
What are two benefits of a database management system (DBMS)?
A. Enables data sharing and permits vast storage
B. Eliminates all data redundancy and errors
C. Restricts access and reduces storage capacity
D. Supports only unstructured data storage
Correct Answer: A. Enables data sharing and permits vast storage
Rationale: DBMS increases effectiveness by enabling data sharing and handling large volumes,
per WGU D426 objectives.
Question 6
What is the uniquely identifiable element in an entity-relationship diagram?
A. Attribute
B. Entity
C. Relationship
D. Cardinality
Correct Answer: B. Entity
Rationale: Entities represent uniquely identifiable objects in an ER diagram, a core concept in
WGU D426 for database design.
Question 7
What does modality refer to in an ER diagram?
A. Maximum relationships between entities
B. Minimum instances of entity association
C. Data type of attributes
D. Primary key constraints
Correct Answer: B. Minimum instances of entity association
Rationale: Modality indicates the minimum number of associations (0 or 1) between entities, as
taught in WGU D426.
Question 8
How does modality appear on an ER diagram?
A. As a crow’s foot notation
B. As a 0 or 1 on the relationship line
C. As a primary key symbol
D. As a dashed attribute line
Correct Answer: B. As a 0 or 1 on the relationship line
Rationale: Modality is denoted by 0 or 1 next to cardinality on ER diagram relationship lines,
per WGU D426.
Question 9
What is referential integrity?
A. Ensures all data is unique
B. Requires foreign keys to be null or match primary keys
C. Prevents duplicate rows in a table
D. Limits data types in columns
, 3
Correct Answer: B. Requires foreign keys to be null or match primary keys
Rationale: Referential integrity ensures foreign key values align with primary keys or are null, a
key WGU D426 concept.
Question 10
Which action violates referential integrity?
A. Updating a primary key
B. Inserting a null primary key
C. Deleting a foreign key row
D. Adding a unique constraint
Correct Answer: A. Updating a primary key
Rationale: Updating a primary key can break foreign key relationships, violating referential
integrity, per WGU D426.
Question 11
Which action corrects a referential integrity violation?
A. Ignore the violation
B. Cascade primary key changes to foreign keys
C. Duplicate the primary key
D. Remove all constraints
Correct Answer: B. Cascade primary key changes to foreign keys
Rationale: CASCADE propagates primary key changes to maintain integrity, as covered in
WGU D426.
Question 12
What is a key aspect of referential integrity?
A. Data is stored in flat files
B. References are based on values in another relation
C. All attributes are unique
D. Tables are unlinked
Correct Answer: B. References are based on values in another relation
Rationale: Referential integrity relies on foreign keys referencing primary keys in related tables,
per WGU D426.
Question 13
What happens during the extraction step of ETL?
A. Data is loaded into a warehouse
B. Data is put into a uniform structure
C. Data is extracted to a staging area
D. Errors are eliminated from data
Correct Answer: C. Data is extracted to a staging area
Rationale: Extraction involves pulling data into a staging area for processing, a WGU D426
ETL process concept.
Question 14
What occurs during the cleanse step of ETL?
, 4
A. Data is structured for analysis
B. Errors are eliminated, and standard abbreviations applied
C. Data is loaded into the warehouse
D. Data is aggregated for reporting
Correct Answer: B. Errors are eliminated, and standard abbreviations applied
Rationale: Cleansing removes errors and standardizes data, per WGU D426 ETL process
objectives.
Question 15
What is the purpose of the integrate step in ETL?
A. Load data into the final database
B. Convert data to a uniform structure
C. Delete redundant records
D. Optimize data for queries
Correct Answer: B. Convert data to a uniform structure
Rationale: Integration ensures data consistency across sources, a key WGU D426 ETL step.
Question 16
What happens during the restructure step of ETL?
A. Data is extracted from sources
B. Data is structured for optimal analysis
C. Data is cleansed of errors
D. Data is loaded into flat files
Correct Answer: B. Data is structured for optimal analysis
Rationale: Restructuring organizes data for analytical efficiency, per WGU D426 ETL
objectives.
Question 17
What is a focus of the load step in ETL?
A. Monitor refreshing volume and frequency
B. Eliminate duplicate records
C. Standardize data formats
D. Extract data from sources
Correct Answer: A. Monitor refreshing volume and frequency
Rationale: The load step involves managing data refresh processes, per WGU D426.
Question 18
During which ETL step is raw data aggregated?
A. Extraction
B. Transformation
C. Loading
D. Integration
Correct Answer: B. Transformation
Rationale: Aggregation occurs during transformation steps like cleansing or restructuring, per
WGU D426.
Test Bank: WGU D426 Data Management Foundations Exam 2025
– Versions 1, 2 & 3 | 200 Expert-Verified Questions with Correct
Answers & Rationales | Latest Release
Question 1
What is a broad definition of data?
A. Processed information stored in a database
B. Raw facts captured on printed or digital media
C. Structured reports generated from queries
D. Analyzed trends from a data warehouse
Correct Answer: B. Raw facts captured on printed or digital media
Rationale: Data are raw, unprocessed facts collected and stored, as defined in WGU D426
course materials, aligning with foundational data management concepts.
Question 2
What characterizes unstructured data?
A. Follows a strict data model
B. Lacks internal hierarchical organization
C. Stored in relational tables
D. Optimized for analytical queries
Correct Answer: B. Lacks internal hierarchical organization
Rationale: Unstructured data does not follow a predefined model, unlike structured data in
relational databases, per WGU D426 standards.
Question 3
Which technology lacks internal hierarchy?
A. Relational databases
B. Flat files
C. Data warehouses
D. NoSQL databases
Correct Answer: B. Flat files
Rationale: Flat files store data sequentially without hierarchical structure, a key concept in
WGU D426 for understanding data storage.
Question 4
How were data retrieved before database management systems?
A. Through SQL queries
B. Sequentially from simple files
C. Via cloud-based APIs
D. Using NoSQL commands
Correct Answer: B. Sequentially from simple files
Rationale: Pre-DBMS, data retrieval relied on sequential file access, a historical context covered
in WGU D426.
, 2
Question 5
What are two benefits of a database management system (DBMS)?
A. Enables data sharing and permits vast storage
B. Eliminates all data redundancy and errors
C. Restricts access and reduces storage capacity
D. Supports only unstructured data storage
Correct Answer: A. Enables data sharing and permits vast storage
Rationale: DBMS increases effectiveness by enabling data sharing and handling large volumes,
per WGU D426 objectives.
Question 6
What is the uniquely identifiable element in an entity-relationship diagram?
A. Attribute
B. Entity
C. Relationship
D. Cardinality
Correct Answer: B. Entity
Rationale: Entities represent uniquely identifiable objects in an ER diagram, a core concept in
WGU D426 for database design.
Question 7
What does modality refer to in an ER diagram?
A. Maximum relationships between entities
B. Minimum instances of entity association
C. Data type of attributes
D. Primary key constraints
Correct Answer: B. Minimum instances of entity association
Rationale: Modality indicates the minimum number of associations (0 or 1) between entities, as
taught in WGU D426.
Question 8
How does modality appear on an ER diagram?
A. As a crow’s foot notation
B. As a 0 or 1 on the relationship line
C. As a primary key symbol
D. As a dashed attribute line
Correct Answer: B. As a 0 or 1 on the relationship line
Rationale: Modality is denoted by 0 or 1 next to cardinality on ER diagram relationship lines,
per WGU D426.
Question 9
What is referential integrity?
A. Ensures all data is unique
B. Requires foreign keys to be null or match primary keys
C. Prevents duplicate rows in a table
D. Limits data types in columns
, 3
Correct Answer: B. Requires foreign keys to be null or match primary keys
Rationale: Referential integrity ensures foreign key values align with primary keys or are null, a
key WGU D426 concept.
Question 10
Which action violates referential integrity?
A. Updating a primary key
B. Inserting a null primary key
C. Deleting a foreign key row
D. Adding a unique constraint
Correct Answer: A. Updating a primary key
Rationale: Updating a primary key can break foreign key relationships, violating referential
integrity, per WGU D426.
Question 11
Which action corrects a referential integrity violation?
A. Ignore the violation
B. Cascade primary key changes to foreign keys
C. Duplicate the primary key
D. Remove all constraints
Correct Answer: B. Cascade primary key changes to foreign keys
Rationale: CASCADE propagates primary key changes to maintain integrity, as covered in
WGU D426.
Question 12
What is a key aspect of referential integrity?
A. Data is stored in flat files
B. References are based on values in another relation
C. All attributes are unique
D. Tables are unlinked
Correct Answer: B. References are based on values in another relation
Rationale: Referential integrity relies on foreign keys referencing primary keys in related tables,
per WGU D426.
Question 13
What happens during the extraction step of ETL?
A. Data is loaded into a warehouse
B. Data is put into a uniform structure
C. Data is extracted to a staging area
D. Errors are eliminated from data
Correct Answer: C. Data is extracted to a staging area
Rationale: Extraction involves pulling data into a staging area for processing, a WGU D426
ETL process concept.
Question 14
What occurs during the cleanse step of ETL?
, 4
A. Data is structured for analysis
B. Errors are eliminated, and standard abbreviations applied
C. Data is loaded into the warehouse
D. Data is aggregated for reporting
Correct Answer: B. Errors are eliminated, and standard abbreviations applied
Rationale: Cleansing removes errors and standardizes data, per WGU D426 ETL process
objectives.
Question 15
What is the purpose of the integrate step in ETL?
A. Load data into the final database
B. Convert data to a uniform structure
C. Delete redundant records
D. Optimize data for queries
Correct Answer: B. Convert data to a uniform structure
Rationale: Integration ensures data consistency across sources, a key WGU D426 ETL step.
Question 16
What happens during the restructure step of ETL?
A. Data is extracted from sources
B. Data is structured for optimal analysis
C. Data is cleansed of errors
D. Data is loaded into flat files
Correct Answer: B. Data is structured for optimal analysis
Rationale: Restructuring organizes data for analytical efficiency, per WGU D426 ETL
objectives.
Question 17
What is a focus of the load step in ETL?
A. Monitor refreshing volume and frequency
B. Eliminate duplicate records
C. Standardize data formats
D. Extract data from sources
Correct Answer: A. Monitor refreshing volume and frequency
Rationale: The load step involves managing data refresh processes, per WGU D426.
Question 18
During which ETL step is raw data aggregated?
A. Extraction
B. Transformation
C. Loading
D. Integration
Correct Answer: B. Transformation
Rationale: Aggregation occurs during transformation steps like cleansing or restructuring, per
WGU D426.
