WGU C175 Data Management Foundations – Objective Assessment Study Guide | Latest Update 2026/2027 | Practice Questions And Answers | Exam Review

1 | WGU




WGU C175 Data Management Foundations –
Objective Assessment Study Guide | Latest
Update 2026/2027 | Practice Questions And
Answers | Exam Review.



Table of Contents

1. Introduction to Information and Data
2. The Relational Model of Data
3. Fundamentals of SQL
4. Data Modeling
5. Normalization
6. Business Intelligence

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Question 1: A university maintains separate Excel spreadsheets for student records
in each academic department. When a student changes their major, staff must
manually update the spreadsheet in the old department and create a new entry in
the new department, often resulting in conflicting phone numbers and addresses
across files. Which database characteristic, if implemented, would most directly
eliminate this specific problem?

A) Data independence
B) Data redundancy control
C) Data integrity enforcement
D) Data security

Correct Answer: B) Data redundancy control
Data redundancy control eliminates duplicate storage of the same data across
multiple files by maintaining a single shared repository. In this scenario, a centralized
database would store each student's contact information once, eliminating the need
for manual updates across departmental spreadsheets and preventing conflicting
values. Data independence concerns schema changes not affecting applications,
while data integrity enforces rules but does not inherently prevent redundant storage.

Question 2: A retail corporation uses a database system where the marketing
department sees customer names and purchase histories without viewing credit card
numbers, while the accounting department sees transaction amounts and payment
methods without viewing customer names. The database administrator sees the
complete raw storage structure including file locations and index pointers. Which
three-schema architecture levels are respectively represented by the marketing view,
accounting view, and DBA view?

A) External, External, Internal
B) Conceptual, External, Internal
C) External, Conceptual, Internal
D) External, External, Conceptual

Correct Answer: A) External, External, Internal
The marketing and accounting views are both external schemas (user-specific views
of data), while the DBA's view of physical storage structures represents the internal

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schema. The conceptual schema would show the complete logical structure without
physical details. Therefore, the correct mapping is External, External, Internal.

Question 3: A database administrator modifies the physical storage of a table from
row-based to columnar format to improve analytical query performance. No
application code changes are required, and all SQL queries continue to execute
identically. This scenario best demonstrates which type of data independence?

A) Logical data independence
B) Physical data independence
C) Schema mapping independence
D) Application independence

Correct Answer: B) Physical data independence
Physical data independence ensures that changes to the internal or physical level
(storage structures, indexing, file organization) do not affect the conceptual or
external levels. Changing from row-based to columnar storage is a physical-level
modification. Logical data independence would involve conceptual schema changes
not affecting external views.

Question 4: Which component of the DBMS is directly responsible for parsing a SQL
query, checking syntax against the data dictionary, and generating an optimized
execution plan before the query is executed?

A) Storage manager
B) Transaction manager
C) Query processor
D) Data catalog

Correct Answer: C) Query processor
The query processor (also called query compiler or optimizer) parses SQL
statements, validates them against the data dictionary, performs semantic analysis,
and generates an optimized execution plan. The storage manager handles data
access, the transaction manager ensures ACID properties, and the data catalog
stores metadata.

Question 5: A hospital's database contains a table PATIENT with columns PatientID,
Name, and BloodType. Another table ALLERGY contains AllergyID, PatientID, and

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AllergenName. A query must retrieve all patients who have at least one allergy
recorded. Which SQL construct is most appropriate?

A) INNER JOIN
B) LEFT JOIN
C) EXISTS subquery
D) CROSS JOIN

Correct Answer: C) EXISTS subquery
EXISTS is used to check whether a subquery returns any rows. In this case,
selecting patients where an EXISTS subquery finds matching Allergy records
retrieves patients with at least one allergy. An INNER JOIN would also work but
could return duplicate patient rows if multiple allergies exist. EXISTS avoids
duplicates and is often more efficient.

Question 6: A database designer is creating an entity-relationship diagram for a
library system. A book can have multiple authors, and an author can write multiple
books. What type of relationship exists between BOOK and AUTHOR?

A) One-to-One (1:1)
B) One-to-Many (1:M)
C) Many-to-Many (M:N)
D) Unary

Correct Answer: C) Many-to-Many (M:N)
A many-to-many relationship exists when multiple instances of one entity relate to
multiple instances of another. In relational design, this is resolved with an associative
table (e.g., BOOK_AUTHOR) containing foreign keys to both BOOK and AUTHOR.

Question 7: A table is in first normal form (1NF) but contains a composite primary key
(OrderID, ProductID). A non-key attribute ProductName depends only on ProductID.
Which normalization form is violated?

A) 1NF
B) 2NF
C) 3NF
D) BCNF