Texas Database Administrator Licensing
Exam Practice Test Questions And Correct
Answers (Verified Answers) Plus Rationales
|2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a database index?
A. To enforce referential integrity
B. To store metadata
C. To speed up data retrieval
D. To normalize data
Indexes improve the performance of data retrieval operations by allowing faster
access to rows in a table.
2. Which SQL command is used to remove a table and all its data?
A. DELETE
B. DROP
C. ERASE
D. REMOVE
The DROP command deletes the table structure and its data permanently from
the database.
3. What does ACID stand for in database transactions?
,A. Access, Control, Input, Delete
B. Asynchronous, Commit, Integrity, Durability
C. Atomicity, Consistency, Isolation, Durability
D. Algorithm, Consistency, Isolation, Durability
ACID ensures reliable processing of database transactions.
4. In normalization, what is the purpose of converting to 3NF (Third Normal
Form)?
A. To remove composite keys
B. To eliminate transitive dependencies
C. To ensure atomic values
D. To improve encryption
Third Normal Form removes transitive dependencies to reduce redundancy and
improve integrity.
5. Which type of JOIN returns all rows from both tables, matching where
possible?
A. FULL OUTER JOIN
B. INNER JOIN
C. LEFT JOIN
D. RIGHT JOIN
FULL OUTER JOIN returns all records when there is a match in either left or right
table.
6. What is the default isolation level in most relational databases?
A. Read Uncommitted
B. Repeatable Read
C. Read Committed
D. Serializable
Read Committed is commonly the default because it balances consistency and
performance.
, 7. Which constraint ensures that values in a column are unique?
A. CHECK
B. UNIQUE
C. NOT NULL
D. FOREIGN KEY
The UNIQUE constraint prevents duplicate values in a column.
8. Which data model uses tables, rows, and columns?
A. Hierarchical
B. Object-Oriented
C. Relational
D. NoSQL
Relational databases organize data in tables consisting of rows and columns.
9. What is a foreign key?
A. A unique identifier for a record
B. A key used to link two tables
C. A key that can be null
D. A key that has duplicate values
A foreign key establishes a relationship between columns in different tables.
10. Which command is used to retrieve data from a database?
A. INSERT
B. SELECT
C. CREATE
D. UPDATE
SELECT is used to retrieve data from one or more tables.
11. What is the function of a primary key?
Exam Practice Test Questions And Correct
Answers (Verified Answers) Plus Rationales
|2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a database index?
A. To enforce referential integrity
B. To store metadata
C. To speed up data retrieval
D. To normalize data
Indexes improve the performance of data retrieval operations by allowing faster
access to rows in a table.
2. Which SQL command is used to remove a table and all its data?
A. DELETE
B. DROP
C. ERASE
D. REMOVE
The DROP command deletes the table structure and its data permanently from
the database.
3. What does ACID stand for in database transactions?
,A. Access, Control, Input, Delete
B. Asynchronous, Commit, Integrity, Durability
C. Atomicity, Consistency, Isolation, Durability
D. Algorithm, Consistency, Isolation, Durability
ACID ensures reliable processing of database transactions.
4. In normalization, what is the purpose of converting to 3NF (Third Normal
Form)?
A. To remove composite keys
B. To eliminate transitive dependencies
C. To ensure atomic values
D. To improve encryption
Third Normal Form removes transitive dependencies to reduce redundancy and
improve integrity.
5. Which type of JOIN returns all rows from both tables, matching where
possible?
A. FULL OUTER JOIN
B. INNER JOIN
C. LEFT JOIN
D. RIGHT JOIN
FULL OUTER JOIN returns all records when there is a match in either left or right
table.
6. What is the default isolation level in most relational databases?
A. Read Uncommitted
B. Repeatable Read
C. Read Committed
D. Serializable
Read Committed is commonly the default because it balances consistency and
performance.
, 7. Which constraint ensures that values in a column are unique?
A. CHECK
B. UNIQUE
C. NOT NULL
D. FOREIGN KEY
The UNIQUE constraint prevents duplicate values in a column.
8. Which data model uses tables, rows, and columns?
A. Hierarchical
B. Object-Oriented
C. Relational
D. NoSQL
Relational databases organize data in tables consisting of rows and columns.
9. What is a foreign key?
A. A unique identifier for a record
B. A key used to link two tables
C. A key that can be null
D. A key that has duplicate values
A foreign key establishes a relationship between columns in different tables.
10. Which command is used to retrieve data from a database?
A. INSERT
B. SELECT
C. CREATE
D. UPDATE
SELECT is used to retrieve data from one or more tables.
11. What is the function of a primary key?
