WGU D330 – Data Systems
Administration Final Prep Exam (Latest
Update 2026/2027) Questions and
Verified Answers | 100% Correct |
Grade A.
1. A database administrator needs to ensure that a database remains
available even if the primary database server fails. Which solution
provides the best availability improvement?
A. Database normalization
B. Regular database backups
C. Database replication
D. Data compression
Answer: C. Database replication
Database replication creates copies of a database across multiple
servers. If the primary server fails, another replicated instance can
continue serving requests, improving availability and fault tolerance.
Backups protect against data loss but do not provide immediate
availability.
, 2. Which database component is responsible for storing metadata
about database objects such as tables, indexes, and users?
A. Query optimizer
B. Data dictionary
C. Transaction log
D. Buffer cache
Answer: B. Data dictionary
The data dictionary stores information about the structure and
organization of a database, including schemas, tables, columns,
constraints, and user permissions. It is essential for database
management and administration.
3. A database administrator wants to prevent unauthorized users
from accessing sensitive customer records. Which security
principle should be applied?
A. Least privilege
B. Data redundancy
C. Load balancing
D. Index optimization
Answer: A. Least privilege
The principle of least privilege ensures that users receive only the
permissions necessary to perform their job functions. This reduces the
risk of unauthorized access or accidental data modification.
, 4. Which SQL command is used to remove an entire table and its
associated data from a database?
A. DELETE
B. REMOVE
C. DROP
D. TRUNCATE
Answer: C. DROP
The DROP command permanently removes a database object, such as a
table, along with its structure and data. DELETE removes rows, while
TRUNCATE removes all rows but leaves the table structure intact.
5. A database administrator notices slow query performance caused
by frequent table scans. Which solution would most likely improve
performance?
A. Adding indexes
B. Increasing normalization
C. Removing constraints
D. Disabling backups
Answer: A. Adding indexes
Indexes allow the database engine to locate data more efficiently
without scanning every row in a table. Proper indexing improves query
performance, especially for frequently searched columns.
6. Which type of database backup contains all changes made since
the last full backup?
, A. Differential backup
B. Incremental backup
C. Snapshot backup
D. Transaction backup
Answer: A. Differential backup
A differential backup stores all changes made since the last full backup.
Unlike incremental backups, each differential backup grows larger until
another full backup is performed.
7. Which database language is primarily used for defining database
structures?
A. DML
B. DDL
C. DCL
D. TCL
Answer: B. DDL
Data Definition Language (DDL) includes commands such as CREATE,
ALTER, and DROP that define and modify database structures such as
tables, schemas, and indexes.
8. A database administrator executes a transaction that updates
multiple records. Which feature ensures that either all changes
occur or none occur?
A. Indexing
B. Atomicity
Administration Final Prep Exam (Latest
Update 2026/2027) Questions and
Verified Answers | 100% Correct |
Grade A.
1. A database administrator needs to ensure that a database remains
available even if the primary database server fails. Which solution
provides the best availability improvement?
A. Database normalization
B. Regular database backups
C. Database replication
D. Data compression
Answer: C. Database replication
Database replication creates copies of a database across multiple
servers. If the primary server fails, another replicated instance can
continue serving requests, improving availability and fault tolerance.
Backups protect against data loss but do not provide immediate
availability.
, 2. Which database component is responsible for storing metadata
about database objects such as tables, indexes, and users?
A. Query optimizer
B. Data dictionary
C. Transaction log
D. Buffer cache
Answer: B. Data dictionary
The data dictionary stores information about the structure and
organization of a database, including schemas, tables, columns,
constraints, and user permissions. It is essential for database
management and administration.
3. A database administrator wants to prevent unauthorized users
from accessing sensitive customer records. Which security
principle should be applied?
A. Least privilege
B. Data redundancy
C. Load balancing
D. Index optimization
Answer: A. Least privilege
The principle of least privilege ensures that users receive only the
permissions necessary to perform their job functions. This reduces the
risk of unauthorized access or accidental data modification.
, 4. Which SQL command is used to remove an entire table and its
associated data from a database?
A. DELETE
B. REMOVE
C. DROP
D. TRUNCATE
Answer: C. DROP
The DROP command permanently removes a database object, such as a
table, along with its structure and data. DELETE removes rows, while
TRUNCATE removes all rows but leaves the table structure intact.
5. A database administrator notices slow query performance caused
by frequent table scans. Which solution would most likely improve
performance?
A. Adding indexes
B. Increasing normalization
C. Removing constraints
D. Disabling backups
Answer: A. Adding indexes
Indexes allow the database engine to locate data more efficiently
without scanning every row in a table. Proper indexing improves query
performance, especially for frequently searched columns.
6. Which type of database backup contains all changes made since
the last full backup?
, A. Differential backup
B. Incremental backup
C. Snapshot backup
D. Transaction backup
Answer: A. Differential backup
A differential backup stores all changes made since the last full backup.
Unlike incremental backups, each differential backup grows larger until
another full backup is performed.
7. Which database language is primarily used for defining database
structures?
A. DML
B. DDL
C. DCL
D. TCL
Answer: B. DDL
Data Definition Language (DDL) includes commands such as CREATE,
ALTER, and DROP that define and modify database structures such as
tables, schemas, and indexes.
8. A database administrator executes a transaction that updates
multiple records. Which feature ensures that either all changes
occur or none occur?
A. Indexing
B. Atomicity
