WGU D330 Objective Assessment 2 - Complete Practice Exam: Multiple-Choice Questions with Rationales for Oracle Database Administration (2026)

WGU D330 Objective Assessment 2 -
Complete Practice Exam: Multiple-
Choice Questions with Rationales for
Oracle Database Administration
(2026)


Oracle Architecture & SGA (Questions 1-30)

Q1: Which two SGA structures are required in every Oracle instance?
(Choose two.)

 A. Large pool
 B. Shared pool
 C. Database buffer cache
 D. Java pool

Answer: B and C
Rationale: The Shared Pool and Database Buffer Cache are mandatory
components of the System Global Area (SGA) in every Oracle instance. The
Shared Pool caches SQL statements and data dictionary information, while
the Database Buffer Cache stores data blocks read from disk. The Large
Pool and Java Pool are optional and configured only when specific features
are needed .

,Q2: Which statement best describes the difference between an Oracle
instance and an Oracle database?

 A. An instance consists of memory structures and processes, whereas
a database is composed of physical files.
 B. An instance is used only during database creation; after that, the
database is all that is needed.
 C. An instance is started whenever demands are high, but the
database is used continuously.
 D. An instance is configured using a pfile, whereas a database is
configured using an spfile.

Answer: A
Rationale: The Oracle instance is the combination of memory structures
(SGA and PGA) and background processes that manage the database. The
database itself consists of the physical data files, control files, and redo log
files stored on disk .

Q3: The Database Buffer Cache in the SGA stores:

 A. SQL statements
 B. Data blocks read from disk
 C. Redo log entries
 D. Control file information

Answer: B
Rationale: The Database Buffer Cache stores copies of data blocks read
from data files. This reduces physical I/O by caching frequently accessed
data in memory .

Q4: The Shared Pool in the SGA caches:

 A. Data blocks only

,  B. SQL statements and data dictionary information
 C. Redo log entries
 D. Java objects only

Answer: B
Rationale: The Shared Pool caches parsed SQL statements, PL/SQL code,
and data dictionary information to improve performance by reducing the
need for repeated parsing and dictionary lookups .

Q5: The Large Pool is used for:

 A. Storing data blocks
 B. RMAN backups and shared server operations
 C. Java stored procedures
 D. Caching SQL statements

Answer: B
Rationale: The Large Pool is an optional SGA component used for RMAN
backup and recovery operations, parallel query, and shared server (MTS)
operations .

Q6: Which of the following can be configured to improve performance
for Oracle databases?

 A. SGA_TARGET
 B. PGA_AGGREGATE_TARGET
 C. WORKAREA_SIZE_POLICY
 D. All of the above

Answer: D
Rationale: SGA_TARGET controls the total size of the SGA;
PGA_AGGREGATE_TARGET controls the total size of the PGA; and

, WORKAREA_SIZE_POLICY (when set to AUTO) allows Oracle to
automatically size work areas based on PGA memory usage .

Q7: Which background process writes dirty buffers from the Database
Buffer Cache to data files?

 A. Log Writer (LGWR)
 B. Database Writer (DBWn)
 C. System Monitor (SMON)
 D. Process Monitor (PMON)

Answer: B
Rationale: Database Writer (DBWn) is responsible for writing dirty buffers
(modified data blocks) from the Database Buffer Cache in the SGA to the
data files on disk .

Q8: Which background process writes redo log entries from the redo
log buffer to the online redo log files?

 A. Log Writer (LGWR)
 B. Database Writer (DBWn)
 C. System Monitor (SMON)
 D. Process Monitor (PMON)

Answer: A
Rationale: Log Writer (LGWR) writes redo log entries from the redo log
buffer in the SGA to the online redo log files. This ensures that transaction
changes are recorded for recovery purposes .

Q9: Which background process performs instance recovery at startup?

 A. Log Writer (LGWR)
 B. Database Writer (DBWn)
 C. System Monitor (SMON)