ORACLE DATABASE ADMINISTRATOR CERTIFICATION –QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF.
Core Domains:
- Database Architecture and Structures
- Installation, Configuration, and Patching
- Storage and Tablespace Management
- User Security, Privileges, and Auditing
- Backup and Recovery Concepts (RMAN)
- Performance Monitoring and Tuning
- High Availability and Data Guard
- Backup and Recovery Operational Scenarios
- Fleet Management and Cloud Integration
- Database Upgrades and Migrations*
Introduction
This comprehensive assessment is engineered to evaluate the core competencies required of a professional Oracle Database Administrator. The exam vali
SECTION ONE: QUESTIONS 1–100
Question 1
An administrator needs to ensure that an Oracle database instance automatically allocates more space to a tablespace when data volume increases, without
manual intervention. Which feature directly supports this requirement?
A. Setting AUTOEXTEND ON on the underlying data files
B. Configuring an Oracle Automatic Storage Management (ASM) disk group with high redundancy
C. Enabling the Resumable Space Allocation feature for all sessions
D. Implementing a database trigger that monitors the DBA_FREE_SPACE view
🟢 Correct answer A. Option
🔴 RATIONALE: Enabling AUTOEXTEND ON on a data file allows the Oracle database to automatically grow the physical file size up to a specified maximum
limit when the existing space in the tablespace is completely utilized. While ASM manages underlying disk striping and mirroring, it does not dynamically
expand a specific data file unless autoextend is configured. Resumable space allocation pauses operations rather than preventing the space error
automatically, and database triggers introduce unnecessary overhead and complexity compared to native data file attributes.
Question 2
,During a critical performance audit, you notice frequent waits on the 'buffer busy waits' event for a specific block in a highly transactional table. The block is
identified as a data block. Which action is the most effective architectural solution to mitigate this contention?
A. Increase the DB_CACHE_SIZE initialization parameter
B. Rebuild the table using Automatic Segment Space Management (ASSM) and increase PCTFREE
C. Switch the database from ARCHIVELOG to NOARCHIVELOG mode
D. Move the tablespace to a disk group with lower latency spindles
🟢 Correct answer B. Option
🔴 RATIONALE: 'Buffer busy waits' on data blocks occur when multiple sessions attempt to access or modify the same data block simultaneously. Using
Automatic Segment Space Management (ASSM) inherently manages free space inside segments using bitmaps rather than free lists, reducing block
contention. Increasing PCTFREE ensures that fewer rows are packed into a single block, distributing concurrent insert and update operations across multiple
blocks and directly lowering concurrent block-level locking conflicts. Increasing cache size or moving disks does not resolve logical block concurrency issues.
Question 3
To comply with internal data privacy regulations, a database administrator must track all changes made to financial records in the database, capturing the
database user, the OS user, the terminal, and the exact SQL statement executed. Which Oracle feature satisfies this regulatory requirement with minimal
performance overhead?
A. Fine-Grained Auditing (FGA)
B. Standard Database Auditing with AUDIT_TRAIL=DB
C. Creating a database AFTER ALTER trigger on the schema
D. Implementing Oracle LogMiner on redolog archives
🟢 Correct answer A. Option
🔴 RATIONALE: Fine-Grained Auditing (FGA) allows administrators to audit specific data access and modifications based on policies attached to tables or
views. FGA automatically captures the exact SQL statement text, bind variables, database user, operating system user, and terminal information, writing this
data directly to the audit trail. FGA is highly optimized for performance compared to row-level triggers, and standard database auditing does not natively
capture the full SQL statement text for standard DML operations without comprehensive, high-overhead configurations.
Question 4
A junior administrator accidently drops an internal lookup table 'REG_CODES' from a production pluggable database (PDB) at 14:00 hours. It is now 14:30
hours. The database is in ARCHIVELOG mode, and FLASHBACK MARKET is disabled. What is the most efficient way to recover this table without impacting
the rest of the database?
A. Perform an RMAN point-in-time recovery of the entire container database (CDB)
B. Execute an RMAN table recovery command specifying the dropped table and the target time
C. Use Flashback Database to revert the entire PDB to 13:59 hours
D. Restore the tablespace containing the table to a separate auxiliary instance and export the data
🟢 Correct answer B. Option
🔴 RATIONALE: In modern Oracle versions, RMAN provides the ability to recover specific tables or table partitions to a past point in time directly from
backups. RMAN automates the process by creating an auxiliary instance, restoring the required tablespace, recovering it to the designated point in time, and
then exporting/importing the table back to the source database. This avoids taking the entire PDB or CDB offline, making it far more efficient than a full point-
in-time database recovery or manual auxiliary instance setups. Flashback Database cannot be used because it is disabled.
Question 5
An Oracle Database instance fails suddenly due to a power outage on the hosting server. Upon restarting the server and instance, which background process
is primarily responsible for rolling back uncommitted transactions and ensuring data consistency?
, A. PMON
B. SMON
C. DBWn
D. LGWR
🟢 Correct answer B. Option
🔴 RATIONALE: The System Monitor (SMON) background process performs instance recovery at database startup. This includes rolling forward changes in
the online redo logs that were not yet written to the data files (redo phase) and subsequently rolling back transactions that were active but uncommitted at the
time of the crash (undo phase). PMON handles process cleanup for failed user sessions. DBWn writes dirty blocks from the buffer cache to disk, and LGWR
writes redo entries to disk.
Question 6
You need to configure network connectivity for an Oracle database so that client applications can connect via a connection pool. Which file on the database
server must be configured to define the listener port, protocol, and database service registrations?
A. tnsnames.ora
B. sqlnet.ora
C. listener.ora
D. hosts
🟢 Correct answer C. Option
🔴 RATIONALE: The listener.ora file is the configuration file for the Oracle Net Listener process residing on the database server. It defines the protocol
addresses, ports, and specific database service names that the listener listens on to receive incoming client connection requests. The tnsnames.ora file is
primarily configured on the client side to map connection strings to listener addresses, and sqlnet.ora configures general network software parameters.
Question 7
A business application requires a high-performance database setup where read queries never block write operations, and write operations never block read
operations. How does the Oracle database engine natively handle this concurrency requirement?
A. By utilizing table-level locks for all DML statements
B. Through multi-version read consistency using Undo data
C. By enforcing serializable isolation levels by default for all sessions
D. Through the aggressive use of latching mechanisms in the shared pool
🟢 Correct answer B. Option
🔴 RATIONALE: Oracle Database uses Undo data to implement multi-version read consistency. When a transaction modifies a block, the old data values are
written to the Undo segments. When another session executes a read query against that same data concurrently, Oracle reads the committed data from the
Undo segments to present a point-in-time consistent view of the data. This completely prevents readers from blocking writers and writers from blocking
readers.
Question 8
An organization must ensure that all sensitive columns, such as credit card numbers, are encrypted at rest on the storage subsystem to prevent data exposure
via stolen backup tapes or compromised disk drives. Which Oracle feature should be implemented?
A. Virtual Private Database (VPD)
B. Transparent Data Encryption (TDE)
C. Oracle Data Masking and Subsetting
D. Data Redaction
🟢 Correct answer B. Option
Q&A | INSTANT DOWNLOAD PDF.
Core Domains:
- Database Architecture and Structures
- Installation, Configuration, and Patching
- Storage and Tablespace Management
- User Security, Privileges, and Auditing
- Backup and Recovery Concepts (RMAN)
- Performance Monitoring and Tuning
- High Availability and Data Guard
- Backup and Recovery Operational Scenarios
- Fleet Management and Cloud Integration
- Database Upgrades and Migrations*
Introduction
This comprehensive assessment is engineered to evaluate the core competencies required of a professional Oracle Database Administrator. The exam vali
SECTION ONE: QUESTIONS 1–100
Question 1
An administrator needs to ensure that an Oracle database instance automatically allocates more space to a tablespace when data volume increases, without
manual intervention. Which feature directly supports this requirement?
A. Setting AUTOEXTEND ON on the underlying data files
B. Configuring an Oracle Automatic Storage Management (ASM) disk group with high redundancy
C. Enabling the Resumable Space Allocation feature for all sessions
D. Implementing a database trigger that monitors the DBA_FREE_SPACE view
🟢 Correct answer A. Option
🔴 RATIONALE: Enabling AUTOEXTEND ON on a data file allows the Oracle database to automatically grow the physical file size up to a specified maximum
limit when the existing space in the tablespace is completely utilized. While ASM manages underlying disk striping and mirroring, it does not dynamically
expand a specific data file unless autoextend is configured. Resumable space allocation pauses operations rather than preventing the space error
automatically, and database triggers introduce unnecessary overhead and complexity compared to native data file attributes.
Question 2
,During a critical performance audit, you notice frequent waits on the 'buffer busy waits' event for a specific block in a highly transactional table. The block is
identified as a data block. Which action is the most effective architectural solution to mitigate this contention?
A. Increase the DB_CACHE_SIZE initialization parameter
B. Rebuild the table using Automatic Segment Space Management (ASSM) and increase PCTFREE
C. Switch the database from ARCHIVELOG to NOARCHIVELOG mode
D. Move the tablespace to a disk group with lower latency spindles
🟢 Correct answer B. Option
🔴 RATIONALE: 'Buffer busy waits' on data blocks occur when multiple sessions attempt to access or modify the same data block simultaneously. Using
Automatic Segment Space Management (ASSM) inherently manages free space inside segments using bitmaps rather than free lists, reducing block
contention. Increasing PCTFREE ensures that fewer rows are packed into a single block, distributing concurrent insert and update operations across multiple
blocks and directly lowering concurrent block-level locking conflicts. Increasing cache size or moving disks does not resolve logical block concurrency issues.
Question 3
To comply with internal data privacy regulations, a database administrator must track all changes made to financial records in the database, capturing the
database user, the OS user, the terminal, and the exact SQL statement executed. Which Oracle feature satisfies this regulatory requirement with minimal
performance overhead?
A. Fine-Grained Auditing (FGA)
B. Standard Database Auditing with AUDIT_TRAIL=DB
C. Creating a database AFTER ALTER trigger on the schema
D. Implementing Oracle LogMiner on redolog archives
🟢 Correct answer A. Option
🔴 RATIONALE: Fine-Grained Auditing (FGA) allows administrators to audit specific data access and modifications based on policies attached to tables or
views. FGA automatically captures the exact SQL statement text, bind variables, database user, operating system user, and terminal information, writing this
data directly to the audit trail. FGA is highly optimized for performance compared to row-level triggers, and standard database auditing does not natively
capture the full SQL statement text for standard DML operations without comprehensive, high-overhead configurations.
Question 4
A junior administrator accidently drops an internal lookup table 'REG_CODES' from a production pluggable database (PDB) at 14:00 hours. It is now 14:30
hours. The database is in ARCHIVELOG mode, and FLASHBACK MARKET is disabled. What is the most efficient way to recover this table without impacting
the rest of the database?
A. Perform an RMAN point-in-time recovery of the entire container database (CDB)
B. Execute an RMAN table recovery command specifying the dropped table and the target time
C. Use Flashback Database to revert the entire PDB to 13:59 hours
D. Restore the tablespace containing the table to a separate auxiliary instance and export the data
🟢 Correct answer B. Option
🔴 RATIONALE: In modern Oracle versions, RMAN provides the ability to recover specific tables or table partitions to a past point in time directly from
backups. RMAN automates the process by creating an auxiliary instance, restoring the required tablespace, recovering it to the designated point in time, and
then exporting/importing the table back to the source database. This avoids taking the entire PDB or CDB offline, making it far more efficient than a full point-
in-time database recovery or manual auxiliary instance setups. Flashback Database cannot be used because it is disabled.
Question 5
An Oracle Database instance fails suddenly due to a power outage on the hosting server. Upon restarting the server and instance, which background process
is primarily responsible for rolling back uncommitted transactions and ensuring data consistency?
, A. PMON
B. SMON
C. DBWn
D. LGWR
🟢 Correct answer B. Option
🔴 RATIONALE: The System Monitor (SMON) background process performs instance recovery at database startup. This includes rolling forward changes in
the online redo logs that were not yet written to the data files (redo phase) and subsequently rolling back transactions that were active but uncommitted at the
time of the crash (undo phase). PMON handles process cleanup for failed user sessions. DBWn writes dirty blocks from the buffer cache to disk, and LGWR
writes redo entries to disk.
Question 6
You need to configure network connectivity for an Oracle database so that client applications can connect via a connection pool. Which file on the database
server must be configured to define the listener port, protocol, and database service registrations?
A. tnsnames.ora
B. sqlnet.ora
C. listener.ora
D. hosts
🟢 Correct answer C. Option
🔴 RATIONALE: The listener.ora file is the configuration file for the Oracle Net Listener process residing on the database server. It defines the protocol
addresses, ports, and specific database service names that the listener listens on to receive incoming client connection requests. The tnsnames.ora file is
primarily configured on the client side to map connection strings to listener addresses, and sqlnet.ora configures general network software parameters.
Question 7
A business application requires a high-performance database setup where read queries never block write operations, and write operations never block read
operations. How does the Oracle database engine natively handle this concurrency requirement?
A. By utilizing table-level locks for all DML statements
B. Through multi-version read consistency using Undo data
C. By enforcing serializable isolation levels by default for all sessions
D. Through the aggressive use of latching mechanisms in the shared pool
🟢 Correct answer B. Option
🔴 RATIONALE: Oracle Database uses Undo data to implement multi-version read consistency. When a transaction modifies a block, the old data values are
written to the Undo segments. When another session executes a read query against that same data concurrently, Oracle reads the committed data from the
Undo segments to present a point-in-time consistent view of the data. This completely prevents readers from blocking writers and writers from blocking
readers.
Question 8
An organization must ensure that all sensitive columns, such as credit card numbers, are encrypted at rest on the storage subsystem to prevent data exposure
via stolen backup tapes or compromised disk drives. Which Oracle feature should be implemented?
A. Virtual Private Database (VPD)
B. Transparent Data Encryption (TDE)
C. Oracle Data Masking and Subsetting
D. Data Redaction
🟢 Correct answer B. Option
