OCP Oracle 10g Admin II - Ch 5: Understanding the Flashback Database

Review Questions
1. What type of recovery is the Flashback Database best suited for? (Choose all that apply.)
A. User error
B. Physical corruption
C. Logical corruption
D. Media failure
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Ans: A, C.
A Flashback Database recovery is best suited for a user error such as a truncated table or a logical corruption like an incomplete batch transaction affecting many tables. Media recovery situations cannot be performed with the Flashback Database recovery method.

2. Flashback Database recovery can recover from which of the following failure scenarios?
A. Loss of control file
B. Dropping a tablespace through RESETLOGS
C. A user error that resized datafiles to a smaller size
D. A large truncated table or group of tables
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Ans: D.
A Flashback Database recovery can recover a large truncated table or group of tables.

3. What new background process is responsible for writing before block images
and recovering from the Flashback Database log?
A. RWVR
B. RVWR
C. RWRV
D. RVRW
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Ans: B.
The RVWR process is responsible for writing the "before" image information to the Flashback Database log. The Flashback Database log is read to perform the Flashback Database recovery.

4. What are the benefits of the flash recovery area in the recovery and backup process?
A. Recovery efficiency is improved because all files are stored on tape media for fast access.
B. Recovery efficiency is improved because the files are stored in multiple locations.
C. Recovery efficiency is improved because the files are stored in one location on tape.
D. Recovery efficiency is improved because the files are stored in one location on disk.
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Ans: D.
The flash recovery area is a centralized storage area for backups on disk. This allows for a more efficient recovery process because the required files are in one location and are stored on disk instead of tape.

5. Where is information about the status of the flash recovery area displayed?
(Choose all that apply.)
A. Alert log
B. Background trace files
C. V$_OUSTANDING_ALERTS
D. DBA_OUTSTANDING_ALERTS
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Ans: A, D.
The Alert log reports space usage and other information about the flash recovery area. DBA_OUTSTANDING_ALERTS also show the information state of the flash recovery area.


6. How is the size of the flash recovery area determined? (Choose all that apply.)
A. The size is automatically allocated at 2 gigabytes.
B. Using the ALTER SYSTEM command to dynamically set the size.
C. With the initialization parameter DB_RECOVERY_FILE_DEST_SIZE.
D. Using the ALTER TABLESPACE command.
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Ans: B, C.
The flash recovery area can be determined by either setting the initialization
parameter DB_RECOVERY_FILE_DEST_SIZE or using the ALTER SYSTEM command.

7. What type of backup commands can the flash recovery area be used for?
(Choose all that apply.)
A. BACKUP COPY
B. BACKUP IMAGE
C. BACKUP
D. BACKUPSET
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Ans: A, C.
The flash recovery area supports both the BACKUP and BACKUP COPY commands, which perform backup sets and image copies.

8. The flash recovery area space utilization and stored files can be identified by what method?
A. DBA_OUTSTANDING_ALERTS
B. V$OUTSTANDING_ALERTS
C. V$RECOVERY_FILE_DEST
D. DBA_RECOVERY_FILE_DEST
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Ans: C.
The dynamic view V$RECOVERY_FILE_DEST displays the space utilization and the
amount of files that make up the flash recovery area.

9. What parameter determines the length of time that the Flashback Database will
store "before" images that can be used in the recovery process?
A. DB_FLASHBACK_RETENTION_POLICY
B. DB_FLASHBACK_RETENTION_TIME
C. DB_FLASHBACK_RETENTION_STORE
D. DB_FLASHBACK_RETENTION_TARGET
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Ans: D.
The DB_FLASHBACK_RETENTION_TARGET parameter determines how much data is available to recover.

10. How is the DB_FLASHBACK_RETENTION_TARGET parameter measured?
A. By SCN
B. By redo log sequences
C. By time in minutes
D. By redo log sequence and threads
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Ans: C.
DB_FLASHBACK_RETENTION_TARGET is a parameter that is measured in minutes. This value determines how many minutes the Flashback Database should write data before this data gets overwritten.

11. To enable the Flashback Database, what must be done to the database?
(Choose all that apply.)
A. It must be mounted.
B. It must be opened with RESETLOGS.
C. The flash recovery area must be created.
D. The database must be in ARCHIVELOG mode.
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Ans: A, C, D.
To enable the Flashback Database, the flash recovery area must be created. The database must be mounted but not opened to turn on the Flashback Database. The database must also be in ARCHIVELOG mode.

12. When using the Flashback Database in a recovery situation, what information would be useful to know? (Choose all that apply.)
A. Information about the smallest SCN number that is stored in the Flashback Database log
B. Information about the earliest timestamp that is stored in the Flashback Database log
C. Information about the greatest SCN number that is stored in the Flashback Database log
D. Information about the latest timestamp that is stored in the Flashback Database log
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Ans: A, B.
The earliest timestamp and smallest SCN will tell you how far back you can recover the database. These values can be queried by the V$FLASHBACK_DATABASE_LOG dynamic view.

13. How can you determine if the Flashback Database is turned on?
A. Query the DBA_FLASHBACK_DATABASE view.
B. Query the V$DATABASE dynamic view.
C. Check the initialization parameters.
D. Check the alert log.
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Ans: B.
The V$DATABASE dynamic view has a new column called FLASHBACK_ON, which contains a value of YES or NO.


14. Which of the following views can determine how much space you may need in the future in the Flashback Database logs?
A. V$DATABASE
B. V$FLASHBACK_DATABASE_STAT
C. V$FLASHBCK_DATABASE_LOG
D. DBA_FLASHBACK_LOG
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Ans: B.
The V$FLASHBACK_DATABASE_STAT dynamic view shows the daily growth and utilization of the Flashback Database log. You can match daily activities to the daily utilization of the Flashback Database log.

15. What is the default size of a redo log file created in the flash recovery area?
A. 100MB
B. 150MB
C. 10MB
D. 50MB
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Ans: A.
The default size of a redo log file created in the flash recovery area is 100MB.

16. Which initialization parameter will create archive logs to the flash recovery area?
A. ARCHIVE_LOG_DEST
B. ARCHIVE_DUPLEX_DEST
C. ARCHIVE_LOG_DEST_n
D. LOG_ARCHIVE_DEST_n
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Ans: D.
The LOG_ARCHIVE_DEST_n is the only initialization parameter that will create or write archive logs to the flash recovery area.

17. Which database files are permanently stored in the flash recovery area?
(Choose all that apply.)
A. Datafiles
B. RMAN files
C. Control files
D. Current online redo logs
E. Archive logs
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Ans: C, D.
Control files and redo logs area considered permanent files in the flash recovery area. These files are not made obsolete and deleted, even when backed up to tape.

18. Which files will not be backed up in the flash recovery area when you're using
the BACKUP RECOVERY AREA and BACKUP RECOVERY FILES commands?
(Choose all that apply.)
A. Control files
B. Redo logs
C. Datafiles
D. Permanent files
E. Flashback logs
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Ans: A, B, D, E.
The flash recovery area will not back up redo log files, control files, or
flashback logs with the BACKUP RECOVERY AREA and BACKUP RECOVERY FILES
commands. Permanent files are considered to be current online redo logs and control
files.

19. What is responsible for applying the "before" images to the database during a Flashback Database recovery?
A. LGWR
B. SMON
C. DBWR
D. RVWR
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Ans: D.
The RVWR process is responsible for writing the "before" images to the
Flashback Database log. This process is also responsible for applying these to the
database during a recovery.

20. What administrative database activity cannot be undone with the Flashback Database recovery?
A. Dropped table
B. Dropped user
C. Resized datafiles to smaller size
D. Dropped tablespace
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Ans: C.
Resizing of a tablespace or datafiles to a smaller size cannot be undone with Flashback Database recovery.