Chapter 3 - Recovering From Non-Critical Losses
Review Questions
1. Which of the following statements is true about non-critical losses?
A. Non-critical losses require media recovery.
B. Non-critical losses have a severe impact on database operations.
C. Non-critical losses can be resolved quickly with little impact to
database operations.
D. Non-critical losses require the use of the RECOVER command.
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Non-critical losses have little impact on database operations if resolved properly.
Ans: C.
2. Which of the following statements is true about temporary tablespaces?
A. Temporary tablespaces most often contain some permanent objects.
B. Temporary tablespaces are responsible for storing temporary or sort
statements.
C. Temporary tablespaces must be recovered with the RECOVER command.
D. Temporary tablespaces cannot be managed locally.
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Temporary tablespaces are responsible for storing temporary or sort segments.
These are used in the sorting of select statements or in building indexes.
Ans: B.
3. Why is a missing tempfile considered a non-critical recovery situation?
A. The tempfile is dictionary managed and can only contain some
permanent objects.
B. The tempfile is locally managed and can only contain some temporary
objects.
C. The tempfile is locally managed and can only contain temporary
objects.
D. The tempfile is dictionary managed and can only contain temporary
objects.
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C
4. How can you resolve a missing temporary tablespace quickly? (Choose all that
apply.)
A. Recover the tablespace immediately because restoring is not needed.
B. Restore the tablespace from disk and not from tape.
C. Run CREATE TEMPORARY TABLESPACE and then ALTER DATABASE to
the new temporary tablespace.
D. If a temporary tablespace exists, then run ALTER DATABASE to the
existing temporary tablespace.
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Ans C.
A missing tempfile can be re-created with the create tablespace command.
Because the tempfile is locally managed and contains no permanent data, no restoring
or recovering is needed. Therefore recovery can occur quickly with minimal impact
to database operations.
5. What must be done to recover a missing redo log file member?
A. First perform a ALTER DATABASE DROP LOGFILE MEMBER filename
and then ALTER DATABASE ADD LOGFILE MEMBER filename on the
missing logfile member.
B. Perform ALTER DATABASE ADD LOGFILE MEMBER filename on the
missing logfile.
C. Nothing is required if you have multiplexed redo logs.
D. Nothing is required if you do not have multiplexed redo logs.
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The missing redo log must first be dropped even though it doesn't exist physically
in the file system. This removes the redo log metadata from the data dictionary. Next
the log can be added back to database.
Ans: A.
6. How would you know if you have lost a mirrored redo log member?
A. The database would hang.
B. The archive process would stop working.
C. The alert log would display an error, and the database would hang.
D. The alert log would display an error, and the database would process
the archive logs.
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If your database has mirrored redo logs and a member is deleted, the database will
function as normal. The error signaling that a log member has been deleted would be
written to the alert log.
Ans: D
7. What happens if the current or active online redo log group has a new member
added?
A. Nothing, the redo log member will be added.
B. The redo log member will not be added because the log group is
actively recording transactions.
C. The redo log member will be added, but it will be out of sync until a
log switch occurs.
D. The redo log member will be added, but it will be empty.
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The redo log member will not be added to the current or active redo log group.
Oracle will not allow this because transactions are actively being written to the redo
log group.
Ans: B.
8. What happens when you are recovering a temporary tablespace by switching to
another available tablespace? (Choose all that apply.)
A. The new temporary tablespace is made available if the tablespace is
permanent.
B. The new temporary tablespace is made available if the tablespace is
temporary.
C. You will receive an ORA-12904 error if the available tablespace is
temporary.
D. You will receive an ORA-12904 error if the available tablespace is
permanent.
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You must use the ALTER DATABASE DEFAULT TEMPORARY TABLESPACE table
name command on a temporary tablespace or you will receive an ORA-12904 error.
Ans: B. D.
9. How can you rebuild the objects in the index tablespace most efficiently?
A. Recover the index from tape.
B. Rebuild the index with LOGGING.
C. Rebuild the index with NOLOGGING.
D. Rebuild the index in parallel with NOLOGGING.
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Rebuilding an index in parallel with NOLOGGING is the most efficient method of
building an index to minimize the impact on database operations. You must be
cautious not to use extensive server resources when you don't use the parallel rebuild
option.
Ans: D.
10. What should be updated and readily accessible in case of a non-critical loss of
a tablespace?
A. Temporary segments
B. SELECT statements using sorting
C. Current index scripts
D. Create table scripts
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The index scripts must be current and stored locally so they can be accessed
quickly and easily during an index tablespace rebuild.
Ans: C.
11. Which type of tablespace contains static data?
A. Read-only tablespace
B. Index tablespace
C. Read-write tablespace
D. Temporary tablespace
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The read-only tablespace contains only static or non-changing data.
Ans: A.
12. What is the result of starting an Oracle database with a missing read-only
tablespace? (Choose two.)
A. The database opens normally.
B. The database only mounts.
C. An ORA-01157 cannot identify datafile halts the database
from opening error occurs.
D. The database functions normally, and the read-only tablespace is static.
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The database will stop at the mount stage. This is due to the ORA-01157 error.
Ans: B, C
13. When connecting to an Oracle database locally to perform administrative
functions, you are connecting with what access privilege?
A. SQL*Net
B. IPC
C. SYSDBA
D. SYSOPER
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Ans: B. IPC is the method that the local administrative access uses to connect to the
database.
(??)
14. What is the proper way of creating a password supporting up to 10 users?
A. orapwd file=orapwORA101T password=syspass users=10
B. orapwd file=orapwORA101T password=syspass entry=10
C. orapwd file=orapwORA101T password=syspass entries=10
D. orapass file=orapwORA101T password=syspass entries=10
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The correct command to create a password file that supports 10 users is orapwd
file=orapwORA101T password=syspass entries=10.
Ans: C.
15. Which initialization parameter is required for remote access to the database?
A. REMOTE_LOGIN_PASSWORDFILE
B. BREMOTE_LOGIN_PASSWORD_FILE
C. REMOTE_PASSWORD_FILE
D. REMOTE_LOGIN_FILE
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The initialization parameter required for remote access is
REMOTE_LOGIN_PASSWORDFILE.
Ans: A.
16. Which directory should the password file be stored in to function properly?
(Choose all that apply.)
A. $ORACLE_HOME
B. $ORACLE_HOME/dbs
C. C:\$ORACLE_HOME\database
D. $ORACLE_SID
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The $ORACLE_HOME/dbs is the Unix location for the password file, and
C:\$ORACLE_ HOME\database is the Windows location for the password file.
Ans: B, C.
17. Before running the ORAPWD utility to generate a password file, what should
be done?
A. Start the database but make sure it isn't open.
B. Start up the database.
C. Start up the database in MOUNT mode.
D. Shut down the database.
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The database should be shut down before running the ORAPWD utility.
Ans: D.
18. What do local connections to an Oracle database rely on for security and
authentication of the user?
A. Password file
B. Database password
C. Operating system password
D. Listener password
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Local connections are secured by the operating system password logging on to an
administrative account such as Oracle user in Unix and administrator in Windows.
Ans: C.
19. The main reason that you need to restore and use the RECOVER command on a
tablespace that was backed up read-write and converted to read-only is due to
what? (Choose all that apply.)
A. The checkpointing process has changed the control file.
B. There have been changes to the tablespace.
C. The tablespace file header has been changed.
D. Read-only tablespaces require the RECOVER command.
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Ans: A, B, C. The scenario of read-write to read-only tablespace requires the use of the
RECOVER command, which will apply necessary redo changes to make the tablespace
consistent with the control file. The checkpointing operation of Oracle will change
the control file, and the header of the read-only tablespace will be modified, which
equates to changes in the tablespace.
20. Which situation is considered a non-critical loss to the database? (Choose all
that apply.)
A. Loss of redo log group before archived
B. Loss of current or active redo member
C. Loss of archive log
D. Loss of current or active redo group
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Ans: B, C.
A non-critical loss should have limited impact on database operations. This
means that incomplete recovery or media failure scenarios need to be performed. A
loss of a redo group before archived will require incomplete recovery, which is the
same as the loss of current or active redo log group. The current or active member or
loss of archive will not significantly impact operations. A backup can be performed
to eliminate the need for the archive log, and the database will function normally with
the loss of a redo log member.
