1z0-043 lesson 6 Flashback

终于完成了 15:19 2009 05 04

是否显示我的答案
是否显示书上的答案和我的注释



1.
12. You are working on an Oracle Database 10g database. You enabled the Flashback Database feature. Which two statements regarding flashback logs are true? (Choose two.)
A. Flashback logs are not archived.
B. Flashback logs are maintained in redo log files.
C. Flashback logs are maintained in the Flash Recovery Area.
D. Flashback logs are used to maintain Flashback Database related errors.
E. Flashback logs need to be cleared manually after you disable Flashback Database.

AC

AC

A 教材6-15 Note: Flashback Database logs are not archived.
C 教材6-18
D 6-16 You can disable Flashback Database with the ALTER DATABASE FLASHBACK OFF command. As a result, all existing Flashback Database logs are deleted automatically.

Mon May  4 10:45:11 2009
alter database flashback off
Mon May  4 10:45:11 2009
Stopping background process RVWR
Deleted Oracle managed file /home/oracle/app/oracle/oradata/test/flash_recovery_area/TEST/flashback/o1_mf_4zwro18y_.flb
Deleted Oracle managed file /home/oracle/app/oracle/oradata/test/flash_recovery_area/TEST/flashback/o1_mf_4zx85hg1_.flb
Flashback Database Disabled
Completed: alter database flashback off

自动删除闪回日志

2.
13. You executed the following query:
SELECT operation, undo_sql, table_name FROM flashback_transaction_query;
Which statement is correct regarding the query output?
A. It would return information regarding only the last committed transaction.
B. It would return only the active transactions in all the undo segments in the database.
C. It would return only the committed transactions in all the undo segments in the database.
D. It would return both active and committed transactions in all the undo segments in the database.
E. It would return information regarding the transactions that began and were committed in the last 30 minutes.

D

D

D PDF教材10-23 The first example returns information about all transactions, both active and committed, in
all undo segments in the database.

3.
26. Exhibit: You want to configure the Flashback Database feature and retain flashback logs for three days. The steps used in this process are displayed in the exhibit. In what sequence would you need to perform these steps to enable the Flashback Database feature?

A. D, C, A, B, E
B. D, A, C, B, E
C. B, D, C, E, A
D. D, B, E, C, A

A

A

教材6-16

4.
42. Exhibit: A user has inserted wrong department data in the DEPT3 table in the USERS tablespace. You use the Flashback Table functionality to rectify the erroneous inserts. While performing the recovery, you choose 2004343 as the Flashback SCN. Which two statements are correct in this scenario? (Choose two.)

A. Only the row with DEPARTMENT_ID 290 would be flashed back.
B. The rows with DEPARTMENT_ID 290 and 300 would be flashed back.
C. The rows with DEPARTMENT_ID 290 and 280 would be flashed back.
D. You would have taken the USERS tablespace offline before starting the Flashback Table operation.
E. You would have enabled row movement for the DEPT3 table before starting the Flashback Table operation.

B? E

BE

B

conn / as sysdba
alter database add supplemental log data;
select supplemental_log_data_min from v$database;
grant select on v_$database to a;
conn a/a
select current_scn from v$database;
drop table t;
create table t (a int, b int);
--wait 10 secs 这里得等一会儿, 否则create table后立刻insert,commit, 闪回版本查询那些伪列都是空的
insert into t values (1,1);
commit;
insert into t values (2,1);
commit;
insert into t values (3,1);
commit;
insert into t values (10,2);
commit;
insert into t values (11,2);
commit;

闪回版本查询

select versions_startscn, versions_starttime,
       versions_endscn,versions_endtime,
       versions_xid,versions_operation,
       a
  from a.t
       versions between scn minvalue and maxvalue
 where b=1;

SQL> select versions_startscn, versions_starttime,
       versions_endscn,versions_endtime,
       versions_xid,versions_operation,
       a
  from a.t
       versions between scn minvalue and maxvalue
 where b=1;
  2    3    4    5    6    7
VERSIONS_STARTSCN VERSIONS_STARTTIME                                                          VERSIONS_ENDSCN
----------------- --------------------------------------------------------------------------- ---------------
VERSIONS_ENDTIME                                                            VERSIONS_XID     V          A
--------------------------------------------------------------------------- ---------------- - ----------
          2438054 05-MAR-09 10.28.10 AM
                                                                            07002B0098020000 I          3

          2438052 05-MAR-09 10.28.10 AM
                                                                            0A001A008D020000 I          2

          2438050 05-MAR-09 10.28.04 AM
                                                                            050004009A020000 I          1


SQL>

闪回表

select * from t as of scn 2438052;
select current_scn from v$database;
alter table t enable row movement;
flashback table t to scn 2438052;
select * from t;

SQL> select * from t as of scn 2438052;

         A          B
---------- ----------
         1          1
         2          1

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
    2438077

SQL> alter table t enable row movement;

Table altered.

SQL> flashback table t to scn 2438052;

Flashback complete.

SQL> select * from t;

         A          B
---------- ----------
         1          1
         2          1

SQL>

答案B不对, 不包括SCN那条记录, 应该是Only the row with DEPARTMENT_ID 300 would be flashed back.

E PDF10-29 Before issuing a FLASHBACK TABLE command, it is therefore necessary to enable row movement on the impacted tables.

5.
45. On Tuesday, a junior DBA dropped an important application user account, whose schema has important tables. You are asked to recover all the objects in the schema. On investigation, you find that the user account was dropped at 11:00 a.m. and Sunday's backup is the most recent backup.Which flashback feature would you use?
A. Flashback Drop
B. Flashback Table
C. Flashback Database
D. Flashback Version Query
E. Flashback Transaction Query

C

C

只有闪回数据库了

6.
47. Because of data loss, you decided to perform a Flashback Database operation using the following command:
SQL> FLASHBACK DATABASE TO TIMESTAMP(SYSDATE - 5/24);
Which two statements are true? (Choose two.)
A. SYSDATE should not be used with TIMESTAMP.
B. The database must have multiplexed redo log files.
C. The database must be in the MOUNT state to execute the command.
D. The database must be opened with the RESETLOGS option after the flashback operation.
E. The entire database needs to be restored from the most recent backup before the flashback operation.

CD ?

CD

A.SQL命令可以这么用 教材6-19
C.教材6-19 The database must be mounted in exclusive mode to issue the FLASHBACK DATABASE command and must be opened with the RESETLOGS option when finished
D.同上

7.
61. You are working in an online transaction processing (OLTP) environment. You realize that the salary for an employee, John, has been accidentally modified in the EMPLOYEES table. Two days ago, the data was in the correct state. Flashback logs generated during last two days are available in the flash recovery area. Which option would you choose to bring the data to the correct state while ensuring that no other data in the same table is affected?
A. perform point-in-time recovery
B. perform a Flashback Table operation to restore the table to the state it was in two days ago
C. perform a Flashback Database operation to restore the database to the state it was in two days ago
D. perform Flashback Versions Query and Flashback Transaction Query to determine all the necessary undo SQL statements, and then use them for recovery

D

D

这题不严谨, 都过去2天了, 闪回版本查询不一定能得到保证

8.
64. These are the details about V$FLASHBACK_DATABASE_STAT:
SQL> DESC v$FLASHBACK_DATABASE_STAT
Name Null? Type
------------- -------- --------------
BEGIN_TIME DATE
END_TIME DATE
FLASHBACK_DATA NUMBER
DB_DATA NUMBER
REDO_DATA NUMBER
ESTIMATED_FLASHBACK_SIZE NUMBER
Which two statements regarding the V$FLASHBACK_DATABASE_STAT view are true? (Choose two.)
A. BEGIN_TIME is the time at which Flashback logging is enabled.
B. END_TIME is the time at which the query is executed on the view.
C. REDO_DATA is the number of bytes of redo data written during the interval.
D. This view contains information about flashback data pertaining to the last 24 hours.
E. FLASHBACK_DATA is the amount of flashback data generated since the database was opened.

CD

CD

见
教材6-27 和 V$FLASHBACK_DATABASE_STAT

9.
70. Why would you use the following FLASHBACK TABLE command? FLASHBACK TABLE emp TO TIMESTAMP ('11:45'.'hh12:mi');
A. to undo the changes made to the EMP table since the specified time
B. to restore the EMP table that was wrongly dropped from the database
C. to view the transactions that have modified the EMP table since the specified time
D. to view the changes made to the EMP table for one or more rows since the specified time

A

A

容易

10.
72. By using the transaction identifier provided by ______ for a particular row change, you can use the Flashback Transaction Query to see the operation performed by the transaction.
A. Flashback Table
B. Flashback Database
C. Flashback Version Query
D. The RMAN REPORT command
E. The DBA_PENDING_TRANSACTIONS view

C

C

PDF教材10-24
"By using the transaction identifier provided by the version query, for a particular row version, you can use Flashback Transaction Query to see exactly what operations were performed by the transaction and the necessary SQL statements to executed to undo those changes."

11.
76. Exhibit, Viewing the Exhibit and examine the Flashback Database architecture. Identify the missing component (shown with a "?" in the Flashback Database architecture.

A. DBWn
B. RVWR
C. ARCH
D. RECO
E. TRWR

B

B

教材6-15

12.
79. You disabled the Flashback Database feature by using the following command:
SQL> ALTER DATABASE FLASHBACK OFF;
What would be the effect of this command on the existing flashback logs?
A. Flashback logs are not deleted.
B. Flashback logs are deleted automatically.
C. Flashback logs are deleted only if you are using Recovery Manager (RMAN)
D. Flashback logs are deleted only if you are using Oracle Manager Files (OFM)
E. Flashback logs are deleted only if you are using Automatic Storage Management (ASM)

B?

B

教材6-16
"You can disable Flashback Database with the ALTER DATABASE FLASHBACK OFF command. As a result, all existing Flashback Database logs are deleted automatically."

13.
85. A data file become corrupted in your database due to bad sectors on the disk. Because of corruption, you lost all the important tables in that data file. Which method would you use for recovery?
A. Flash back all the tables in the data file, one by one.
B. Restore the data file to a new location and perform a media recovery.
C. Flash back the database, there is no need to restore the data file.
D. Restore the data file from the most recent backup and flash the database.

B

B

恢复数据文件然后应用重做日志

14.
86. For which two SQL statements can you use the Flashback Table feature to revert a table to its previous state? (Choose two)
A. UPDATE TABLE
B. CREATE CLUSTER
C. TRUNCATE TABLE
D. ALTER TABLE MOVE
E. INSERT INTO...VALUES
F. ALTER TABLE...DROP COLUMN
G. ALTER TABLE...DROP PARTITION

AE

AE

不能是DDL
教材上没找到? 可我记得哪儿说来的呀

15.
90.For which purposes would you use the Flashback Transaction Query feature? (Choose all that apply)
A. To recover a dropped table.
B. To recover a dropped schema.
C. To recover data from a truncated table.
D. To view changes made by all the transactions during a given period of time.
E. To view changes made by a single transaction during a given period of time.

D

DE

PDF教材10-22
"You can use the FLASHBACK_TRANSACTION_QUERY view to determine all of the necessary SQL statements that can be used to undo the changes made by a specific transaction, or during a specific period of time"

16.
101. You executed the following query in your database:
SELECT oldest_flashback_scn, oldest_flashback_time
FROM V$FLASHBACK_DATABASE_LOG;
What would you determine from the output?
A. The time when the last flashback operation in your database was performed.
B. The time when the first flashback operation in your database was performed.
C. A list of flashback operations performed in your database using SCN and time.
D. The approximate time and the lowest system change number (SCN) to which you can flash back your database.

D

D

教材6-26
"OLDEST_FLASHBACK_SCN and OLDEST_FLASHBACK_TIME display the approximate lowest SCN and time to which you can flash back your database."

17.
103. Exhibit: View the Exhibits.
You performed operations on the DEPT4 table as shown in the Exhibit. When you perform the Flashback Versions Query, you find that the first two updates are not listed. What could be the reason?


A. The row movement is not enabled on the table.
B. The first two updates were not explicitly committed.
C. The Flashback Versions Query lists only the most recent update.
D. The Flashback Versions Query stops producing rows after it encounters a time in the past when the table structure was changed.

D

D

因为有个alter语句

PDF教材10-21
"The VERSIONS clause in a SELECT statement cannot produce versions of rows across the DDL statements that change the structure of the corresponding tables. This means that the query stops producing rows once it hits a time in the past when the table was changed."

18.
105. Exhibit: View the Exhibit. You have more than one table in the recycle bin having the same original name, DEPT2. You do not have any table with the name DEPT2 in your schema. You executed the following command:PURGE TABLE dept2; Which statement is correct in this scenario?

A. All the tables having the same original name as DEPT2 will be purged from the recycle bin.
B. The table with dropscn = 1928151 (oldest dropscn) will be purged from the recycle bin.
C. The table with dropscn = 1937123 (most recent dropscn) will be purged from the recycle bin.
D. None of the tables will be purged because there are multiple entries with the same original name in the recycle bin.

B

B

PDF教材10-13
"For the PURGE TABLE and PURGE INDEX commands, if you specify an original name and the recycle bin contains more than one object of that name, then the object that has been in the recycle bin the longest is purged first (First In First Out)."

19.
111. You are working in an online transaction processing (OLTP) environment. You used the FLASHBACK TABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command, the System Change Number (SCN) was 663571. After flashing back the CUSTOMERS table, you realize that the table is not in the correct state and the resultant changes are not what you had desired. So, you need to reverse the effects of the FLASHBACK TABLE command while ensuring that:
a) No other user data in the database is affected.
b) The operation takes the minimum possible time
Which option would you choose?
A. Use ROLLBACK command with SCN 663571.
B. Perform Flashback Transaction Query with SCN 663571.
C. Execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571.
D. Execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571.

D

D

PDF教材10-30

20.
114. By mistake, you ran the batch job (for updating the BILL_DETAILS table) twice. You are not sure which rows in the BILL_DETAILS table were affected. You need to identify:
a) A list of changes made along with the transaction identifier of each change.
b) The necessary SQL statements to undo the erroneous changes.
Which option would you choose?
A. RMAN only.
B. Flashback Table only.
C. Flashback Version Query only.
D. Flashback Database and Flashback Transaction Query.
E. Flashback Version Query and Flashback Transaction Query.

E

E

闪回版本查询查出事务号, 闪回事务潺寻查出撤销语句

21.
130. You enabled the flashback logging feature, but you have not specified the location of the flash recovery area. Which location would be used as the default location for the flash recovery area?
A. The location used for control files.
B. The location used for redo log files.
C. The location set by using $ORACLE_BASE.
D. The location set by using $ORACLE_HOME.
E. The location set by using CORE_DUMP_DEST.
F. The location set by using BACKGROUND_DUMP_DEST.

C ?

C

教材6-18
"The default location for the flash recovery area is $ORACLE_BASE."

22.
143. What are the prerequisites for enabling Flashback Database? (Choose all that apply.)
A. The database must be started in the MOUNT EXCLUSIVE state.
B. The database must have multiplexed control files.
C. The database must be opened by using a text-based parameter file instead of a server parameter file (SPFILE).
D. The database must be in ARCHIVELOG mode.
E. The database must be in the NOMOUNT state.
F. The database must be opened in RESTRICTED mode.

ADF

AD

F.不能打开, 我看错了
教材6-16 6-17

23.
159. You executed the following FLASHBACK TABLE command:
FLASHBACK TABLE emp TO TIMESTAMP ('11:45','hh12:mi');
Which two statements are correct? (Choose two.)
A. The FLASHBACK TABLE statement will not be written to the alert log file.
B. The EMP table that was dropped by mistake from the database will be restored.
C. The changes made to the EMP table since the specified time will be undone.
D. The FLASHBACK TABLE statement will not maintain the existing indexes on the EMP table.
E. The FLASHBACK TABLE statement will be executed within a single transaction.
F. The list of transactions that have modified the EMP table since the specified time will be displayed.

CE

CE

PDF教材10-27

24.
160. Which two statements are correct regarding the Flashback Versions Query feature? (Choose two.)
A. You can use this feature to identify the committed versions of the rows, but not the uncommitted versions.
B. You can use this feature to identify the versions of V$ views.
C. You can use this feature to identify the inserts, deletes, and updates performed on a particular row but not the data definition language (DDL) operations performed on the table.
D. You can use this feature for a table only if row movement is enabled for the table.
E. You can use this feature to identify the versions of external and fixed tables.

AC

AC

A. 看不到未提交的
C. 看不到DDL语句
D. 闪回表需要开启row movement
PDF教材10-17 10-31

25.
168. You are working on an Oracle Database 10g database that operates in the ARCHIVELOG mode. At 06:00 p.m., you discovered that a table in the SYSTEM tablespace that does not belong to the data dictionary was dropped at 03:00 p.m. What would you do to recover the table?
A. use the Flashback Transaction Query feature to identify the relevant SQL statement and use it to undrop the table
B. restore the entire database from the most recent backup and open it
C. recover the table by using the Flashback Table feature
D. perform point-in-time recovery to recover the table

D

D

PDF教材10-31
"Flashback Table cannot be performed on system tables, remote tables, and fixed tables."

26.
177. On Monday, you dropped the DEPT table from your schema and then you re-created the DEPT table in your schema. On Wednesday, you have a requirement to restore the DEPT table from the recycle bin. Which statement is correct?
A. You cannot restore the DEPT table by using the Oracle Flashback Drop feature because a table with the name DEPT already exists in your schema.
B. You can restore the DEPT table by using the Oracle Flashback Drop feature, provided you use the RENAME TO clause.
C. You cannot restore the DEPT table by using the Oracle Flashback Drop feature because the contents of the recycle bin are purged every 12 hours by default.
D. You can restore the DEPT table by using the Oracle Flashback Drop feature and a system-generated name will be assigned to the restored table.

B

B

可以改名
教材6-7

=====

27.
16. Where are the flashback database logs stored? (Choose all that apply.)
A. Flashback database logs are stored in the flash recovery area.
B. Flashback database logs are stored at the location specified by the FLASH_DATABASE_LOG_DEST parameter.
C. Flashback database logs are stored at the location specified by the DB_RECOVERY_FILE_DEST parameter.
D. Flashback database logs are stored at the location specified by the FLASH_DATABASE_RETENTION_TARGET parameter.

B ?

A, C. The flashback database logs must be stored in the flash recovery area. The actual location
in the flash recovery area is determined by the DB_RECOVERY_FILE_DEST parameter. See
Chapter 5 for more information.

教材6-18
这题竟然错了, 该死

28.
17. Which of the following statements are correct regarding warnings at flash recovery thresholds? (Choose all that apply.)
A. At 90 percent, there is a full warning and obsolete files are removed.
B. At 85 percent, there is a full warning.
C. At 95 percent, there is a full warning and obsolete files are removed.
D. At 95 percent, there is a full warning.

BC??

A, D. At 90 percent full, a warning is sent to the alert log, and obsolete files are removed. At
95 percent full, warnings are set to the alert log. See Chapter 5 for more information.

哦

29.
20. What command is equivalent to the DROP TABLE command of Oracle 9i or earlier versions?
A. DROP TABLE table_name
B. DROP TABLE PURGE table_name
C. PURGE TABLE table_name
D. PURGE TABLE recycle_bin_object

B

C. The command equivalent to the DROP TABLE command of Oracle 9i or earlier is PURGE
TABLE table_name. The PURGE TABLE recycle_bin_object command only purges from the
Recycle Bin. See Chapter 6 for more information.

答案不对
应该是drop table ... purge
purge table ...是从垃圾箱里删除

30.
21. How would you assure that the triggers you need enabled are enabled and the triggers you need disabled are disabled after a Flashback Table recovery? (Choose all that apply.)
A. Make sure that all triggers are enabled before a table is Flashback Table recovered.
B. Make sure that all triggers that need to be disabled are disabled before the Flashback Table command is executed with the ENABLE TRIGGERS option.
C. Manually enable and disable all triggers after the Flashback Table recovery.
D. Make sure that all triggers are disabled before a table is Flashback Table recovered.

B

B, C. The Flashback Table command by default disables all triggers unless the ENABLE TRIGGERS
option is used. If the ENABLE TRIGGERS option is used, all enabled triggers at the time of the Flashback
Table recovery are enabled. All disabled triggers at the time of the Flashback Table recovery
are disabled. The last option is to manually enable and disable all triggers after the Flashback Table
recovery has been performed. See Chapter 6 for more information.

PDF教程10-29
C 说的不准确, 应该是闪回之前先设置好触发器状态, 之后再恢复

31.
22. How can you identify multiple objects dropped with the same name in the Recycle Bin?
A. In the RECYCLEBIN view, the column ORIGINAL_NAME will be unique.
B. In the RECYCLEBIN view, the column OBJECT_NAME will be unique.
C. In the RECYCLEBIN view, the columns ORIGINAL_NAME and ORGINAL_NAME will be different.
D. None of the above.

B?

B. The RECYCLEBIN view OBJECT_NAME column will provide a unique name of a database
object, even if the OBJECT_NAME is the same. See Chapter 6 for more information.

教材6-7

32.
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

A

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.

教材6-14 "You can use this feature to undo changes that have resulted in logical data corruptions"
闪回数据库不能修复物理故障

33.
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

D

D. A Flashback Database recovery can recover a large truncated table or group of tables.

教材6-24

34.
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

B

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.

教材6-15
"When you enable Flashback Database, the new RVWR background process is started."

35.
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.

D

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.

教材6-18
"The flash recovery area is a unified storage location for all recovery-related files and activities in an Oracle database."

36.
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

A?D? 什么意思?

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.

意思是, 从哪儿能看到闪回恢复区的状态

37.
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.

BC

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.

PDF教材9-16
系统参数DB_RECOVERY_FILE_DEST_SIZE可被动态修改

38.
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

A?C?

A, C. The flash recovery area supports both the BACKUP and BACKUP COPY commands, which
perform backup sets and image copies.

应该是backup as backupset, backup as copy吧?

39.
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

D?

C. The dynamic view V$RECOVERY_FILE_DEST displays the space utilization and the amount of
files that make up the flash recovery area.

教材6-27
"You can query V$RECOVERY_FILE_DEST to view information regarding the flash recovery area."

40.
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

D 估计是

D. The DB_FLASHBACK_RETENTION_TARGET parameter determines how much data is available
to recover.

教材6-16

41.
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

C 应该是

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.

教材6-16
"You can specify an upper limit, in minutes, on how far back you want to be able to flash back the database."

42.
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.

ACD

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.

教材6-16

43.
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

ABCD???? 不懂

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.

意思是,能够恢复到的最早的时间

44.
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.

B

B. The V$DATABASE dynamic view has a new column called FLASHBACK_ON, which contains a
value of YES or NO.

教材6-16
"SELECT flashback_on FROM v$database;"

45.
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

D

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.

教材6-26
"Use the V$FLASHBACK_DATABASE_STAT view to monitor the overhead of logging flashback data in the Flashback Database logs. "

46.
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

D? 不知道

A. The default size of a redo log file created in the flash recovery area is 100MB.

好像是的

47.
16. Which initialization parameter will not 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

D

D. The LOG_ARCHIVE_DEST_n is the only initialization parameter that will create or write
archive logs to the flash recovery area.

不存在前3个参数

教材6-18
"When the flash recovery area and archiving are configured, USE_DB_RECOVERY_FILE_DEST is configured for archive log destination 10. "

48.
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

BD 不清楚

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.

就是CD嘛
教材6-18
"The recovery-related files that can be created in the flash recovery area include: archived redo log files, control files, backups created by Recovery Manager (RMAN), flashback logs, and the change tracking file. "

49.
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

ABC ??? 不知道

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.

PDF教材9-17
"Other files such as flashback logs, incremental bitmaps, current control file, and
online redo log files are not backed up."

50.
19. What is responsible for applying the “before” images to the database during a Flashback Database recovery?
A. LGWR
B. SMON
C. DBWR
D. RWVR

C?

D. The RWVR 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.

教材6-15
"Subsequently, when a FLASHBACK DATABASE command is issued, the flashback logs are used to restore to the blocks’ before images, and then redo data is used to roll forward to the desired flashback time."
说的就是RVWR进程的作用

51.
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

C D呢?

C. Resizing of a tablespace or datafiles to a smaller size cannot be undone with Flashback Database
recovery.

教材6-24
D, 小试了一下, 不删除数据文件的情况下貌似也可以恢复, 有待进一步的测试

52.
1. Which underlying database technology is used by Flashback Drop, Flashback Table, and Flashback Versions Query to recover data?
A. Redo logs
B. Rollback segments
C. Undo data
D. Archive logs

C flashback drop?

C. All the Flashback Technologies, with the exception of the Flashback Database, utilize the
undo data to recover objects.

教材6-3
此题有问题, 闪回删除表用的是回收箱(Recycle bin)功能

53.
2. Which of the following statements is true regarding the Recycle Bin? (Choose all that apply.)
A. The Recycle Bin is a physical storage area of flashback dropped objects.
B. The Recycle Bin is a logical container area of flashback dropped objects.
C. The objects in the Recycle Bin are stored in the UNDO tablespace.
D. The objects in the Recycle Bin are stored in the tablespace they were created in.

BD

B, D. The Recycle Bin is a logical container of flashback dropped objects. The objects in the
Recycle Bin are stored in the tablespace they were created in.

是逻辑区域, 在同一个表空间

教材6-5
"The recycle bin itself is a data dictionary table that maintains the relationships between the original names of dropped objects and their system-generated names"

54.
3. What actions does the Flashback Drop process perform?
A. Back up table only
B. Back up table and indexes only
C. Back up table and referential constraints only
D. Back up table and dependent objects

D

D. The Flashback Drop process is responsible for backing up tables and their dependent objects.

教材6-7
"Use the FLASHBACK TABLE ... TO BEFORE DROP command to recover a table and all of its possible dependent objects from the recycle bin."

Limitations and Restrictions on Flashback Drop:
"A table and all of its dependent objects (indexes, LOB segments, nested tables, triggers, constraints and so on) go into the recycle bin together, when you drop the table. Likewise, when you perform Flashback Drop, the objects are generally all retrieved together."
"The recycle bin does not preserve referential constraints on a table (though other constraints will be preserved if possible). If a table had referential constraints before it was dropped (that is, placed in the recycle bin), then re-create any referential constraints after you retrieve the table from the recycle bin with Flashback Drop."

55.
4. Which activity can occur with the Recycle Bin?
A. All indexed-organized tables are protected by the Recycle Bin.
B. System- and dictionary-managed tablespaces are stored in the Recycle Bin.
C. Dependent objects of stored tables—including referential constraints—are stored in the Recycle Bin.
D. Data Manipulation Language (DML) and Data Definition Language (DDL) can be run against objects in the Recycle Bin.
E. None of the above.

C

E. Only non-partitioned index-organized tables are protected by the Recycle Bin. Non-system and
locally managed tablespaces are stored in the Recycle Bin. Referential constraints are not stored in
the Recycle Bin. DML or DDL cannot be performed against objects in the Recycle Bin.

都不行
见上题链接

56.
5. One method of dropping objects and bypassing the Recycle Bin is to perform which command?
A. DROP USER user CASCADE
B. DROP TABLE
C. DROP TABLE INCLUDING CONTENTS
D. DROP USER user

A

A. The command DROP USER user CASCADE drops the user and the database objects without
recording a backup in the Recycle Bin. Objects in the Recycle Bin owned by the user will be
removed from the Recycle Bin.

教材6-11

57.
6. Which command is responsible for removing the objects in multiple users from the Recycle Bin?
A. PURGE RECYCLEBIN
B. PURGE TABLESPACE user
C. PURGE DBA_RECYCLEBIN
D. PURGE TABLES user

B? 忘了

C. The PURGE DBA_RECYCLEBIN command purges the complete Recycle Bin for all users.

教材6-10

58.
7. What is the naming convention of a Recycle Bin object?
A. BIN$globalUID$version
B. BIN$global$UIDversion
C. BIN$globalUIDversion
D. BINglobalUIDversion

A?

A. The naming convention of objects in the Recycle Bin consists of a globalUID and version
number assigned by the database with BIN$ prefixed, and a $ between the globalUID and the
version number. The formatting looks like BIN$globalUID$version.

Naming Convention for Objects in the Recycle Bin

59.
8. What two methods can be used to view the Recycle Bin?
A. Run the SHOW RECYCLEBIN command.
B. Query the view DBA_RECYCLEBIN.
C. Query the view V$RECYCLEBIN.
D. Query the view RECYCLEBIN.

AB

A, D. The SHOW RECYCLEBIN command and querying the RECYCLEBIN view are two methods of
viewing the contents of the Recycle Bin.

教材6-12
D 题意不明, 可能想说的是, 查询recyclebin视图, 包括了user_recyclebin和dba_recyclebin

60.
9. What best describes the space pressure in the Recycle Bin?
A. No free extents in the Recycle Bin, and objects being removed from the Recycle Bin to free up extents for non-Recycle Bin objects.
B. No free extents in a tablespace, and objects being removed from the Recycle Bin to free up extents for non-Recycle Bin objects.
C. No free extents in a tablespace, and objects being removed from the Recycle Bin to free up extents in a tablespace for non-Recycle Bin objects on a first in, first out (FIFO) basis.
D. No free extents in the Recycle Bin tablespace and objects being removed from Recycle Bin tablespace to free up extents for non-Recycle Bin objects on a first in, first out (FIFO) basis.

D

C. The Recycle Bin is not stored in a Recycle Bin tablespace. It is a logical container pointing to
objects in the tablespace where the objects were originally created. Objects are removed from the
Recycle Bin when there is a need for available extents in a non-system tablespace. The objects are
removed on a first in, first out (FIFO) basis.

没看清,"objects being removed from Recycle Bin tablespace"这句错了

61.
10. If a tablespace is configured for AUTO EXTEND, what will occur when there are no free extents and there are objects in the AUTO EXTEND tablespace?
A. The tablespace will autoextend to make more free space and Oracle will not remove Recycle Bin objects associated with the tablespace.
B. The tablespace will not autoextend, and objects in the Recycle Bin will be removed to make space in the tablespace.
C. The tablespace will autoextend to make more free space and Oracle will remove Recycle Bin objects associated with the tablespace.
D. The tablespace will not autoextend, and objects in the Recycle Bin will be compressed to make space in the tablespace.

B

B. A tablespace with AUTO EXTEND enabled will not autoextend to make space for the Recycle
Bin objects. The objects will be removed from the Recycle Bin in the standard first in, first out
(FIFO) basis.

教材6-8

62.
11. Which of the following statements best describes Flashback Versions Query?
A. Flashback Versions Query is a query to perform diagnostics on version changes in row data on rows that existed between the times the query was executed to a determined point-in-time in the past.
B. Flashback Versions Query is a method of querying all version changes on rows that existed between the times the query was executed to a determined point-in-time in the past.
C. Flashback Versions Query is a query to perform diagnostics on table changes in row data on rows that existed between the times the query was executed to a determined point-in-time in the past.
D. Flashback Versions Query is a method of querying all version changes on rows that existed between the times the query was executed to a determined point-in-time in the future.

B

B. Flashback Versions Query is a method of querying all version changes on rows. The rows
must exist from the time the query was executed to a point-in-time in the past. The query will
not display committed data after the query has been executed.

A,C不是诊断
D 不是未来的

PDF教材10-17
"With the Flashback Query feature, you can perform queries on the database as of a certain time
or user-specified system change number (SCN)."

63.
12. What view can be used to query diagnostic information about transactional changes in the database?
A. FLASHBACK_TRANSACTION_QUERY
B. DBA_TRANSACTION_QUERY
C. V$TRANSACTION_QUERY
D. V$FLASHBACK_TRANSACTION_QUERY

D?

A. The view FLASHBACK_TRANSACTION_QUERY is used as a diagnostic tool to identify version
information about transactional changes to the database. This view can be used to view the
DML statements that were executed against a row and in a specific table.

PDF教材10-22
"Flashback Transaction Query is a diagnostic tool you can use to view changes made to the
database at the transaction level."
"You can use the FLASHBACK_TRANSACTION_QUERY view to determine all of the necessary
SQL statements that can be used to undo the changes made by a specific transaction, or during a
specific period of time."

64.
13. What are the methods of performing a Flashback Versions Query? (Choose all that apply.)
A. Flashback Versions Query can be performed by minimum and maximum SCN value.
B. Flashback Versions Query can be performed by minimum and maximum sequence number.
C. Flashback Versions Query can be performed by starting and ending timestamp.
D. Flashback Versions Query can be performed by minimum and maximum undo value.

AC

A, C. The Flashback Versions Query can be performed by either MINVALUE and MAXVALUE SCN
or starting and ending TO_TIMESTAMP value.

PDF教材10-17
"With the Flashback Query feature, you can perform queries on the database as of a certain time
or user-specified system change number (SCN)."

65.
14. Which of the following statements is true regarding the VERSIONS BETWEEN clause?
A. The VERSIONS BETWEEN clause only supports SCN.
B. The VERSIONS BETWEEN clause only supports log sequences.
C. The VERSIONS BETWEEN clause cannot produce versions past modifications to the table structure.
D. The VERSIONS BETWEEN clause can produce versions past Data Definition Language (DDL) changes to an object.

C

C. The VERSIONS BETWEEN clause of the Flashback Versions Query cannot query past table
modifications or DDL changes to a table.

A. 还可以是时间戳
B. 不支持
C. PDF教材10-21
D. 不可以

66.
15. Which pseudocolumn do you use to identify a unique row in a Flashback Versions Query?
A. VERSIONS_XID
B. VERSIONS_OPERATION
C. VERSIONS_ENDTIME
D. VERSION_STARTTIME

A?

A. VERSIONS_XID uniquely identifies a row in the Flashback Versions Query. The other
pseudocolumns can narrow down the selection criteria and may identify multiple rows in
a timeframe or SCN range.

PDF教材10-17
"VERSIONS_XID is a new pseudo-column that returns the transaction identifier of the corresponding version of a row."

好像不对?不是唯一的

67.
16. Which of the following statements are true regarding the VERSIONS BETWEEN clause? (Choose all that apply.)
A. The VERSIONS BETWEEN clause may be used in DML statements.
B. The VERSIONS BETWEEN clause may be used in DDL statements.
C. The VERSIONS BETWEEN clause may be used to query past DDL changes to tables.
D. The VERSIONS BETWEEN clause may not be used to query past DML statements to tables.

AB 好像是

A, B. The VERSIONS BETWEEN clause can be used in DML and DDL statements to identify data.

CD肯定不对
B 大概是说create table as select

68.
17. Which of the following statements is true regarding implementing a Flashback Table recovery?
A. SCN is never needed to perform a Flashback Table recovery.
B. ROW MOVEMENT must be enabled to perform a Flashback Table recovery.
C. Only one table may be recovered to perform a Flashback Table recovery.
D. Flashback Table recovery does not use undo data to perform a Flashback Table recovery.

B

B. The command ALTER TABLE table_name ENABLE ROW MOVEMENT must be enabled to allow
Flashback Table recovery.

PDF教材10-29

69.
18. What happens to enabled triggers on a table after a FLASHBACK TABLE command is performed? (Choose all that apply.)
A. The triggers are disabled by default.
B. The triggers are enabled by default.
C. Disabled triggers remain disabled with the default FLASHBACK TABLE command.
D. All triggers are enabled if the ENABLE TRIGGER clause is used.

ACD

A, C. The default action for the FLASHBACK TABLE command is that the triggers will be disabled.
If you disable the triggers on a table, the triggers will stay disabled after the FLASHBACK
TABLE command as well. Also, if you use the ENABLE TRIGGER clause, all enabled triggers on
the table prior to the Flashback Table operation will be enabled and all disabled triggers will
be disabled.

PDF教材10-29

70.
19. What method can you use to identify a DML operation and the SQL statement that has been performed against a row in a specific table for a schema owner? (Choose all that apply.)
A. Query DBA_TRANSACTION_QUERY for TABLE_NAME, OPERATION, and UNDO_SQL. Limit rows by START_SCN and TABLE_OWNER.
B. Query FLASHBACK_TRANSACTION_QUERY for TABLE_NAME, OPERATION, and UNDO_SQL. Limit rows by START_SCN and TABLE_OWNER.
C. Query FLASHBACK_TRANSACTION_QUERY for TABLE_NAME, OPERATION, and UNDO_SQL. Limit rows by START_TIMESTAMP and TABLE_OWNER.
D. Query DBA_TRANSACTION_QUERY for TABLE_NAME, OPERATION, and UNDO_SQL. Limit rows by START_SCN and TABLE_OWNER.

C?

B, C. The proper method is to query the FLASHBACK_TRANSACTION_QUERY view. The TABLE_
NAME, OPERATION, and UNDO_SQL columns should be queried to display the information about
the transactional information. The transactional information from FLASHBACK_TRANSACTION_
QUERY should then be narrowed down by START_TIMESTAMP or START_SCN. Then the information
can be further narrowed down by TABLE_OWNER. Alternatively, the XID, if known, can be queried
to identify the exact transaction, but that was not an option in this example.

PDF教材10-23

71.
20. How can you protect the amount of time you can query information from the Flashback Transaction Query?
A. Add UNDO GUARANTEE to the UNDO tablespace.
B. Add RETENTION GUARANTEE to the UNDO tablespace.
C. Add RETENTION GUARANTEE to the Recycle Bin logical storage container.
D. Add UNDO GUARANTEE to the Recycle Bin logical storage container.

B

B. Adding RETENTION GUARANTEE to the UNDO tablespace or during database creation to the
UNDO tablespace will protect unexpired undo data in the UNDO tablespace. This is where the
Flashback Transaction Query retrieves information about transaction changes to rows in the
database.

PDF教材10-32

pdf 10-12说:
PURGE TABLESPACE ... This option is useful when a particular user is running low on disk quota for the specified tablespace.
垃圾箱里的东西不是能自动清除吗, 跟磁盘限额有什么关系?

意思是说, 表空间不够了, 也可以手工清除一下释放出空间, 虽然可以自动清除

pdf 10-19:
VERSIONS_STARTSCN or VERSIONS_STARTTIME are NULL if .... before the UNDO_RETENTION time.
只要UNDO有空间，是不是也可以在保留时间之前?

不知道

-fin-