OCP-1Z0-053-V12.02-678题

678.Which are the two prerequisites before setting up Flashback Data Archive? (Choose two.)
A.Flash recovery area must be defined
B.Undo retention guarantee must be enabled.
C.Database must be running in archivelog mode.
D.Automatic undo management must be enabled.
E.The tablespace in which the Flashback Data
Archive is created must have automatic segment space
Management (ASSM).
Answer: DE
答案解析：
闪回数据归档参考：/article/1629039.html
A,错误，闪回数据归档跟FRA区没有关系，闪回归档的数据是保存在闪回数据表空间的数据文件里。
B,错误，参考/article/1629038.html，闪回数据归档和undo数据没关系。
C,错误，在非归档模式下也能创建闪回数据归档。

sys@TEST0924> archive log list

Database log mode No Archive Mode

Automatic archival Disabled

Archive destination USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence 16

Current log sequence 20

sys@TEST0924> create flashback archive fla1 tablespace users quota 10M retention 1 year;

Flashback archive created.

D,正确，必须是自动还原管理

自动管理下能创建成功，切换到手动管理后，创建失败。

sys@TEST0924> show parameter undo

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

undo_management string AUTO

undo_retention integer 900

undo_tablespace string UNDOTBS1

sys@TEST0924> create flashback archive fla1 tablespace users quota 10M retention 1 year;

Flashback archive created.

sys@TEST0924> alter system set undo_management=manual scope=spfile;

System altered.

sys@TEST0924> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

sys@TEST0924> startup

ORACLE instance started.

Total System Global Area 3340451840 bytes

Fixed Size 2232960 bytes

Variable Size 3204451712 bytes

Database Buffers 117440512 bytes

Redo Buffers 16326656 bytes

Database mounted.

Database opened.

sys@TEST0924> show parameter undo

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

undo_management string MANUAL

undo_retention integer 900

undo_tablespace string UNDOTBS1

sys@TEST0924> create flashback archive fla2 tablespace users quota 10M retention 1 year;

create flashback archive fla2 tablespace users quota 10M retention 1 year

*

ERROR at line 1:

ORA-55628: Flashback Archive supports Oracle 11g or higher

E，正确。TESTUNDOTBS 为手动管理的，在此上面创建闪回数据归档，报错。所以必须在ASSM表空间下使用

sys@TEST0924> select tablespace_name,segment_space_management from dba_tablespaces;

TABLESPACE_NAME SEGMEN

------------------------------ ------

SYSTEM MANUAL

SYSAUX AUTO

UNDOTBS1 MANUAL

TEMP MANUAL

USERS AUTO

EXAMPLE AUTO

TESTTBS AUTO

TESTUNDOTBS MANUAL

8 rows selected.

sys@TEST0924> create flashback archive fla2 tablespace users quota 10M retention 1 year

2

sys@TEST0924> create flashback archive fla2 tablespace TESTUNDOTBS quota 10M retention 1 year;

create flashback archive fla2 tablespace TESTUNDOTBS quota 10M retention 1 year

*

ERROR at line 1:

ORA-55627: Flashback Archive tablespace must be ASSM tablespace