501.Note the output of the following query;

SQL> SELECT flashback_archieve_name, status FROM dba_flashback_archieve; 此处表名有点错误，应该为DBA_FLASHBACK_ARCHIVE

FLASHBACK_ARCHIEVE_NAME STATUS

FLA1

You executed the following command to enable Flashback Data Archive on the EXCHANGB_PATE table:

ALTER TABLE exchange_rate FLASHBACK ARCHIEVE;

What is the outcome of this command?

A. The table uses the default Flashback Data Archive.

B. The Flashback Data Archive Is created In the SYSAUX tablespace.

C. The Flashback Data Archive is created in the same tablespace where the tables are stored.

D. The command generates an error because no flashback Data Archive name is specified and there is

no default Flashback Data Achieve.

Answer: A

答案解析：

实验验证：

1、首先创建一个表空间用于存储闪回数据归档

sys@TEST1107> create tablespace fla_tbs1

  2  datafile '/u01/app/oracle/oradata/test1107/fla_tbs01.dbf' size 10M;

Tablespace created.

2、创建闪回数据归档

sys@TEST1107>  create flashback archive fla1 tablespace fla_tbs1 quota 10M retention 1 year;

Flashback archive created.

3、查询有哪些闪回数据归档以及其状态。

sys@TEST1107> select FLASHBACK_ARCHIVE_NAME,STATUS from DBA_FLASHBACK_ARCHIVE;

FLASHBACK_ARCHIVE_NAME         STATUS

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

FLA1

4、对scott.dept表启用闪回数据归档，报错，因为没有指定默认闪回归档。

sys@TEST1107> alter table scott.dept flashback archive;

alter table scott.dept flashback archive

*

ERROR at line 1:

ORA-55608: Default Flashback Archive does not exist

5、将FLA1指定为默认闪回数据归档。

sys@TEST1107> alter flashback archive FLA1 set default;

Flashback archive altered.

6、查询，此时须注意，status栏位下面的有DEFAULT的状态。

sys@TEST1107> select FLASHBACK_ARCHIVE_NAME,STATUS from DBA_FLASHBACK_ARCHIVE;

FLASHBACK_ARCHIVE_NAME         STATUS

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

FLA1                           DEFAULT

7、对表启用闪回数据归档，成功。

sys@TEST1107> alter table scott.dept flashback archive;

Table altered.

对于题中的显示，FLA1的状态栏位为空值，即没有指定FLA1为默认的闪回数据归档，所以，此题题库给的答案是错的。正确答案为D.

B答案：这里没有说闪回数据归档被创建在哪个表空间，可以根据DBA_FLASHBACK_ARCHIVE_TS;来查询，此处没有提供。