开启flashback 报ORA-02097 和 ORA-16019错误

开启回闪进行测试：

确认数据库是否打开了flashback的方法：
SQL> select name,log_mode,flashback_on from v$database;
NAME      LOG_MODE     FLASHBACK_ON
--------- ------------ ------------------
ORA11G     ARCHIVELOG   NO           --> flashback未打开

确定flashback的存储路径
SQL> show parameter recovery
NAME                               TYPE        VALUE
-----------------------------     ----------- ------------------------------
db_recovery_file_dest         string
db_recovery_file_dest_size  big integer   0

SQL>alter system set db_recovery_file_dest_size=20G scope=both;
System altered.
SQL> show parameter recovery
NAME                               TYPE           VALUE
-------------------------------  -----------     ------------------------------
db_recovery_file_dest         string
db_recovery_file_dest_size  big integer    20G
recovery_parallelism           integer          0

SQL> alter system set db_recovery_file_dest='/home/oracle/flashback' scope=both;
alter system set db_recovery_file_dest='/home/oracle/flashback' scope=both
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-16019: cannot use db_recovery_file_dest with LOG_ARCHIVE_DEST or LOG_ARCHIVE_DUPLEX_DEST

查看 LOG_ARCHIVE_DES 发现
SQL>show parameter LOG_ARCHIVE_DES
log_archive_dest                     string      /u01/app/oracle/arch
已经设置了归档路径，需要清空

SQL>alter system set log_archive_dest='' scope=both;

之后再执行

alter system set db_recovery_file_dest='/home/oracle/flashback' scope=both;

成功。

在打开数据库的flashback必须要mount状态下方可以，于是：
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup mount;
ORACLE instance started.
Database mounted.

SQL> alter database flashback on;
Database altered.

SQL> alter database open;
Database altered.

SQL> select name,log_mode,flashback_on from v$database;
NAME      LOG_MODE      FLASHBACK_ON
---------   ------------------  ------------
ORA11G   ARCHIVELOG   YES