1.版本号。

SQL> select * from v$version;

BANNER
----------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production

TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

2.查看是否设置了闪回

SQL> select flashback_on ,name from v$database;

FLASHBACK_ON       NAME
------------------ ---------
NO                 ORCL

3.设置闪回功能

 要在mount 状态

shutdown immediate

startup mount

alter database flashback on;

alter database open;

4.查看是否设置成功

SQL> select flashback_on,name from v$database;

FLASHBACK_ON       NAME
------------------ ---------
YES                ORCL