3. flashback database 3.1 turn on flashback database 3.1.1 configure a flash recovery area of 4gb 3.1.2 put your flash recovery area in /home/oracle/flash (you may have to create this diretory) 3.2 leave your databases open for review. 首
3. flashback database 3.1 turn on flashback database 3.1.1 configure a flash recovery area of 4gb 3.1.2 put your flash recovery area in /home/oracle/flash (you may have to create this diretory) 3.2 leave your databases open for review.首先创建一个路径，然后配置闪回去大小和位置，mount状态下flashback为on，最后打开数据库。
[oracle@ocm1 ~]$ mkdir /home/oracle/flash[oracle@ocm1 ~]$ sqlplus /as sysdba
sql*plus: release 10.2.0.1.0 - production on fri mar 21 14:13:55 2014
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connected to:oracle database 10g enterprise edition release 10.2.0.1.0 - productionwith the partitioning, olap and data mining options
sql> show parameter db_recovery_file_dest
name type value------------------------------------ ----------- ------------------------------db_recovery_file_dest stringdb_recovery_file_dest_size big integer 0
sql> alter system set db_recovery_file_dest_size=4g scope=spfile;
system altered.
sql> alter system set db_recovery_file_dest='/home/oracle/flash' scope=spfile;
system altered.
sql> shutdown immediatedatabase closed.database dismounted.oracle instance shut down.sql> startup mount;oracle instance started.
total system global area 524288000 bytesfixed size 1220360 bytesvariable size 176161016 bytesdatabase buffers 343932928 bytesredo buffers 2973696 bytesdatabase mounted.sql> alter database flashback on;
database altered.
sql> alter database open;
database altered.
sql> select flashback_on from v$database;
flashback_on------------------yes
sql>
sql> show parameter recovery
name type value------------------------------------ ----------- ------------------------------db_recovery_file_dest string /home/oracle/flashdb_recovery_file_dest_size big integer 4grecovery_parallelism integer 0