oracle11G闪回flashback - 数据库编程

闪回数据库：

如果数据库出现逻辑错误，无法采用闪回表的方式进行恢

复，或者数据库的结构发生了改变，可以通过闪回数据库的

方式把整个数据库回退到出错前的时间点上。步骤：

1，配置数据库为归档模式

2，配置闪回恢复区

3，配置闪回保留时间

4，启用数据库闪回 alter database flashback on;

5，进行闪回数据库

flashback database to timestamp |scn
?

SQL> show user
USER is "SYS"
SQL> archive log list;--查看是否是归档模式
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u01/app/oracle/archive/archive02/
Oldest online log sequence 362
Next log sequence to archive 365
Current log sequence 365
SQL> alter system set log_archive_start = false scope =spfile;--设置为不是自动归档（在9i后失效了，归档模式就是自动的）

System altered.

SQL> shutdown immediate--关闭数据库
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount--打开数据库到mount状态
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.

Total System Global Area 400846848 bytes
Fixed Size 2213776 bytes
Variable Size 276826224 bytes
Database Buffers 117440512 bytes
Redo Buffers 4366336 bytes
Database mounted.
SQL> alter database noarchivelog--修改为非归档模式
2 ;

Database altered.

SQL> alter database open--打开数据库
2 ;
------------------------------------前面是修改数据库为非归档模式------------------ Database altered.

SQL> archive log list;--查看是否归档
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /u01/app/oracle/archive/archive02/
Oldest online log sequence 362
Current log sequence 365
SQL> clear
SQL> !clear

SQL> archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /u01/app/oracle/archive/archive02/
Oldest online log sequence 362
Current log sequence 365
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.

Database altered.

SQL> alter database open;

Database altered.

SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u01/app/oracle/archive/archive02/--归档区，默认是在闪回区
Oldest online log sequence 362
Next log sequence to archive 365
Current log sequence 365
SQL> show parameter db_rec

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /u01/app/oracle/flash_recovery
--闪回区配置 _area
db_recovery_file_dest_size big integer 3882M
db_recycle_cache_size big integer 0
SQL> show parameter db_flashback_retent

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_flashback_retention_target integer 1440--闪回保留时间默认是24小时，也就是1440分钟
SQL> !ls /u01/app/oracle/flash_recovery_area
jiagulun JIAGULUN——里面是空的

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.

Total System Global Area 400846848 bytes
Fixed Size 2213776 bytes
Variable Size 276826224 bytes
Database Buffers 117440512 bytes
Redo Buffers 4366336 bytes
Database

oracle11G闪回flashback(七)