11R2-DataGuard Scenarios.主备库的闪回

前言：在11R2中的DG中有8种场景，Using Flashback Database After Issuing an Open Resetlogs Statement是第三个场景，大体为在某种操作完成后，主库可闪回之前的某一时间点，而备库也可同样闪回。
13.3 Using Flashback Database After Issuing an Open Resetlogs Statement
前言：由于某种需求，需要将主库和备库都闪回之前的某一个时间点，闪回后，数据库需要open resetlogs打开，而此时，备库也需要闪回，否则就得重新搭建DG。
13.3.1 Flashing Back a Physical Standby Database to a Specific Point-in-Time
实验环境：
 主库+物理备库。开启主备库闪回，随后将主备库都闪回到某一时间点（主库：dong_pri  物理备库：mm_stb）
step 0：开启主备库闪回
step 1：闪回主库
主库：
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
    1596972
SQL> alter system switch logfile;
System altered.
SQL> create table t_after as select * from dba_objects;
Table created.
SQL> alter system switch logfile;
System altered.
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
    1597219
SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     107
Next log sequence to archive   109
Current log sequence           109
物理备库：
SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     107
Next log sequence to archive   0
Current log sequence           109
SQL> select current_scn from v$database;
CURRENT_SCN
-----------
    1597214
开始闪回主库：
SQL> shutdown immediate
SQL> startup mount
SQL> FLASHBACK STANDBY DATABASE TO SCN 1596972;
Flashback complete.
SQL> alter database open resetlogs;
Database altered.
SQL> select count(*) from t_after;
select count(*) from t_after
                     *
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     1
Next log sequence to archive   1
Current log sequence           3
SQL>  select current_scn from v$database;
CURRENT_SCN
-----------
    1597135
step 2：闪回物理备库
SQL> shutdown immediate
SQL> startup mount
SQL> flashback database to scn 1594248;
Flashback complete.
step 3：测试
主库：
SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     2
Next log sequence to archive   4
Current log sequence           4
SQL> alter system switch logfile;
System altered.
物理备库：
SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     3
Next log sequence to archive   0
Current log sequence           107
SQL> archive log list
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/diag/rdbms/dong/
Oldest online log sequence     3
Next log sequence to archive   0
Current log sequence           5
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE  USING CURRENT LOGFILE DISCONNECT;

Database altered.

13.3.2 Flashing Back a Logical Standby Database to a Specific Point-in-Time
实验环境：
 主库+逻辑备库。开启主备库闪回，随后将主备库都闪回到某一时间点（主库：dong_pri  物理备库：mm_stb2）。对于逻辑备库闪回和物理备库闪回其实没啥区别。主要注意步骤不太相同即可。
step 0：开启主备库闪回
step 1：闪回主库
 步骤与上一个实验一样。
step 2：闪回备库
SQL> create table logical_after as select * from dba_objects;
Table created.
SQL> shutdown immediate
SQL> startup mount
SQL> FLASHBACK DATABASE TO SCN 1613195;
Flashback complete.
SQL> alter database open resetlogs;
SQL> SELECT resetlogs_id FROM V$DATABASE_INCARNATION WHERE status = 'CURRENT';
RESETLOGS_ID
------------
   836147774
SQL> SELECT * FROM DBA_LOGSTDBY_LOG WHERE resetlogs_id = 836147774;
no rows selected
SQL> ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;
Database altered.

 

 

 

 

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