Oracle 11.2.0.4.0 Dataguard部署和日常维护(7) - Dataguard Flashback篇

1. 设置备库的闪回目录

show parameter db_recovery_file;

NAME                     　　　　　　　　TYPE                   　　　　　　VALUE
------------------------------------ --------------------------------- -------------------------------------------
db_recovery_file_dest             　　 string                   　　　　 /u01/app/oracle/fast_recovery_area
db_recovery_file_dest_size         　　big integer                      4G

2. 开启备库的闪回功能

select flashback_on from v$database;

FLASHBACK_ON
------------------------------------------------------
NO

alter database flashback on;

alter database flashback on
*
ERROR at line 1:
ORA-01153: an incompatible media recovery is active

alter database recover managed standby database cancel;
alter database flashback on;
select flashback_on from v$database;

FLASHBACK_ON
------------------------------------------------------
YES

alter database recover managed standby database using current logfile disconnect from session;

3. 检查主备库同步状态

• on primary

select ads.dest_id,max(sequence#) "Current Sequence",
           max(log_sequence) "Last Archived"
       from v$archived_log al, v$archive_dest ad, v$archive_dest_status ads
       where ad.dest_id=al.dest_id
       and al.dest_id=ads.dest_id
       and al.resetlogs_change#=(select max(resetlogs_change#) from v$archived_log )
       group by ads.dest_id;

   DEST_ID Current Sequence Last Archived
---------- ---------------- -------------
     1         79           79
     2         79           80

• on standby

select al.thrd "Thread", almax "Last Seq Received", lhmax "Last Seq Applied"
      from (select thread# thrd, max(sequence#) almax
          from v$archived_log
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) al,
         (select thread# thrd, max(sequence#) lhmax
          from v$log_history
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) lh
     where al.thrd = lh.thrd;

    Thread Last Seq Received Last Seq Applied
---------- ----------------- ----------------
     1          79           79

4. 取消备库的恢复进程

select process,status from v$managed_standby;

PROCESS             STATUS
------------------- ------------------------------------
ARCH                CLOSING
ARCH                CLOSING
ARCH                CONNECTED
ARCH                CLOSING
RFS                 IDLE
RFS                 IDLE
RFS                 IDLE
MRP0                APPLYING_LOG

alter database recover managed standby database cancel;

select process,status from v$managed_standby;

PROCESS             STATUS
------------------- ------------------------------------
ARCH                CLOSING
ARCH                CLOSING
ARCH                CONNECTED
ARCH                CLOSING
RFS                 IDLE
RFS                 IDLE
RFS                 IDLE

5. 创建备库的还原点

create restore point before_open_standby guarantee flashback database;
select name from v$restore_point;

NAME
--------------------------------------------------
BEFORE_OPEN_STANDBY

6. 在主库归档日志

alter system archive log current;

7. 确认备库已经归档了最新的日志

select al.thrd "Thread", almax "Last Seq Received", lhmax "Last Seq Applied"
      from (select thread# thrd, max(sequence#) almax
          from v$archived_log
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) al,
         (select thread# thrd, max(sequence#) lhmax
          from v$log_history
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) lh
     where al.thrd = lh.thrd;

    Thread Last Seq Received Last Seq Applied
---------- ----------------- ----------------
     1          80           79

8. 延迟指向被激活的备库的日志归档目的地

show parameter log_archive_dest_state_2;

NAME                     　　　　　　　 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
log_archive_dest_state_2         　　 string                             ENABLE

alter system set log_archive_dest_state_2='DEFER';

show parameter log_archive_dest_state_2;

NAME                                  TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
log_archive_dest_state_2              string                            DEFER

9. 激活备库

alter database activate standby database;
alter database open;
select open_mode,database_role from v$database;

OPEN_MODE                             　　　　　　　　　　　　　　DATABASE_ROLE
------------------------------------------------------------ ------------------------------------------------
READ WRITE                             　　　　　　　　　　　　　 PRIMARY

10. 向备库写入测试数据

begin
for i in 1..10000 loop
insert into test10 values (i,'shall');
end loop;
commit;
end;
 /

PL/SQL procedure successfully completed.

select count(*) from test10;

  COUNT(*)
----------
     10000

11. 将备库闪回至还原点

shutdown immediate;
startup mount;
flashback database to restore point before_open_standby;
alter database convert to physical standby;
shutdown immediate;
startup mount;
alter database recover managed standby database using current logfile disconnect from session;

12. 重新启用到备库的日志归档目的地

alter system set log_archive_dest_state_2='ENABLE';
show parameter log_archive_dest_state_2;

NAME                     　　　　　　　　TYPE                   　　　　　　VALUE
------------------------------------ --------------------------------- ------------------------------
log_archive_dest_state_2         　　　string                   　　　　  ENABLE

13. 测试数据同步是否正常

•  on primary

alter system archive log current;
alter system archive log current;

select ads.dest_id,max(sequence#) "Current Sequence",
           max(log_sequence) "Last Archived"
       from v$archived_log al, v$archive_dest ad, v$archive_dest_status ads
       where ad.dest_id=al.dest_id
       and al.dest_id=ads.dest_id
       and al.resetlogs_change#=(select max(resetlogs_change#) from v$archived_log )
       group by ads.dest_id;

  DEST_ID Current Sequence Last Archived
---------- ---------------- -------------
     1         83           83
     2         83           84

• on standby

select al.thrd "Thread", almax "Last Seq Received", lhmax "Last Seq Applied"
      from (select thread# thrd, max(sequence#) almax
          from v$archived_log
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) al,
         (select thread# thrd, max(sequence#) lhmax
          from v$log_history
          where resetlogs_change#=(select resetlogs_change# from v$database)
          group by thread#) lh
     where al.thrd = lh.thrd;

    Thread Last Seq Received Last Seq Applied
---------- ----------------- ----------------
     1          83           83

14. 清理闪回点

select name from v$restore_point;

NAME
--------------------------------------------------
BEFORE_OPEN_STANDBY

drop restore point BEFORE_OPEN_STANDBY;