查看进程的活动状况—v$managed_standby
select process,client_process,sequence#,status from v$managed_standby;
PROCESS列显示进程信息
CLIENT_PROCESS列显示对应的主数据库中的进程
SEQUENCE#列显示归档redo的序列号
STATUS列显示的进程状态
确认redo应用进度—v$archive_dest_status
select dest_name,archived_thread#,archived_seq#,applied_thread#,recovery_mode, applied_seq#,db_unique_name from v$archive_dest_status where status=’VALID’;
检查归档文件路径及创建信息—v$archived_log
select name,creator,sequence#,applied,completion_time from v$archived_log;
select dest_id,max(sequence#) from v$archived_log group by dest_id;
查询归档历史—v$log_history
查询当前数据的基本信息—v$database信息
Data guard事件—v$dataguard_status
select message from v$dataguard_status;

1)Verify it is possible to perform a switchover on the primary database.
SELECT SWITCHOVER_STATUS FROM V$DATABASE;–TO STANDBY/SESSIONS ACTIVE
2)Prepare the current primary database for the switchover
ALTER DATABASE PREPARE TO SWITCHOVER TO LOGICAL STANDBY;–PREPARING SWITCHOVER
ALTER DATABASE PREPARE TO SWITCHOVER CANCEL;–cancel（终止操作）
3)Prepare the target logical standby database for the switchover
ALTER DATABASE PREPARE TO SWITCHOVER TO PRIMARY;
–PREPARING DICTIONARY–>PREPARING SWITCHOVER
ALTER DATABASE PREPARE TO SWITCHOVER CANCEL;–cancel（终止操作）
4)Ensure the current primary database is ready for the future primary
database’s redo stream
SELECT SWITCHOVER_STATUS FROM V$DATABASE;–TO LOGICAL STANDBY
5)Switch the primary database to the logical standby database role
ALTER DATABASE COMMIT TO SWITCHOVER TO LOGICAL STANDBY;
6)Ensure all available redo has been applied to the target logical standby
database that is about to become the new primary database
SELECT SWITCHOVER_STATUS FROM V$DATABASE;–TO PRIMARY
7)Switch the target logical standby database to the primary database role
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
8)Start SQL Apply on the new logical standby database
ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;

1、Create a Physical Standby Database
11g data guard（PHYSICAL STANDBY）配置
2、Stop Redo Apply on the Physical Standby Database
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
3、Prepare the Primary Database to Support a Logical Standby Database
1）Prepare the Primary Database for Role Transitions

*.log_archive_dest_1='LOCATION=/u01/archive valid_for=(online_logfiles,all_roles) db_unique_name=first'
*.log_archive_dest_3='LOCATION=/u01/archive/standby VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=first'
*.log_archive_dest_state_3='enable'
--其他不修改

2）Build a Dictionary in the Redo Data
EXECUTE DBMS_LOGSTDBY.BUILD;
4、Transition to a Logical Standby Database
1）Convert to a Logical Standby Database
ALTER DATABASE RECOVER TO LOGICAL STANDBY db_name;
Note：
(1)如果数据库是open状态，需要重启，然后置于mount状态
(2)取消使用：RECOVER MANAGED STANDBY DATABASE CANCEL;
(3)如果执行到一半，然后取消，导致原物理库损坏（不能同步），从主库中重新生成备库的control file，然后启动物理库同步
2）Adjust Initialization Parameters for the Logical Standby Database

SHUTDOWN;
STARTUP MOUNT;
alter system set log_archive_dest_3='LOCATION=/u01/archive/standby VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=second';
alter system set log_archive_dest_1='LOCATION=/u01/archive valid_for=(online_logfiles,all_roles) db_unique_name=second';
alter system set LOG_ARCHIVE_DEST_STATE_3='ENABLE';

5、Open the Logical Standby Database
ALTER DATABASE OPEN RESETLOGS;
–开启实时应用
ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;
–开启应用
ALTER DATABASE START LOGICAL STANDBY APPLY;
–关闭应用
ALTER DATABASE STOP LOGICAL STANDBY APPLY;

Converting a Physical Standby Database into a Snapshot Standby Database

shutdown immedaite
startup mount
ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;
alter database open;

Converting a Snapshot Standby Database into a Physical Standby Database

shutdown immedaite
startup mount
ALTER DATABASE CONVERT TO PHYSICAL STANDBY;
alter database open;--如果出现ORA-01507: database not mounted，重启数据库
alter database recover managed standby database disconnect from session;
alter database recover managed standby database using current logfile disconnect from session;