1、查询归档当前信息

SQL> show parameter recovery
NAME                    TYPE    VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest            string
db_recovery_file_dest_size        big integer 0
recovery_parallelism            integer    0

2、查询是否开户归档日志
SQL> archive log list
Database log mode          Archive Mode
Automatic archival          Enabled
Archive destination          /oracle/app/oracle/product/11.2.0/db_1/dbs/arch
Oldest online log sequence    35
Next log sequence to archive  36
Current log sequence          36

  说明：从当前查询是已开始归档模式了，但是规定路径不对要重新修改

3、查询集群参数

SQL> show parameter cluster
NAME                    TYPE    VALUE
------------------------------------ ----------- ------------------------------
cluster_database            boolean    TRUE
cluster_database_instances        integer    2
cluster_interconnects            string

4、关闭另外一个节点数据库

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

5、在当前正常节点修改集群为单节点模式
SQL> alter system set cluster_database=false scope=spfile;
System altered.

6、配置闪回大小

SQL> alter system set db_recovery_file_dest_size=2G scope=both;
System altered.

7、配置归档日志路径，配置在DG中

SQL> alter system set db_recovery_file_dest='+DGRECOVERY'scope=both;
System altered.

8、关闭当前节点数据库

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

9.把当前节点数据库启动到mount状态中修改归档

SQL> startup mount
ORACLE instance started.
Total System Global Area  784998400 bytes
Fixed Size            2257352 bytes
Variable Size          331353656 bytes
Database Buffers      448790528 bytes
Redo Buffers            2596864 bytes
Database mounted.

10.查询当前数据库是处于什么状态

SQL> select status from v$instance
  2  ;
STATUS
------------
MOUNTED

11.修改数据库归档

SQL> alter database archivelog;
Database altered.

12.恢复数据库双节点实例

SQL> alter system set cluster_database=true scope=spfile;
System altered.

13.打开数据库

SQL> alter database open;
Database altered.

14.查询当前数据库状态

SQL> select status from v$instance;
STATUS
------------
OPEN

15、查询数据库集群状态

123456 SQL> show parameter cluster
NAME                    TYPE    VALUE
------------------------------------ ----------- ------------------------------
cluster_database            boolean    TRUE
cluster_database_instances        integer    2
cluster_interconnects            string

16、再启动另外一个节点
        startup

17、切换归档日志，判断是否切换成功
SQL> alter system switch logfile;
System altered.

18、查询归档中数据