Switchover 角色切换

(一) 主、备角色互换

(01). 主库操作:

1) 查看状态

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;

SWITCHOVER_STATUS

TO STANDBY

2) 切换状态到standby

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;

SQL> SHUTDOWN IMMEDIATE;

3) 置于Open Read Real Time恢复状态

SQL> startup mount;

ORACLE instance started.

Total System Global Area 1660944384 bytes

Fixed Size 8793448 bytes

Variable Size 989856408 bytes

Database Buffers 654311424 bytes

Redo Buffers 7983104 bytes

Database mounted.

SQL> ALTER DATABASE OPEN;

Database altered.

SQL> show pdbs;

CON_ID CON_NAME OPEN MODE RESTRICTED

2 PDB$SEED READ ONLY NO

3 NAILPDB1 MOUNTED

4 PDB2 MOUNTED

5 PDB3 MOUNTED

SQL> alter pluggable database all open;

Pluggable database altered.

SQL> show pdbs;

CON_ID CON_NAME OPEN MODE RESTRICTED

2 PDB$SEED READ ONLY NO

3 NAILPDB1 READ ONLY NO

4 PDB2 READ ONLY NO

5 PDB3 READ ONLY NO

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

Database altered.

SQL> select open_mode,database_role,protection_mode,protection_level from v$database;

OPEN_MODE DATABASE_ROLE PROTECTION_MODE PROTECTION_LEVEL

READ ONLY WITH APPLY PHYSICAL STANDBY MAXIMUM AVAILABILITY MAXIMUM AVAILABILITY

(02). 备库操作:

以下在备库操作(Backup)

01). 查看状态

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;

SWITCHOVER_STATUS

TO PRIMARY

02). 备库切到Primary角色

SQL>ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;

数据库已更改。

03). 打开数据库

SQL>ALTER DATABASE OPEN;

数据库已更改。

SQL> select open_mode from v$database;

OPEN_MODE

READ WRITE

SQL> select open_mode,database_role,protection_mode,protection_level from v$database;

OPEN_MODE DATABASE_ROLE PROTECTION_MODE PROTECTION_LEVEL

READ WRITE PRIMARY MAXIMUM AVAILABILITY MAXIMUM AVAILABILITY

SQL> show pdbs;

CON_ID CON_NAME OPEN MODE RESTRICTED

2 PDB$SEED READ ONLY NO

3 NAILPDB1 MOUNTED

4 PDB2 MOUNTED

5 PDB3 MOUNTED

SQL> alter pluggable database all open;

Pluggable database altered.

SQL>

SQL> show pdbs;

CON_ID CON_NAME OPEN MODE RESTRICTED

2 PDB$SEED READ ONLY NO

3 NAILPDB1 READ WRITE NO

4 PDB2 READ WRITE NO

5 PDB3 READ WRITE NO

SQL>

根据上述日志可以看出，切换命令是在CDB中执行的，且所有PDB也会被切换。