Oracle PDB save state

最近在一次高可用测试中，发现重启后PDB没有打开。原因是启动时，PDB默认处于关闭状态，必须打开PDB，然后保存状态。

以下是在示例RAC环境下的实验。因为是标准的RAC环境，因此在系统表中的状态为OPEN，表示数据库重启后，PDB会自动打开：

col con_name for a20
col instance_name for a20
select con_name, instance_name, state from dba_pdb_saved_states;

CON_NAME             INSTANCE_NAME        STATE
-------------------- -------------------- --------------
ORCLPDB1             DBRAC1               OPEN
ORCLPDB1             DBRAC2               OPEN

以下是在关闭和打开数据库时，save state的实验：

SQL> alter pluggable database orclpdb1 close instances=all;

Pluggable database altered.

SQL> select con_name, instance_name, state from dba_pdb_saved_states;

CON_NAME             INSTANCE_NAME        STATE
-------------------- -------------------- --------------
ORCLPDB1             DBRAC1               OPEN
ORCLPDB1             DBRAC2               OPEN

SQL> alter pluggable database orclpdb1 save state instances=all;

Pluggable database altered.

SQL> select con_name, instance_name, state from dba_pdb_saved_states;

no rows selected

SQL> alter pluggable database orclpdb1 open instances=all;

Pluggable database altered.

SQL> select con_name, instance_name, state from dba_pdb_saved_states;

no rows selected

SQL> alter pluggable database orclpdb1 save state instances=all;

Pluggable database altered.

SQL> select con_name, instance_name, state from dba_pdb_saved_states;

CON_NAME             INSTANCE_NAME        STATE
-------------------- -------------------- --------------
ORCLPDB1             DBRAC1               OPEN
ORCLPDB1             DBRAC2               OPEN

学习到两点：

1. 在DBA_PDB_SAVED_STATES检查save state的设置
2. 在RAC环境下，可以用instances=all指定所有实例