12c数据库重启后自动启动pdb

　　由于最近管理12c数据库，创建了9个新的pdb。相对于以前11g版本每天一个一个的环境检查，方便了很多。

　　但是因为一次意外宕机，数据库重启。虽然数据库重启，但是管理的pdb确不能自动重启，所以需要手动设置。

下面来演示一下手动修改过程：

[oracle@test ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Thu Feb 14 21:12:37 2019

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> show pdbs;

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 4 TESTPDB			  READ WRITE NO
SQL> alter pluggable database all save state;

Pluggable database altered.

SQL> shutdown immeidate;
重启数据库
SQL> startup;
ORACLE instance started.

Total System Global Area  977272832 bytes
Fixed Size		    8799896 bytes
Variable Size		  645925224 bytes
Database Buffers	  318767104 bytes
Redo Buffers		    3780608 bytes
Database mounted.
Database opened.
SQL> show pdbs;

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 4 TESTPDB			  READ WRITE NO

　　重启数据库，testpdb自动重启，保持当前的状态。

　　alter pluggable database all save state;