正常oracle12c rac容器数据库克隆pdb的流程如下：
1.alter system set db_Create_file_dest=’+NEWBACKUP’ scope=memory;
2.alter pluggable database mala close immediate;
3.alter pluggable database mala open read only;
4.create pluggable database mala_test FROM mala;
5.alter pluggable database mala close immediate;
6.alter pluggable database mala open;
再执行第二步结束pdb的操作时hung住了，通知应用组结束所有应用后，执行如下命令kill掉所有会话之后再次执行第二步。
alter session set container=mala;
select ‘alter system kill session ‘’’||sid ||’,’||serial#||’’’;’
结果还是一样，执行不成功。
所以使用如下abort命令强制结束
alter pluggable database mala close abort;
这下出问题了，执行alter pluggable database mala open read only;报如下错误
SQL> alter database open read only;
alter database open read only
*
ERROR at line 1:
ORA-00704: bootstrap process failure
ORA-01187: cannot read from file because it failed verification tests
ORA-01110: data file 152: ‘+MYDBDATA/MYDB/BD26B68506887426E0532145020A87B0/DATAFILE/system.675.1066819757’
执行介质恢复
SQL> recover datafile 152;
ORA-00279: change 315649394791 generated at 09/04/2023 20:30:25 needed for thread 1
ORA-00289: suggestion : +MYBDATA/CHECDB/ARCHIVELOG/2023_09_04/thread_1_seq_125837.1596.1146688369
ORA-00280: change 315649394791 for thread 1 is in sequence #125837
Specify log: {
AUTO
ORA-00279: change 315649398313 generated at 09/04/2023 20:32:49 needed for thread 1
ORA-00289: suggestion : +MYBDATA/MYDB/ARCHIVELOG/2023_09_04/thread_1_seq_125838.1717.1146688809
ORA-00280: change 315649398313 for thread 1 is in sequence #125838
Log applied.
Media recovery complete.
把遇到问题的文件都执行了介质恢复之后，数据库终于可以打开了，
在两个节点分别执行以下：
alter pluggable database mala open read only;
然后在其中一个节点执行reate pluggable database mala_test FROM mala;创建克隆PDB即可。
克隆180G的数据还是挺快的，不到20分钟就执行完成了。
