ORA-65086: cannot open/close the pluggable database

一旦pdb执行了unplug，然后想在该cdb中重新使用该pdb，不能直接操作，需要先drop，然后重新plug到该cdb中：

SQL>  show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 TESTCS1                        READ WRITE NO
         4 PDB_PLUG_NOCOPY                MOUNTED
         5 CRM                            READ WRITE NO
         6 ESSDB                          READ WRITE NO
         8 PDB_PLUG_MOVE                  READ WRITE NO
        
QL> alter PLUGGABLE database   PDB_PLUG_NOCOPY  open;
alter PLUGGABLE database   PDB_PLUG_NOCOPY  open
*
ERROR at line 1:
ORA-65086: cannot open/close the pluggable database

SQL>  drop pluggable database PDB_PLUG_NOCOPY;

Pluggable database dropped.

SQL>  show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 TESTCS1                        READ WRITE NO
         5 CRM                            READ WRITE NO
         6 ESSDB                          READ WRITE NO
         8 PDB_PLUG_MOVE                  READ WRITE NO
        
         然后重新plug后使用。