Examine these queries and their output: 

SQL> select log mode from vSdatabase;

LOG MODE

---------------------------

ARCHIVELOG

SQL> select property name， property value2 

from database properties where property name like UNDO%';

PROPERTY NAME              PROPERTY VALUE

---------------------------------------------------

LOCAL UNDO ENABLED FALSE

SQL>select p.name, f.filef, t.name

from vScontainers p, vSdatafile f, vStablespace t

  where p.con id=f.con id

 and p.com id=t.con id

 and t,ts#=f.ts#

 order by 1,2;

NAME              FILE            NAME

CDBSROOT       1              SYSTEM

PDB1                 24             SYSTEM

PDB2                  16            SYSTEM

After a system crash, an instance restart and an attempted opening of the PDBs result in:

SQl> startup quiet

ORACIE instance started.

Database mounted.

Database opened.

SQL> alter plugqable database all open;alter pluqgable database all open

ERROR at line 1:ORA-01157: cannot identify/lock data file 24 - see DBWR trace fileORA-01110:data file 24:

'/u01/oradata/V122CDB1/516000726D464D04E054000C29704164/datafile/o1 mf system dmj30kld .dbf'