[oracle@localhost tmp]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Jun 24 16:07:03 2020
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup upgrade
ORACLE instance started.
Total System Global Area 754971816 bytes
Fixed Size 9139368 bytes
Variable Size 482344960 bytes
Database Buffers 260046848 bytes
Redo Buffers 3440640 bytes
Database mounted.
Database opened.
SQL> select con_id,name,open_mode from v$pdbs;
CON_ID
----------
NAME
--------------------------------------------------------------------------------
OPEN_MODE
----------
2
PDB$SEED
MIGRATE
3
ORCLPDB1
MOUNTED
CON_ID
----------
NAME
--------------------------------------------------------------------------------
OPEN_MODE
----------
SQL> alter pluggable database ORCLPDB1 open;
alter pluggable database ORCLPDB1 open
*
ERROR at line 1:
ORA-65054: Cannot open a pluggable database in the desired mode.
SQL>