How to open pluggable database (PDBs) in Oracle 19 C

How to open pluggable database (PDBs) in Oracle 19 C

First need to log in and check the PDB status

C:\WINDOWS\system32>sqlplus /nolog
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Mar 25 21:53:59 2020
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle.  All rights reserved.
SQL> conn sys/orcl as sysdba
Connected.
SQL> show pdbs
    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 ONTOOR                         READ WRITE NO
         4 APEX_5                         MOUNTED
         5 APEX_19_2                      READ WRITE NO
         6 APEX_18_2                      READ WRITE NO
SQL>

So the open mode is mounted for PDB APEX_5. Lets open the PDB.

SQL> alter pluggable database APEX_5 open;
Pluggable database altered.
SQL> show pdbs
    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 ONTOOR                         READ WRITE NO
         4 APEX_5                         READ WRITE NO
         5 APEX_19_2                      READ WRITE NO
         6 APEX_18_2                      READ WRITE NO
SQL>

After altering the Pluggable database OPEN and mode is turned to READ and WRITE.

To open all the available PDBs automatically we can create database STARTUP trigger.

CREATE OR REPLACE TRIGGER open_all_pdbs
   AFTER STARTUP
   ON DATABASE
BEGIN
   EXECUTE IMMEDIATE 'alter pluggable database all open';
END open_all_pdbs;

How to Close PDBs?

ALTER PLUGGABLE DATABASE apex_5 CLOSE;