Auto start pluggable databases in oracle 12c

Oracle Database 12c does not have mechanism to automatically open pluggable databases i.e. container database starts, but all pluggable database stay in the mount state, not open. To run automatically, we can use a trigger.

CREATE or REPLACE trigger OPEN_PDS After Startup on Database BEGIN 
execute Immediate 'alter pluggable All Open'; END;

to test                                                                                                                  

sqlshutdown immediate
sql> startup
sql> select con_idnameguidopen_mode from v$pdbs order by 1;