Question about DBMS_SERVICE.START_SERVICE

Hi,

Context: one CDB and one PDB - Oracle 19c and EBS 12.2

tnsnames file with the service <PDB_service_name>.

Actions:

alter session set container = <PDB_SID>;

SQL*Plus> DBMS_SERVICE.START_SERVICE (<PDB_service_name>);

1. Is it mandatory to execute "ALTER SYSTEM REGISTER" afterwards? OR
2. Is the service definitely registered in the database and this service will be automatically UP when calling the standard EBS script adstrtall.sh?

Thanks in advance,

Armel