Using following code can get the employee information in Oracle HCM, in real time, what we can do is to use this as a data feed, and bulk update the employee information using some scripting language

select pu.user_id, papf.person_id, pu.user_guid, papf.person_number, pu.username, pea.email_address
from per_all_people_f papf, per_users pu, per_email_addresses pea
where papf.person_id = pu.person_id
and pu.person_id = pea.person_id