What is better extra query or extra column in database?

[Johny11]

What is better extra query or extra column in database for data that will be available very less time.Example: In Case of sub user management either i add one extra column super_user_id in main users table and make enrty if users types are sub_user and the default column value is -1 or i create new table and manage sub user in that table.But in case of login i have to search in two tables and this i have to make one more query.Thanks