oracle rollback

1-- Rollback (cancellation)
2DELETE FROM employees WHERE employee_id = 123;    -- Done in current session
3ROLLBACK;                                         -- Cancelled in current session
4SELECT * FROM employees WHERE employee_id = 123;  -- Found
5-- Commit (validation)
6DELETE FROM employees WHERE employee_id = 123;    -- Done in current session
7COMMIT;                                           -- Visible for ALL sessions
8SELECT * FROM employees WHERE employee_id = 123;  -- Missing for ALL sessions