What are the creation years of the departments?
select creation from department
Which secretaries were born in Alabama?
select * from head where born_state = 'Alabama'
What are the distinct creation years of the departments managed by a secretary born in state 'Alabama'?
select distinct t1.creation from department as t1 join management as t2 on t1.department_id = t2.department_id join head as t3 on t2.head_id = t3.head_id where t3.born_state = 'Alabama'