Hello!  How many technicians are there in total?
select count ( * ) from technician
Yes!  Can you show me their names and their machine ids that they are assigned to repair?
select t2.name, t1.machine_id from repair_assignment as t1 join technician as t2 on t1.technician_id = t2.technician_id
Great!  Also add to that list the starting year and age of each technician?
select t2.name, t1.machine_id,t2.starting_year,t2.age from repair_assignment as t1 join technician as t2 on t1.technician_id = t2.technician_id