Show me the name of each part with the number of faults it has.
select t1.part_name, count(*) from parts as t1 join part_faults as t2 on t1.part_id = t2.part_id group by t1.part_name
Show me the name of part with the least number of faults.
select t1.part_name from parts as t1 join part_faults as t2 on t1.part_id = t2.part_id group by t1.part_name order by count(*) asc limit 1