Show all faculty ids
select facid from faculty
faculty Ids  who have at least 2 students
select t1.facid from faculty as t1 join student as t2 on t1.facid = t2.advisor group by t1.facid having count ( * ) > = 2
yes
select t2.major from faculty as t1 join student as t2 on t1.facid = t2.advisor group by t1.facid having count ( * ) > = 2