This query can help with the "homework" tag cleanup. Each tag listed in this result is associated with the given number of "homework" questions.
Q&A for programmers
select count(*), at.tagname
from posttags a
join posttags b on (a.postid = b.postid)
join tags at on (a.tagid = at.id)
join tags bt on (b.tagid = bt.id)
where bt.tagname = 'homework' and at.tagname <> 'homework'
group by at.tagname
order by 1 desc;