What are the name of all the reviewers?
select name from reviewer
What are the least rating stars they ever gave?
select min(stars) from rating group by rid
Also show me the title of the movies that correspond to those rating stars.
select t2.title, t1.rid, t1.stars, min(t1.stars) from rating as t1 join movie as t2 on t1.mid = t2.mid group by t1.rid