What are the titles and directors of the movies whose star is greater than the average stars of the movies directed by James Cameron?
select t2.title, t2.director from rating as t1 join movie as t2 on t1.mid = t2.mid where t1.stars > (select avg(t1.stars) from rating as t1 join movie as t2 on t1.mid = t2.mid where t2.director = "James Cameron")