CREATE TABLE reviewer (rid NUMBER, name CLOB)
CREATE TABLE movie (mid NUMBER, title CLOB, year NUMBER, director CLOB)
CREATE TABLE rating (rid NUMBER, mid NUMBER, stars NUMBER, ratingdate TIME)

What is the average number of stars that each reviewer awards for a movie?
SELECT T2.name, AVG(T1.stars) FROM rating AS T1 JOIN reviewer AS T2 ON T1.rid = T2.rid GROUP BY T2.name
SELECT "T2"."name", AVG("T1"."stars") FROM "rating" "T1" JOIN "reviewer" "T2" ON "T1"."rid" = "T2"."rid" GROUP BY "T2"."name"