A cinema asked us for help. They have the following table:

CREATE TABLE movie (
  id integer PRIMARY KEY,
  title varchar(128),
  genre varchar(32),
  rating decimal(3, 1)
);

Their database performance is getting worse as the number of movies increases. The query that the cinema needs to optimize searches for a given movie genre and then looks for the highest ratings.

Your task is to create a multi-column index named genre_rating_index. The rating column should be indexed in descending order, with NULL values last.