Table: tv_episode_ratings_9
Columns: series
season
title
written_by
original_air_date
u_s_viewers_millions

Question: who wrote the episode "he ain't heavy"?
SQL: SELECT "written_by" FROM tv_episode_ratings_9 WHERE "title" = '"He Ain''t Heavy"'

Question: how many times was the episode "the old maid of honor" originally aired?
SQL: SELECT COUNT("original_air_date") FROM tv_episode_ratings_9 WHERE "title" = '"The Old Maid of Honor"'

Question: the episode "a change in heart/pants" had a maximum of what number in the series?
SQL: SELECT MAX("series") FROM tv_episode_ratings_9 WHERE "title" = '"A Change in Heart/Pants"'