Table: tv_show_ratings
Columns: episode
air_date
timeslot
rating
share
18_49_rating_share
viewers_m
rank

Question: What is the rank for the show aired on May 19, 2009?
SQL: SELECT "rank" FROM tv_show_ratings WHERE "air_date" = 'may 19, 2009'

Question: What is the timeslot for the episode that aired April 28, 2009?
SQL: SELECT "timeslot" FROM tv_show_ratings WHERE "air_date" = 'april 28, 2009'

Question: What is the share of the 18-49 (Rating/Share) of 0.8/3?
SQL: SELECT "share" FROM tv_show_ratings WHERE "18_49_rating_share" = '0.8/3'

Question: What is the rating of the show ranked tba, aired on April 21, 2009?
SQL: SELECT "rating" FROM tv_show_ratings WHERE "rank" = 'tba' AND "air_date" = 'april 21, 2009'