Problem 1: [20 pt] Relational algebra. Following is the schema for character- episode-appearance relation. Characters(name, type): assume characters have distinctive names. name type Bob A JonA Emma B Olivia C Appearances (name, season, num) ame season num Bob 1 Bob 1 Jon Episodes(season, num, title, viewers) Jon 2 Emma1 Emma 1 Emma2 Bob 2 Olivia 2 season num title viewers Winter 2.5 M King 2.5 M Notes 4.0 M 2 Lands 3.2M 2 a)[5 pt] Find good episodes: find the episodes that have more than 3.0M viewers Sort by viewers in descending order, then by season in ascending order, and finally by number in ascending order. Format of each output row: (season, number, title, viewers) b)[5 pt] Find lucky characters: List names (remove duplicate) who appear in some episode with viewers 3.0M. Format of each output row: (name). c)[5 pt] Find the number of unique characters for each episode. Format of eaclh output row: (season, num, number_characters) d)[5 pt] Find the number of unique characters for each episode, such that there are at least two unique characters in that episode. Format of each output row: (season, num, number_characters) e)[5 pt] For each episode, find the number of unique characters whose type is A. Format of each output row: (season, num, number_characters) f [5pt] Find seasons (remove duplicate) in which Type A characters have NEVER appeared. Format of each output row: (season)