Question: Within the user who joined Yelp in 2004, explore the user ID with average star of 5 and it's review length on the business.
SQL: SELECT T2.user_id, T2.review_length FROM Users AS T1 INNER JOIN Reviews AS T2 ON T1.user_id = T2.user_id WHERE T1.user_yelping_since_year = 2004 AND T1.user_average_stars = 5