Style matters.
Compare these 2 queries (which do the same thing):
WITH ab_test_categorization AS ( SELECT user_id, custom_parameters ->> 'ab_test_name' AS ab_test_name, custom_parameters ->> 'ab_test_variation' AS ab_test_variation, created_at AS categorized_at FROM mobile_analytics.events WHERE custom_parameters ->> 'ab_test_name' IS NOT NULL AND action = 'signup' ) SELECT ab_test_variation, COUNT(DISTINCT(user_id)) FROM ab_test_categorization WHERE ab_test_name = 'longer_onboarding_201803' GROUP BY 1
SELECT ab_test_variation,...