As an analyst, you give high priority to retention. CQL allows you to easily create retention rate trends. Below is an example of a trend over 2nd day retention.
SELECT right(cohort_name,5) as Month_Day, cohort_id, cohort_size, bucket_id, (COUNT(DISTINCT user_id)/cohort_size)*100 AS Percent FROM cooladata WHERE date_range(doc.date_range) CLUSTER COHORT BY 1 DAYS EACH STARTS WITH event_name = "user_login" FOLLOWED BY event_name = "level_up" BUCKET BY 1 DAYS ALL HAVING (cohort_id < 60 AND bucket_id=1) GROUP BY 1,2,3,4 ORDER BY 2
Use bucket_id=6 to look at 7-day retention, and bucket_id=29 to look at 30-day retention.