Design metrics and write SQL for a case

Use the following relational schema. The campaign under study is identified by marketing_contacts.campaign = 'fall_launch', and only contacts whose contact_time falls between 2025-09-01 and 2025-09-30 inclusive are considered. All time windows are half-open: [start, end). Tables: Illustrative sample rows: Part 1: Primary and guardrail metrics Using only each user's first fall_launch contact in the campaign window, define and compute three campaign-level metrics.…