SQL Top Regions by Downtime

Write a SQL query to find the top 3 regions by network downtime, partitioned by month.

Use completed downtime events only. Calculate each event's duration in minutes and assign it to the month in which it started. Return the three highest-downtime regions for each month, with deterministic ordering for ties.

Output

1. One row per selected region and month
2. Columns: month, region_name, total_downtime_minutes, and region_rank
3. Include only ranks 1 through 3, ordered by month ascending, rank ascending, and region name ascending

Output details

• Treat an event as completed only when ended_at is non-NULL and strictly later than started_at.
• Format month as YYYY-MM.
• Round total_downtime_minutes to exactly 2 decimal places.
• Break equal downtime totals by region_name ascending before assigning region_rank.