Query High-Traffic Services for January 2026

Describe your approach to optimizing database queries for high-traffic services.

Using the provided service and request data, write a PostgreSQL query that returns services with at least two requests during January 2026. Include only requests in that date range. The result should support evaluating traffic, latency, and server errors.

Output

1. One row per qualifying service
2. Columns: service_name, request_count, avg_duration_ms, error_rate_pct
3. Sort by request count descending, then service name ascending

Output details

• Treat January's bounds as inclusive at 2026-01-01 00:00:00 and exclusive at 2026-02-01 00:00:00.
• Round avg_duration_ms to two decimal places.
• Calculate error_rate_pct as the percentage of requests with status_code >= 500, rounded to two decimal places.