SQL Vendor Performance Query

Write a SQL query to analyze operational performance by vendor at Scale, including throughput, average turnaround time, and error rate over time. Use the provided vendor and job data. Treat completed and error jobs as processed, calculate turnaround time for completed jobs, and exclude in-progress jobs from throughput and error-rate calculations.

Output

1. One row per vendor and month with processed jobs.
2. Columns: vendor_name, period_month, throughput, average_turnaround_minutes, and error_rate_pct.
3. Sort by vendor_name, then period_month ascending.

Output details

• Restrict jobs to completed_at >= TIMESTAMP '2025-01-01 00:00:00' and < TIMESTAMP '2025-04-01 00:00:00'.
• Derive period_month as the first day of the month containing completed_at.
• Include vendor-month rows with zero processed jobs, returning NULL for average_turnaround_minutes and error_rate_pct.
• Round average_turnaround_minutes and error_rate_pct to two decimal places.
• Exclude completed jobs missing started_at or completed_at from the turnaround average.