Compare Vendor and Queue Performance | Dataford Interview Questions

You are given ticket-level operational data and need to compare performance across vendors and queues. Write a PostgreSQL query that returns each vendor and queue pair with the number of tickets handled, average handle time in minutes, and resolution rate for tickets created in the last 30 days. Exclude tickets that are still open, and sort the result by highest resolution rate, then lowest average handle time.

Schema

tickets

Column	Type	Description
ticket_idPK	INT	Primary key for each ticket
vendor_id	INT	References the vendor that handled the ticket
queue_id	INT	References the queue the ticket was routed to
created_at	TIMESTAMP	Ticket creation timestamp
closed_at	TIMESTAMP	Ticket close timestamp, nullable if still open
status	VARCHAR(20)	Ticket status such as open, closed, or pending
handle_time_minutes	INT	Time spent handling the ticket

vendors

Column	Type	Description
vendor_idPK	INT	Primary key for each vendor
vendor_name	VARCHAR(100)	Vendor name

queues

Column	Type	Description
queue_idPK	INT	Primary key for each queue
queue_name	VARCHAR(100)	Queue name

Your question is Compare Vendor and Queue Performance. Start with the requirements and the three tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem