Top 5% Clients by Volume | Dataford Interview Questions

Write a query to identify the top 5% of clients by transaction volume over the last quarter.

Treat transaction volume as the number of transactions. Use the previous completed calendar quarter relative to the query execution date. Include only clients with at least one transaction during that quarter.

Output

One row per selected client with client_id, client_name, and transaction_volume.
Include the highest-volume 5% of clients, rounding the selection count up to at least one client.
Order by transaction_volume descending, then client_id ascending to break ties.

Schema

clients

Column	Type	Description
client_idPK	INT	Unique client identifier
client_name	VARCHAR(100)	Client display name
status	VARCHAR(20)	Current client status

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
client_id	INT	Client associated with the transaction
transaction_date	DATE	Date on which the transaction occurred
amount	NUMERIC(12,2)	Illustrative transaction amount

Your question is Top 5% Clients by Volume. Start with the requirements and the two 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