Top Wells Per Region SQL | Dataford Interview Questions

Write a query to find the top three highest-performing oil wells per region using window functions.

Treat performance as the total recorded barrels produced by each well. Use the provided wells and well_production tables.

Output

Return one row per selected well with region, well_id, well_name, total_production, and performance_rank.
Include at most three wells per region, ordered by region, rank, and well ID.
Break equal production totals by ascending well_id.

wells

Column	Type	Description
well_idPK	INT	Unique identifier for the oil well
region	VARCHAR(100)	Operational region containing the well
well_name	VARCHAR(150)	Name assigned to the well

well_production

Column	Type	Description
production_idPK	INT	Unique production record identifier
well_id	INT	Referenced oil well
production_date	DATE	Date of the production measurement
barrels	NUMERIC(12,0)	Barrels produced during the measurement period

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