SQL for Peak Generation Ranking | Dataford Interview Questions

Write a SQL query to identify peak power generation intervals across multiple wind farms at Nextera Energy Resources, ranking them by daily output.

Use the provided wind farm and generation interval data. Return only the highest-output interval for each farm on each date. If intervals tie, select the earliest interval.

Output

One row per wind farm and generation date with available readings
Columns: farm_id, farm_name, generation_date, peak_interval_start, peak_output_mwh, daily_output_mwh, and daily_rank
Rank farms within each date by descending daily output, with ties sharing a rank
Order by generation_date, daily_rank, and farm_id

Schema

wind_farms

Column	Type	Description
farm_idPK	INT	Unique identifier for the wind farm
farm_name	VARCHAR(100)	Name of the wind farm
region	VARCHAR(60)	Operating region of the wind farm

power_generation

Column	Type	Description
interval_idPK	INT	Unique identifier for the generation interval
farm_id	INT	Referenced wind farm identifier
interval_start	TIMESTAMP	Start timestamp of the generation interval
generated_mwh	DECIMAL(12,2)	Energy generated during the interval in megawatt-hours

Your question is SQL for Peak Generation Ranking. Start with the requirements and the two tables in the Question tab.

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Problem