Process for Large Datasets with SQL or Python | Dataford Interview Questions

Explain your process for handling large datasets using SQL or Python.

For the SQL portion, use the provided users and events tables to summarize valid events during January and February 2026. Include only user-linked events with a non-null event type and retain months and countries meeting the minimum activity requirement.

Output

One row per month and country with at least two valid events
Columns: month, country, event_count, active_users, avg_payload_kb
Sort by month, then country

Schema

users

Column	Type	Description
user_idPK	INT	Unique user identifier
country	VARCHAR(50)	User country

events

Column	Type	Description
event_idPK	INT	Unique event identifier
user_id	INT	User associated with the event
event_ts	TIMESTAMP	Event timestamp
event_type	VARCHAR(30)	Type of recorded event
payload_kb	DECIMAL(10,2)	Event payload size in kilobytes

Your question is Process for Large Datasets with SQL or Python. Start with the requirements and the two tables in the Question tab.

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Problem