Handle Dataset Duplicates | Dataford Interview Questions

Explain how you would handle duplicates in a dataset at Epsilon.

Using the provided epsilon_events table, identify duplicate records based on matching customer_id, event_date, event_type, and event_value. Report each duplicated value combination and how many rows could be removed while retaining one copy.

Output

One row per duplicated value combination.
Columns: customer_id, event_date, event_type, event_value, duplicate_count, and removable_count.
Include only combinations appearing more than once, ordered by customer_id, event_date, event_type, and event_value.

Schema

epsilon_events

Column	Type	Description
event_idPK	INT	Unique stored row identifier
customer_id	INT	Identifier of the customer associated with the event
event_date	DATE	Date on which the event occurred
event_type	VARCHAR(50)	Type of event
event_value	NUMERIC(10,2)	Optional numeric value recorded for the event

Your question is Handle Dataset Duplicates. Start with the requirements and the one table 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

Explain how you would handle duplicates in a dataset at Epsilon.

Output

One row per duplicated value combination.
Columns: customer_id, event_date, event_type, event_value, duplicate_count, and removable_count.
Include only combinations appearing more than once, ordered by customer_id, event_date, event_type, and event_value.

Schema

epsilon_events

Column	Type	Description
event_idPK	INT	Unique stored row identifier
customer_id	INT	Identifier of the customer associated with the event
event_date	DATE	Date on which the event occurred
event_type	VARCHAR(50)	Type of event
event_value	NUMERIC(10,2)	Optional numeric value recorded for the event

Your question is Handle Dataset Duplicates. Start with the requirements and the one table 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.