Clean Event Statuses for Analysis | Dataford Interview Questions

You are given a raw event log exported from Databricks SQL where status values are inconsistent and some rows are not ready for analysis. Write a PostgreSQL query that returns the number of usable events per cleaned status. Treat status values case-insensitively, trim surrounding spaces, exclude rows where the cleaned status is empty or NULL, and only keep rows with a non-NULL event_date. Return the cleaned status and the event count, ordered by event count descending and cleaned status ascending.

Schema

event_log

Column	Type	Description
event_idPK	INT	Unique event identifier
raw_status	VARCHAR(50)	Raw status text before cleaning
event_date	DATE	Date the event was recorded
source_system	VARCHAR(30)	Databricks surface that produced the row

Your question is Clean Event Statuses for Analysis. 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

Schema

event_log

Column	Type	Description
event_idPK	INT	Unique event identifier
raw_status	VARCHAR(50)	Raw status text before cleaning
event_date	DATE	Date the event was recorded
source_system	VARCHAR(30)	Databricks surface that produced the row

Your question is Clean Event Statuses for Analysis. 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.