Seemed straightforward at first but you have to be careful about counting distinct recipients, not just total calls.
Clarify the schema and definitions (e.g., what constitutes a call, how to handle multiple calls to the same person, and the exact time window). Then write a SQL query that filters calls from the past week, counts distinct recipients per caller, and selects those with 3 or more distinct recipients.
Pro tip: Mention that you would verify the time window boundaries (e.g., using 'now() - interval '7 days'') and consider time zones if the data is stored in UTC. Also, discuss how to handle edge cases like null recipients or calls to oneself.
Ask about the table structure (e.g., call logs with caller_id, recipient_id, timestamp) and define 'past week' (e.g., last 7 days from current time). Confirm whether multiple calls to the same person count as one distinct recipient.
Use a WHERE clause to select only calls where the timestamp is within the past week, e.g., timestamp >= NOW() - INTERVAL '7 days'.
Group by caller_id and count distinct recipient_id to get the number of unique people each user called.
Apply a HAVING clause to keep only groups where the distinct count is >= 3.
Wrap the previous query in a subquery or use COUNT(*) OVER () to get the total number of users meeting the condition.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.