SQL for Good Users

Taboola wants to identify highly engaged users of Taboola Ads Manager. A Good User is a user whose average number of sessions per observed week is at least 3. Calculate the average session duration for each Good User.

Write a PostgreSQL query using the sessions table.

Requirements

1. Group sessions by userId and calendar week, where weeks begin on Monday.
2. Calculate each user's average weekly session count across weeks in which that user had at least one session.
3. Keep only users whose average weekly session count is at least 3.
4. Return each qualifying userId and their average session duration across all recorded sessions.
5. Ignore rows with a null userId or null data_timestamp. PostgreSQL's AVG should ignore null durations.
6. Sort the output by userId in ascending order.