Interview Guides
You are given release records and application error logs. Write a PostgreSQL query that compares error volume in the 7 days before each release to the 7 days after it, and returns the release version, release date, pre-release error count, post-release error count, and the percentage change in error volume.
Use the release date as the boundary: the pre-release window is the 7 full days before the release date, and the post-release window is the 7 full days starting on the release date. Exclude releases that do not have any error logs in either window.
