0. A Backup Is Not a File, but a Promise You can write anything you want in the logs: backup completed successfully WAL uploaded successfully retention completed successfully archive is healthy Enter fullscreen mode Exit fullscreen mode But on the day of a real disaster, PostgreSQL will not read your beautiful logs. It will simply ask for the next WAL file. And if you cannot provide it, the whole story ends right there. This article is not about the internal implementation of a WAL receiver . There was already a separate long story about that . This article is about how I see the future development of the tool. The real question is this: Can I restore PostgreSQL from what my tool has been so confidently saving? 1. Backups Are a Comforting Lie Backups are one of the most comforting illusions in infrastructure. The command completed successfully. A file appeared in S3. There is a green line in the logs. Maybe somewhere on a dashboard, healthy is even glowing. Everyone feels relaxed and confident.…