Listen/notify in Postgres is an incredible feature that makes itself useful in all kinds of situations. I’ve been using it a long time, started taking it for granted long ago, and was somewhat shocked recently looking into MySQL and SQLite to learn that even in 2024, no equivalent exists. In a basic sense, listen/notify is such a simple concept that it needs little explanation. Clients subscribe on topics and other clients can send on topics, passing a message to each subscribed client. The idea...