You can definitely use LISTEN and NOTIFY to watch for changes in Postgres. Here's a presentation I did on that last year, though oriented more towards web apps than analytics. https://www.youtube.com/watch?v=PsorlkAF83s

For analytics I would want stronger guarantees than LISTEN and NOTIFY alone can provide. I explore options for that here: http://btubbs.com/streaming-updates-from-postgres.html