Have you considered implementing this with database triggers instead of in your application logic?
Requires a bit of brainpower to set up a system around it, but it makes your application logic dramatically simpler.
(You don't have to remember to update `foo.bar` every time you write a function that touches `moo.bar`, and if you run migrations in SQL, the updates will also cascade naturally).
It's really high up on my personal wish list for Postgres to support incrementally-materialized views. It doesn't seem like it would be impossible to implement (since, as I suggested, you can implement it on your own with triggers), but IDK, I assume there are higher-priority issues on their docket.
