Yes but they can’t be shared. If you size your pool to hold 10 connections (because asyncio can handle that and more), then deploy with uvicorn —-workers 4 (which should match the number of cores on your app server), and then deploy to 3 app servers (for redundancy) then you’ve now got 120 open connections to Postgres. Run anything more than a trivial query and you’re easily at gigabytes of ram.
120 connections is likely fine. If it's not, you could do only 5 connections per worker. This is more of a problem if you have uneven load on the workers though.
I’m not claiming it’s not fine, but it is a surprising consideration for a relatively small deployment. You have to start planning around Postgres’ architecture for anything larger, hence the solution in PgBouncer.
