I don't see the problem. All variables are either set in config or at runtime and then for every new query they are read and used by PostgreSQL (at least this i

I don't see the problem. All variables are either set in config or at runtime and then for every new query they are read and used by PostgreSQL (at least this is my understanding). Regarding the threading issue, I think you can do the connections part multithreaded instead of one process per connection and still use IPC between this and postmaster. Because of the way PostgreSQL currently works, seems feasible to move parts one by one into a threaded model and instead of tens/hundreds of processes you can have just a few and a lot of threads. Honestly, they should prototype it and see how it looks like and then decide on the way forward.