No. It will be internal port to port connection. And it also depends on the driver. You can definitely have a crappy SQLite driver for your obscure OS that can absolutely take a lot of time for those 200 queries.
It is still IPC (inter-process communication) even though it wont go over any network. Probably still order of magnitude more overhead than a function call, but quite possibly it will be acceptable.
None is stopping you to write a PGSQL driver that uses memory-mapped files and then your calls are as fast as a function call.