Before I try to answer that, I need to know how the scheduler works.
As I understand the term used, there is no scheduler inside Postgres for user connections -- they're handled by the OS kernel.
Then, I'm probably using the wrong term. Right now, I have max_worker_processes set to 16. What happens when query #17 wants some work done? What do you call the thing that handles that? What is its algorithm for allocating work to the processes? Or am I completely misunderstanding the role worker processes play in execution? Joseph Wagner