The current pool implementation doesn't really keep connections open, so it doesn't reduce latency at all when more than one connection is needed. This issue was first reported upstream two years ago in psycopg/psycopg2#563 and a fix was proposed in psycopg/psycopg2#565, but it wasn't merged. I submitted a rebased and improved version of that PR last week in psycopg/psycopg2#974, but the maintainer hasn't responded to it. So, I'm probably going to release the new pool implementation as a separate package, then add that package as a dependency to postgres.py.