Michael Riess writes:
Sorry, I should have included that info in the initial post. You're
right in that most of these tables have a similar structure. But they
are independent and can be customized by the users.
How about creating 50 databases and give each it's own tablespace?
It's not only whether PostgreSQL can be optimized, but also how well your
filesystem is handling the directory with large number of files. by
splitting the directories you will likely help the OS and will be able to
perhaps better determine if the OS or the DB is at fault for the slowness.