Nikolas Everett <nik9000(at)gmail(dot)com> writes:
> We straced the backend during the explain and it looked like the open
> commands were taking several seconds each.
Kind of makes me wonder if you have a whole lot of tables ("whole lot"
in this context probably means tens of thousands) and are storing the
database on a filesystem that doesn't scale well to lots of files in one
directory. If that's the explanation, the reason the 8.3 installation
was okay was likely that it was stored on a more modern filesystem.
BTW, please keep the list cc'd on replies.
regards, tom lane