Scott Marlowe <smarlowe(at)g2switchworks(dot)com> writes:
> The most common cause of these problems is that you have long standing
> transactions that never get closed.
That can cause table bloat but it shouldn't have anything to do with XID
wraparound problems. My guess is that the vacuum attempts are failing
somewhere along the line, and that some perusal of the postmaster log
would shed light on the issue.
regards, tom lane