Abhijit Menon-Sen <ams(at)2ndquadrant(dot)com> writes:
> In the past, we've had situations where "everything is hung" turned out
> to be because of a script that ran manual VACUUM that was holding some
> lock. It's admittedly not a huge problem, but it might be useful if a
> manual VACUUM could be cancelled the way autovacuum can be.
I think the real answer to that is "stop using manual VACUUM".
regards, tom lane