Christopher Browne <cbbrowne@libertyrms.info> writes:
> The advantage of the per-page delay is that performance is not being
> "totally hammered" by the vacuum. If things are so busy that it's an
> issue, the system is liable to "limp somewhat," but that's not as bad
> as what we see now, where VACUUM and other activity are 'dueling' for
> access to I/O. Per-page delay means that VACUUM mostly defers to the
> other activity, limiting how badly it hurts other performance.
... or that's the theory, anyway. The point of putting up this patch
is for people to experiment to find out if it really helps.
regards, tom lane