"Matthew T. O'Connor" <matthew@zeut.net> writes:
> interesting thought. I think this boils down to how many knobs do we
> need to put on this system. It might make sense to say allow upto X
> concurrent vacuums, a 4 processor system might handle 4 concurrent
> vacuums very well.
This is almost certainly a bad idea. vacuum is not very
processor-intensive, but it is disk-intensive. Multiple vacuums running
at once will suck more disk bandwidth than is appropriate for a
"background" operation, no matter how sexy your CPU is. I can't see
any reason to allow more than one auto-scheduled vacuum at a time.
regards, tom lane