"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> The vacuum-cost-limit issue may be sufficient reason to kill this idea;
> not sure.
We already have a much higher cost for blocks that cause i/o than blocks which
don't. I think if we had zero cost for blocks which don't cause i/o it would
basically work unless the sleep time was so large that the other scans managed
to cycle through the entire ring in that time.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com