Simon Riggs <simon@2ndQuadrant.com> writes:
> On Tue, 2009-09-01 at 09:58 -0400, Tom Lane wrote:
>> We get beat up on a regular basis about "spikes" in response time;
>> why would you want to have vacuum creating one when it doesn't need
>> to?
> If one I/O on a background utility can cause such a spike, we are in
> serious shitake. I would be more comfortable if the various important
> things VACUUM does were protected by sync commit. I see no reason to
> optimise away one I/O just because we might theoretically do so. Any
> mistake in the theory and we are exposed. Why take the risk?
*WHAT* risk? Most vacuums do not do a sync commit, and never have.
regards, tom lane