"Jim C. Nasby" <jim@nasby.net> writes:
> The proposal to save enough state to be able to resume a vacuum at
> pretty much any point in it's cycle might work; we'd have to benchmark
> it. With the default maintenance_work_mem of 128M it would mean writing
> out 64M of state every minute on average, which is likely to take
> several seconds to fsync (though, maybe we wouldn't need to fsync it...)
Which is exactly why we needn't bother benchmarking it. Even if it
weren't complex and unsafe, it will be a net loss when you consider the
fact that it adds I/O instead of removing it.
regards, tom lane