Re: Some thoughts about i/o priorities and throttling vacuum

Shridhar Daithankar <shridhar_daithankar(at)persistent(dot)co(dot)in> writes:
> I agree. This seems to be the best way of dealing with things. Of course,
> probably there are details we are missing here, but in general its good.

Actually, this is all pure handwaving, because you are ignoring the need
to remove index tuples. The existing VACUUM code amortizes index
cleanup over as many tuples as it can. If you do partial vacuuming of
tables then you are necessarily going to be expending more cycles (and
I/O) per tuple, on average, to get rid of the index entries. It's not
at all clear that there's any real win to be had in that direction.
Perhaps it's a win, but you have no evidence on which to assert so.

regards, tom lane