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

Christopher Browne <cbbrowne(at)libertyrms(dot)info> writes:

> VACUUM is like putting an extra few transport trucks onto the highway.
> It may only go from one highway junction to the next, and be fairly
> brief, if traffic is moving well. But if traffic is heavy, it adds to
> the congestion. (And that's as far as the analogy can go; I can't
> imagine a way of drawing the GUC parameter into this...)

Ooh strained metaphors. This game is always fun.

So I think of it the other way around. A busy database is like downtown
traffic with everyone going every which way for short trips. Running vacuum is
like having a few trucks driving through your city streets for through
traffic.

Having a parameter to slow down the through traffic is like, uh, having
express lanes for local traffic. er, yeah, that's the ticket. Except who ever
heard of having express lanes for local traffic. Hm.

--
greg