Re: Performance features the 4th

----- Original Message ----- 
From: "Jan Wieck" <JanWieck@Yahoo.com>
> Tom Lane wrote:
> > Gaetano and a couple of other people did experiments that seemed to show
> > it was useful.  I think we'd want to change the shape of the knob per
> > later suggestions (sleep 10 ms every N blocks, instead of N ms every
> > block) but it did seem that there was useful bang for little buck there.
>
> I thought it was "sleep N ms every M blocks".
>
> Have we seen any numbers? Anything at all? Something that gives us a
> clue by what factor one has to multiply the total time a "VACUUM
> ANALYZE" takes, to get what effect in return?

I have some time on sunday to do some testing.  Is there a patch that I can
apply that implements either of the two options? (sleep 10ms every M blocks
or sleep N ms every M blocks).

I know Tom posted the original patch that sleept N ms every 1 block (where N
is > 10 due to OS limitations).  Jan can you post a patch that has just the
sleep code in it? Or should it be easy enough for me to cull out of the
larger patch you posted?