Re: Experimental patch for inter-page delay in VACUUM

> Or...  It seems to me that we have been observing something on the order 
> of 10x-20x slowdown for vacuuming a table.  I think this is WAY 
> overcompensating for the original problems, and would cause it's own 
> problem as mentioned above.   Since the granularity of delay seems to be 
> the problem can we do more work between delays? Instead of sleeping 
> after every page (I assume this is what it's doing) perhaps we should 
> sleep every 10 pages,

I also think doing more than one page per sleep is advantageous since
it would still allow the OS to do it's readahead optimizations.
I suspect those would fall flat if only one page is fetched per sleep.

Andreas