Re: Overhauling GUCS

Greg,

> At least that way we could always steal more if we want or return some, as
> long as we're careful about when we do it. That would open the door to having
> these parameters be dynamically adjustable. That alone would be worthwhile
> even if we bypass all bells and whistles of the buffer manager.
> 

One hitch, though, is that asynchronous commit could consume big chunks 
of shared_buffers.  So we might still need a limit for people who are 
using async.

--Josh