Re: Changing shared_buffers without restart

On Wed, 27 Nov 2024 at 22:06, Robert Haas <robertmhaas@gmail.com> wrote:
> If we had an upper bound on the size of shared_buffers

I think a fairly reliable upper bound is the amount of physical memory
on the system at time of postmaster start. We could make it a GUC to
set the upper bound for the rare cases where people do stuff like
adding swap space later or doing online VM growth. We could even have
the default be something like 4x the physical memory to accommodate
those people by default.

> reserve that amount of address space at startup time but only actually
> map a portion of it

Or is this the difficult part?