On Wed, Nov 27, 2024 at 4:28 PM Jelte Fennema-Nio <postg...@jeltef.nl> wrote: > On Wed, 27 Nov 2024 at 22:06, Robert Haas <robertmh...@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.
Yes, Peter mentioned similar ideas on this thread last week. > > reserve that amount of address space at startup time but only actually > > map a portion of it > > Or is this the difficult part? I'm not sure how difficult this is, although I'm pretty sure that it's more difficult than adding a GUC. My point wasn't so much whether this is easy or hard but rather that it's essential if you want to avoid having addresses change when the resizing happens. -- Robert Haas EDB: http://www.enterprisedb.com
