On Mon, Apr 25, 2022 at 2:15 AM Michael Paquier <michael@paquier.xyz> wrote:
On Fri, Apr 22, 2022 at 09:49:34AM +0200, Magnus Hagander wrote: > I agree that thats a very narrow use case. And I'm not sure the use case of > a running server is even that important here - it's really the offline one > that's important. Or rather, the really compelling one is when there is a > server running but I want to check the value offline because it will > change. SHOW doesn't help there because it shows the value based on the > currently running configuration, not the new one after a restart.
You mean the case of a server where one would directly change postgresql.conf on a running server, and use postgres -C to see how much the kernel settings need to be changed before the restart?
Yes.
AIUI that was the original use-case for this feature. It certainly was for me :)
> Hmm. So what's the solution on windows? I guess maybe it's not as important > there because there is no limit on huge pages, but generally getting the > expected shared memory usage might be useful? Just significantly less > important.
Contrary to Linux, we don't need to care about the number of large pages that are necessary because there is no equivalent of vm.nr_hugepages on Windows (see [1]), do we? If that were the case, we'd have a use case for huge_page_size, additionally.
Right, for this one in particular -- that's what I meant with my comment about there not being a limit. But this feature works for other settings as well, not just the huge pages one. Exactly what the use-cases are can vary, but surely they would have the same problems wrt redirects?
