Re: make MaxBackends available in _PG_init

Nathan Bossart <nathandbossart@gmail.com> writes:
> On Tue, Apr 12, 2022 at 03:12:42PM -0400, Robert Haas wrote:
>> But if there's even one use case where adjusting GUCs at this phase is
>> reasonable, then 0003 isn't really good enough. We need an 0004 that
>> provides a new hook in a place where such changes can safely be made.

> I think that is doable.  IMO it should be ѕomething like _PG_change_GUCs()
> that is called before _PG_init().  The other option is to add a hook called
> after _PG_init() where MaxBackends is available (in which case we likely
> want GetMaxBackends() again).  Thoughts?

I like the second option.  Calling into a module before we've called its
_PG_init function is just weird, and will cause no end of confusion.

            regards, tom lane