Jack Orenstein <jao@geophile.com> writes:
> Should _PG_init(void) be declared in someplace included by postgres.h or
> fmgr.h?
No, because it's something a given module might or might not provide.
Also, a global extern might give the impression that this was a global
function that the core code provides, rather than a per-module function.
regards, tom lane