Hi, Sorry for showing up this late, but I'm a bit confused with the new situation.
Unless I'm missing something, the new situation is that the system is supposed to prevent access to MaxBackends during s_p_l_pg_init, for reasons I totally agree with, but without doing anything for extensions that actually need to access it at that time. So what are extensions supposed to do now if they do need the information during their _PG_init() / RequestAddinShmemSpace()? Note that I have two of such extensions. They actually only need it to give access to the queryid in the background workers since it's otherwise not available, but there's at least pg_wait_sampling extension that needs the value to request shmem for other needs. One funny note is that my extensions aren't using MaxBackends but instead compute it based on MaxConnections, autovacuum_max_workers and so on. So those two extensions aren't currently broken, or more accurately not more than they previously were. Is there any reasoning to not protect all the variables that contribute to MaxBackends?
