Re: Re: [COMMITTERS] pgsql: Start background writer during archive recovery.

Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> Tom Lane wrote:
>>> Maybe the postmaster should wait for startup process exit before
>>> deciding to open for business, instead of just a signal.
>
>> Not a bad idea. Although, there's nothing wrong with the current way
>> either. The startup process does a proc_exit(0) right after sending the
>> signal ATM, so there's no real work left at that point.
>
> The thing wrong with it is assuming that nothing interesting will happen
> during proc_exit(). We hang enough stuff on on_proc_exit hooks that
> that seems like a pretty shaky assumption.

I can't get too worried, given that proc_exit() is a very well-beaten
code path. Admittedly not so much for an auxiliary process, but that's
just a dumbed down version of what happens with a full-blown backend.

However I started looking into that idea anyway, and figured that it
does simplify the logic in postmaster.c quite a bit, so I think it's
worth doing on those grounds alone. Attached is a patch against CVS HEAD
and also against a snapshot before the recovery infra patch, for easier
reading. I'll give that some more testing and commit if I find no issues.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com