On Thu, Nov 18, 2021 at 5:34 AM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
> The startup process main function looks to be to do some
> initialization required for recovery and do the recovery, exit if it
> is a crash recovery or stay there if it is a standby recovery. Apart
> from these I'm not sure it does any non-recovery tasks. Does the
> startup process have any relevance or work to do if the server state
> is DB_SHUTDOWNED i.e the server was shutdown properly? I think yes,
> although it doesn't enter the recovery/REDO loop, it does a bunch of
> other things like updating the control file, pre-allocating WAL files,
> updating shared memory state to allow other backends to write WAL and
> so on.
That's true, but those tasks are very brief. Nobody's going to get too
confused by a "recovery" process that shows up for a few milliseconds
when there's no recovery to be done. Having a "startup" process that
sticks around forever on a standy, though, actually is confusing.
--
Robert Haas
EDB: http://www.enterprisedb.com