Robert Haas <robertmhaas@gmail.com> writes:
> So I think you whacked this around some more to get a *somewhat* more
> sensible behavior, but ISTM that the behavior here still not really
> right. Should we select a timezone at startup time even if we don't
> immediately need it, so that this can work correctly if we revert to
> the default down the road?
We could do that, but the issue that this code is trying to avoid is
that identify_system_timezone can easily add several seconds to the
postmaster startup time. So one of the reasons why someone would be
putting a timezone setting into postgresql.conf in the first place is
to not pay that startup overhead. I'm not thrilled with the idea
of defeating that in order to cover the corner case where they remove
the setting later.
regards, tom lane