Re: language cleanups in code and docs

On Wed, Jun 17, 2020 at 01:59:26PM -0400, Robert Haas wrote:
> On Mon, Jun 15, 2020 at 2:23 PM Andres Freund <andres@anarazel.de> wrote:
> > 0002: code: s/master/primary/
> > 0003: code: s/master/leader/
> > 0006: docs: s/master/root/
> > 0007: docs: s/master/supervisor/
> 
> I'd just like to make the pointer here that there's value in trying to
> use different terminology for different things. I picked "leader" and
> "worker" for parallel query and tried to use them consistently because
> "master" and "slave" were being used widely to refer to physical
> replication, and I thought it would be clearer to use something
> different, so I did. It's confusing if we use the same word for the
> server from which others replicate, the table from which others
> inherit, the process which initiates parallelism, and the first
> process that is launched across the whole cluster, regardless of
> *which* word we use for those things. So, I think there is every
> possibility that with careful thought, we can actually make things
> clearer, in addition to avoiding the use of terms that are no longer
> welcome.

I think the question is whether we can improve our terms as part of this
rewording, or if we make them worse.  When we got rid of slave and made
it standby, I think we made things worse since many of the replicas were
not functioning for the purpose of standby.  Standby is a role, not a
status, while replica is a status.

The other issue is how the terms interlink with other terms.  When we
used master/slave, multi-master matched the wording, but replication
didn't match.  If we go with replica, replication works, and
primary/replica kind of fits, e.g., master/replica does not.
Multi-master then no longer fits, multi-primary sounds odd, and
active-active doesn't match, though active-active is not used as much as
primary/replica, so maybe that is OK.  Ideally we would have all terms
matching, but maybe that is impossible.

My point is that these terms are symbolic (similes) --- the new terms
should link to their roles and to other terms in a logical way.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee