Version upgrades and replication

Hello all!

I have a primary+replica PostgreSQL that I think work fine.

I created the replica's data directory using::

pg_basebackup -D $datadir -h $primary_host -U $replicauser \
--write-recovery-conf \
--create-slot --slot=$slotname

after creating the user on the primary (``CREATE ROLE replicauser WITH
REPLICATION PASSWORD 'password' LOGIN``) and allowing connections in
``pg_hba.conf``

Everything looks fine, changes on the primary can be seen on the
replica.

First question: what's the name of this replication mode? Every time I
try to read the documentation I get confused about which is which…

I initially created the replica on PostgreSQL 16. Yesterday I upgraded
to 17: stop the 16 primary, stop the 16 replica, ``pg_upgrade17`` on
the primary, start the 17 primary, re-do the whole base backup with
``pg_basebackup17`` on the replica, start the 17 replica, everything
works like before.

Second question: is there a better way to do that? Without having to
copy the whole cluster data again from scratch?

Thanks in advance!

--
Dakkar - <Mobilis in mobile>
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