From: Amit Kapila <amit.kapila16@gmail.com>
> So you want your users to shutdown and restart the server before Copy
> because that would be required if you want to change the wal_level.
Yes. They seem to be fine with it, as far as I heard from a person who is involved in the system design.
> However, even if we do that, users who are running the server
> previously with wal_level as 'replica' won't be happy after doing this
> change. Because if they change the wal_level to 'none' for certain
> operations like bulk load and then again change back the mode to
> 'replica' they need to back up the database again to setup 'replica'
> as they can't continue replication from the previous point (consider
> update on a page for which previously WAL was not written).
Yes, it requires the database backup. The database backup should be a daily task anyway, so I expect it wouldn't
imposeextra maintenance burdon on the user. Plus, not all users use the streaming replication for HA. I think it's
helpfulfor the maturing Postgres to provide some kind of solution for some context so that user can scratch their
itches.
Regards
Takayuki Tsunakawa