On Wed, Aug 26, 2020 at 12:54 PM tsunakawa.takay@fujitsu.com
<tsunakawa.takay@fujitsu.com> wrote:
>
>
> Following this idea, what do you think about adding a new value "none" to wal_level, where no WAL is generated? The
settingof wal_level is recorded in pg_control. The startup process can see the value and reject recovery after
abnormalshutdown, emitting a message similar to MySQL's.
>
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.
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).
--
With Regards,
Amit Kapila.