Hello
> > But what if someone sets wal_level=none, performs some data > > modifications, sets wal_level=archive and after dome more processing > > decides to restore from a backup that was taken before the cluster was set > to wal_level=none? > > Then they would end up with a corrupted database, right? > > > > I think the least this patch needs is that starting with > > wal_level=none emits a WAL record that will make recovery fail. > > I just realized that changing "wal_level" will cause a WAL record anyway. > Besides, the situation is not much different from changing to "wal_level = > minimal". > So as long as PostgreSQL refuses to start after a crash, we should be good. > > Sorry for the noise, and I am beginning to think that this is actually a > useful > feature. No problem at all. Probably, for some developers, was the name "none" confusing ? Also, thank you for your pointing out my lack of explanation in the documents of the replication in the previous e-mail. Best, Takamichi Osumi