> > >>> Recovery can occur with/without same setting of wal_checksum, to
avoid
> > >>> complications from crashes immediately after turning GUC on.
> > >>
> > >> Surely not. Otherwise even the "on" setting is not really a
defense.
> >
> > > Only when the CRC is exactly zero, which happens very very rarely.
> >
> > "It works most of the time" doesn't exactly satisfy me. What's the
Agreed
> > use-case for changing the variable on the fly anyway? Seems a
better
> > solution is just to lock down the setting at postmaster start.
I guess that the use case is more for a WAL based replicate, that
has/wants a different setting. Maybe we want a WAL entry for the change,
or force a log switch (so you can interrupt the replicate, change it's
setting
and proceed with the next log) ?
Maybe a 3rd mode for replicates that ignores 0 CRC's ?
Andreas