> One use of replication can be point-in-time recovery. The log of
> replication messages can be played back against a nightly backup to
> restore the system to the current state. It would be nice to hit both
> of these at the same time.
WAL currently has all that is needed for full instance master slave replication.
Imho it would be a shame to add yet another txlog that is only used for
replication. Imho if the current WAL misses some info that would be needed
for partial and master-master replication, then the current WAL should be
extended to contain such info.
What instantly comes to mind is the old primary key value.
Since I guess we want partial replication we need a log sniffer anyway,
that extracts only what is needed for a specific target replicate.
Imho most efficiently replicating "delete from atab;" or other single statements
that affect many rows should not be a main issue in replication design.
Andreas