Re: Proposal for 9.1: WAL streaming from WAL buffers

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> If it's unsafe to send written but unflushed WAL to the standby, then
> for the same reasons we can't send unwritten WAL either.
[...]
> Having said that, I do think we urgently need some high-level design
> discussion on how sync rep is actually going to handle this issue

Stop me if I'm all wrong already, but I though we said that we should
handle this case by decoupling what we can send to the standby and what
it can apply. We could do this by sending the current WAL fsync'ed
position on the master in the WAL sender protocol, either in the WAL
itself or as out-of-bound messages, I guess.

Now, this can be made safe, how to make it fast (low-latency) is yet to
be addressed.

Regards,
--
dim