On Oct 22, 2015 23:38, "Tom Lane" <t...@sss.pgh.pa.us> wrote: > > Jim Nasby <jim.na...@bluetreble.com> writes: > > ISTM it should be possible to avoid sending full page writes to a > > streaming replica once the replica has reached a consistent state. I > > assume that the replica would still need to write full pages to it's > > disk in case of a crash, but the sender could insert special WAL records > > to tell it when to do so, instead of sending the full page image. > > Presumably this would be a big win for replication over a WAN. > > How are you going to make that work without LSNs in the WAL received by > the replica diverging from those in the master's WAL? >
We could in theory send a "this would be been a fpi but it's skipped" record which would only exist in streaming and just make the standby write a noop of some kind? It would still be on the standby but it would at least not consume the bandwidth. Just skip sending the actual contents of the fpi. /Magnus
