On Thu, 13 Apr 2023 at 14:31, Alexander Saydakov <saydakov@xxxxxxxxxxxx> wrote: > 1. I wonder if there is a clean separation between the phases: once partial aggregation is done only combining is done after that (state transition function never receives results of combining). Currently the transfn won't be called again on a state that has had the combinefn called on it. I can't think of a future reason that we might change that. My imagination might be lacking, however. > 2. Can a combiner output also go through serial-deserial before hitting another combiner or finalizer? Not currently. However, I *can* think of reasons why that might change in the future. If we wanted to accept partially aggregated results from foreign servers and then combine them locally then, if those foreign servers did parallel aggregation, the foreign server's combined states would need to be serialised before sending over the network. It feels like just a matter of time before we grow the ability to do that. Lots of work has been done on foreign data wrappers in the past few years. It feels like it has tailed off a bit, but I wouldn't be surprised if we had the ability to do that in the next few years. David
