I wasn't clear: this has worked for a long time. I wasn't suggesting a new feature. I didn't look up the exact incantation.
Kenn On Thu, Nov 21, 2019, 14:49 Robert Bradshaw <[email protected]> wrote: > On Thu, Nov 21, 2019 at 2:46 PM Reuven Lax <[email protected]> wrote: > > > > That is racy. It could also be that the side input hasn't been computed > yet but will be available in a second. > > It's no more racy than any other side input lookup (as we still > respect not declaring a window is empty until the watermark asserts > so). > > > On Thu, Nov 21, 2019 at 2:37 PM Kenneth Knowles <[email protected]> wrote: > >> > >> It can work in pull mode when it is a side input, via > Combine.globally().asSingletonView(). Then the default is produced when the > side input is requested and there is no data found. > >> > >> Kenn > >> > >> On Thu, Nov 21, 2019 at 10:32 AM Reuven Lax <[email protected]> wrote: > >>> > >>> In particular, since windows can be data based (e.g. session windows) > the set of windows is not always knowable in advance. > >>> > >>> On Thu, Nov 21, 2019 at 10:29 AM Robert Bradshaw <[email protected]> > wrote: > >>>> > >>>> The semantics are a bit undefined--the sane extension of the model to > >>>> support this is that the default value would show up in every window > >>>> (otherwise which window would the default value belong to), but we > >>>> don't have support for enumerating windows (or truncating infinite > >>>> collections in batch mode). > >>>> > >>>> On Thu, Nov 21, 2019 at 4:55 AM Robin Qiu <[email protected]> wrote: > >>>> > > >>>> > Hi all, > >>>> > > >>>> > When I run a Combine.globally() transform with a default value set, > on a PCollection windowed by a FixedWindow, I got this error message: > >>>> > > >>>> > java.lang.IllegalStateException: Default values are not supported > in Combine.globally() if the input PCollection is not windowed by > GlobalWindows ... > >>>> > (from here) > >>>> > > >>>> > Is this unsupported because it is not implemented yet, or is this a > design decision to not support default values with windows other than > GlobalWIndow (e.g. because the semantics is not well defined)? Where can I > learn more about this? > >>>> > > >>>> > Best, > >>>> > Robin >
