Thanks! Shen
On Thu, May 11, 2017 at 2:29 PM, Reuven Lax <[email protected]> wrote: > We sometimes see this when users generate flattens with a for loop (e.g. > over input sources for a side input). Sometimes there is no input, and the > flatten is empty. > > > On Thu, May 11, 2017 at 11:24 AM, Shen Li <[email protected]> wrote: > > > Hi, > > > > The FlattenTest enforces that Flatten transform can handle empty input. > Is > > there any use case for this feature? > > > > https://github.com/apache/beam/blob/release-2.0.0/sdks/ > > java/core/src/test/java/org/apache/beam/sdk/transforms/ > > FlattenTest.java#L128 > > > > How should a runner translate an empty Flatten? Should it be a > > BoundedSource that emits a single watermark of value > > BoundedWindow.TIMESTAMP_MAX_VALUE? > > > > Thanks, > > > > Shen > > >
