[BEAM-638] Add sink transform to write bounded data per window, pane, [and key] even when PCollection is unbounded

• Type: New Feature
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: sdk-java-core
• Labels: Done
• Assignee: Davor Bonaci
• Reporter: Jean-Baptiste Onofré
• Created: 19/Sep/16 15:33
• Updated: 06/Oct/20 21:55
• Resolved: 07/May/17 15:31

Description

Today, if the pipeline source is unbounded, and the sink expects a bounded collection, there's no way to use a single pipeline. Even a window creates a chunk on the unbounded PCollection, but the "sub" PCollection is still unbounded.
It would be helpful for users to have a Window function that create a bounded PCollection (on the window) from an unbounded PCollection coming from the source.