Hi,
based on roadmap [1], we would like to define and implement a full set
of (unified) stream-stream joins. That would include:
- joins (left, right, full outer) on global window with "immediate
trigger"
- joins with different windowing functions on left and right side
The approach would be to define these operations in a natural way, so
that the definition is aligned with how current joins work (same
windows, cartesian product of values with same keys, output timestamp
projected to the end of window, etc.). Because this should be a generic
approach, this effort should probably be part of join library, that can
the be reused by other components, too (e.g. SQL).
The question is - is (or was) there any effort that we can build upon?
Or should this be designed from scratch?
Jan
[1] https://beam.apache.org/roadmap/euphoria/
