Hi, I am using a FileBasedSink (AvroIO.write) on an unbounded stream (withWindowedWrites, hourly windows, numShards=4).
I would like to partition the stream by some key in the element, so that all elements with the same key will get processed by the same shard writer, and therefore written to the same file. Is there a way to do this? Note that in my stream the number of keys is very large (most elements have a unique key, while a few elements share a key). Thanks, Josh