Hi team, I was thinking of merging spark-3 branch into master, also per the discussion before we could make spark-2 and spark-3 coexisted into 2 different sub-modules. With this, one build could generate both spark-2 and spark-3 runtime jars, user could pick either at preference.
One concern is that they share lots of common code in read/write path, this will increase the maintenance overhead to keep consistency of two copies. So I'd like to hear your thoughts, any suggestions on it? Thanks Saisai
