HIVE-2329 RS dedup optimization shoud be avoided in some cases
Review Request #1313 - Created Aug. 8, 2011 and submitted
If map aggregation is set to false, DISTRIBUTED BY followed by GROUP BY with same key fails in runtime. ReduceSinkDeDuplication optimization should be avoid if child of child RS is GBY.
test added : reduce_deduplicate_exclude_gby.q