Jie Li 2013-01-05, 03:46
Can Hive implement the aggregation as a Map-only job? As we know the
data may be pre-partitioned via PARTITION-BY or CLUSTERED-BY, so we
don't need the reduce phase to repartition the data.
The Bucket Join seems to take advantage of the buckets for joins, so I
wonder if there is some similar optimization for aggregations.