Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive >> mail # user >> Map-only aggregation


Copy link to this message
-
Map-only aggregation
Hi all,

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.

Thanks,
Jie