dynamic partition inserts in hive 13

["Gajendran, Vishnu" <vi...@amazon.com>]

Hello,

I am seeing a difference between hive 11 and hive 13 when inserting to a table with dynamic partition.

In Hive 11, when I set hive.merge.mapfiles=false before doing a dynamic partition insert, I see number of files (generated my each mapper) in the specified hdfs location as expected. But, in Hive 13, when I set hive.merge.mapfiles=false, I just see one file in specified hdfs location for the same query. I think hive is not honoring the hive.merge.mapfiles parameter and it merged all the mapper outputs to a single file.

In Hive 11, 19 mappers were executed for the dynamic partition insert task. But in Hive 13, 19 mappers and 2 reducers were executed.

When I checked the query plan for hive 11, there is only a map operator task for dynamic partition insert. But, in hive 13, I see both map operator and reduce operator task.

Is there any changes in hive 13 regarding dymamic partition inserts? Any comments on this issue is greatly appreciated.

Thanks,
vishnu