Hi Prasanth,
Thanks a lot for your quick response.
From: Prasanth Jayachandran [pjayachand...@hortonworks.com]
Sent: Tuesday, July 22, 2014 11:28 AM
To: u...@hive.apache.org
Cc: dev@hive.apache.org
Subject: Re: hive 13: dynamic partition inserts
Hi Vishnu
Yes. There is change in the way dynamic partitions are inserted in hive 13. The
new dynamic partitioning is highly scalable and uses very less memory. Here is
the related JIRA https://issues.apache.org/jira/browse/HIVE-6455.
Setting hive.optimize.sort.dynamic.partition to false will fallback to old
way of insertion. If your destination table uses columnar formats like ORC,
Parquet etc. then it makes sense leave the optimization ON, as columnar formats
needs some buffer space for each column before flushing to disk. Buffer space
(runtime memory) will quickly shoot up when there are lots of partition column
values and columns. HIVE-6455 addresses this issue.
Thanks
Prasanth Jayachandran
On Jul 22, 2014, at 10:51 AM, Gajendran, Vishnu
vis...@amazon.commailto:vis...@amazon.com wrote:
adding u...@hive.apache.orgmailto:u...@hive.apache.org for wider audience
From: Gajendran, Vishnu
Sent: Tuesday, July 22, 2014 10:42 AM
To: dev@hive.apache.orgmailto:dev@hive.apache.org
Subject: hive 13: dynamic partition inserts
Hello,
I am seeing a difference between hive 11 and hive 13 when inserting to a table
with dynamic partitions.
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
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