You are viewing a plain text version of this content. The canonical link for it is here.

Posted to user@hive.apache.org by Edson Ramiro <er...@gmail.com> on 2016/08/08 18:59:12 UTC

does Hive implement any Combiner by default?

hi all,

I'm executing TPC-H on Hive 2.0.1, using Yarn 2.7, and I'm wondering if
Hive implements any Combiner by default? If so, how do I enable it?

I am asking this because I checked the values of COMBINE_INPUT_RECORDS and
COMBINE_OUTPUT_RECORDS and they are always zero.

Thanks in advance,

      Edson Ramiro

Re: does Hive implement any Combiner by default?

Posted by Edson Ramiro <er...@gmail.com>.

In this case, are there counters related to map-side aggregation ?



      Edson Ramiro

On Mon, Aug 8, 2016 at 4:00 PM, Edward Capriolo <ed...@gmail.com>
wrote:

> Hive uses map side aggregation instead of combiners
>
> http://dev.bizo.com/2013/02/map-side-aggregations-in-apache-hive.html
>
> On Mon, Aug 8, 2016 at 2:59 PM, Edson Ramiro <er...@gmail.com> wrote:
>
>> hi all,
>>
>> I'm executing TPC-H on Hive 2.0.1, using Yarn 2.7, and I'm wondering if
>> Hive implements any Combiner by default? If so, how do I enable it?
>>
>> I am asking this because I checked the values of COMBINE_INPUT_RECORDS
>> and COMBINE_OUTPUT_RECORDS and they are always zero.
>>
>> Thanks in advance,
>>
>>       Edson Ramiro
>>
>
>

Re: does Hive implement any Combiner by default?

Posted by Edward Capriolo <ed...@gmail.com>.

Hive uses map side aggregation instead of combiners

http://dev.bizo.com/2013/02/map-side-aggregations-in-apache-hive.html

On Mon, Aug 8, 2016 at 2:59 PM, Edson Ramiro <er...@gmail.com> wrote:

> hi all,
>
> I'm executing TPC-H on Hive 2.0.1, using Yarn 2.7, and I'm wondering if
> Hive implements any Combiner by default? If so, how do I enable it?
>
> I am asking this because I checked the values of COMBINE_INPUT_RECORDS and
> COMBINE_OUTPUT_RECORDS and they are always zero.
>
> Thanks in advance,
>
>       Edson Ramiro
>