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From nagarjuna kanamarlapudi <nagarjuna.kanamarlap...@gmail.com>
Subject Re: Execution of udf
Date Fri, 18 Jan 2013 14:57:16 GMT
No but the query execution shows a reducer running .. And infant I feel
that reduce phase can be there

On Friday, January 18, 2013, Dean Wampler wrote:

> There is no reduce phase needed in this query.
>
> On Fri, Jan 18, 2013 at 6:59 AM, nagarjuna kanamarlapudi <
> nagarjuna.kanamarlapudi@gmail.com <javascript:_e({}, 'cvml',
> 'nagarjuna.kanamarlapudi@gmail.com');>> wrote:
>
>> Hi,
>>
>> Select col1,myudf(col2,col3) from table1;
>>
>>
>> In what phase if map reduce an udf is executed.
>>
>> In the very beginning, I assumed that hive will be joining two tables.,
>> getting the required columns and then applies udf on columns specified
>> I.e., essentially on reducer phase . But later on I realised that I was
>> wrong.
>>
>> Is there any specific parameter which suggests hive to call udf at
>> reducer phase rather than at Mapper phase.
>>
>>
>> Regards,
>> Nagarjuna
>>
>>
>> --
>> Sent from iPhone
>>
>
>
>
> --
> *Dean Wampler, Ph.D.*
> thinkbiganalytics.com
> +1-312-339-1330
>
>

-- 
Sent from iPhone

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