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HDFS, mail # user - Re: Find max and min of a column in a csvfile


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Re: Find max and min of a column in a csvfile
John Hancock 2014-01-11, 12:44
Unmesha,

You may want to write your own mapper and reducer for the purpose of
learning more about map-reduce programming techniques.

However, the Pig documentation also discusses aggregate functions such as
max() which may save you some time:

http://pig.apache.org/docs/r0.12.0/udf.html
-John
On Fri, Jan 10, 2014 at 12:23 PM, Jiayu Ji <[EMAIL PROTECTED]> wrote:

> if you are doing with only one column, then I think the key/value pair
> could be Null and number( elements) . If you are doing more than one
> column, then column name and numbers.
>
>
> On Fri, Jan 10, 2014 at 12:36 AM, unmesha sreeveni <[EMAIL PROTECTED]>wrote:
>
>>
>> Need help
>> How to find the maximum element and min element of a col in a csv file
>> .What will be the mapper output.
>>
>> --
>> *Thanks & Regards*
>>
>> Unmesha Sreeveni U.B
>> Junior Developer
>>
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Jiayu (James) Ji,
>
> Cell: (312)823-7393
>
>