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Posted to user@hadoop.apache.org by unmesha sreeveni <un...@gmail.com> on 2014/01/10 07:36:58 UTC
Find max and min of a column in a csvfile
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/
Re: Find max and min of a column in a csvfile
Posted by unmesha sreeveni <un...@gmail.com>.
Thanks Jiayu and John Hancock.
Showered a very nice hint for me.
John that was a really gud link you provided. But i dnt know Pig. I am
using java.
Is there any java related document.
like :
http://packtlib.packtpub.com/library/hadoop-mapreduce-cookbook/ch06lvl1sec66#
On Sat, Jan 11, 2014 at 6:14 PM, John Hancock <jh...@gmail.com>wrote:
> 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 <ji...@gmail.com> 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 <unmeshabiju@gmail.com
>> > 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
>>
>>
>
--
*Thanks & Regards*
Unmesha Sreeveni U.B
Junior Developer
http://www.unmeshasreeveni.blogspot.in/
Re: Find max and min of a column in a csvfile
Posted by unmesha sreeveni <un...@gmail.com>.
Thanks Jiayu and John Hancock.
Showered a very nice hint for me.
John that was a really gud link you provided. But i dnt know Pig. I am
using java.
Is there any java related document.
like :
http://packtlib.packtpub.com/library/hadoop-mapreduce-cookbook/ch06lvl1sec66#
On Sat, Jan 11, 2014 at 6:14 PM, John Hancock <jh...@gmail.com>wrote:
> 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 <ji...@gmail.com> 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 <unmeshabiju@gmail.com
>> > 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
>>
>>
>
--
*Thanks & Regards*
Unmesha Sreeveni U.B
Junior Developer
http://www.unmeshasreeveni.blogspot.in/
Re: Find max and min of a column in a csvfile
Posted by unmesha sreeveni <un...@gmail.com>.
Thanks Jiayu and John Hancock.
Showered a very nice hint for me.
John that was a really gud link you provided. But i dnt know Pig. I am
using java.
Is there any java related document.
like :
http://packtlib.packtpub.com/library/hadoop-mapreduce-cookbook/ch06lvl1sec66#
On Sat, Jan 11, 2014 at 6:14 PM, John Hancock <jh...@gmail.com>wrote:
> 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 <ji...@gmail.com> 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 <unmeshabiju@gmail.com
>> > 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
>>
>>
>
--
*Thanks & Regards*
Unmesha Sreeveni U.B
Junior Developer
http://www.unmeshasreeveni.blogspot.in/
Re: Find max and min of a column in a csvfile
Posted by unmesha sreeveni <un...@gmail.com>.
Thanks Jiayu and John Hancock.
Showered a very nice hint for me.
John that was a really gud link you provided. But i dnt know Pig. I am
using java.
Is there any java related document.
like :
http://packtlib.packtpub.com/library/hadoop-mapreduce-cookbook/ch06lvl1sec66#
On Sat, Jan 11, 2014 at 6:14 PM, John Hancock <jh...@gmail.com>wrote:
> 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 <ji...@gmail.com> 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 <unmeshabiju@gmail.com
>> > 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
>>
>>
>
--
*Thanks & Regards*
Unmesha Sreeveni U.B
Junior Developer
http://www.unmeshasreeveni.blogspot.in/
Re: Find max and min of a column in a csvfile
Posted by John Hancock <jh...@gmail.com>.
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 <ji...@gmail.com> 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 <un...@gmail.com>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
>
>
Re: Find max and min of a column in a csvfile
Posted by John Hancock <jh...@gmail.com>.
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 <ji...@gmail.com> 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 <un...@gmail.com>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
>
>
Re: Find max and min of a column in a csvfile
Posted by John Hancock <jh...@gmail.com>.
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 <ji...@gmail.com> 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 <un...@gmail.com>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
>
>
Re: Find max and min of a column in a csvfile
Posted by John Hancock <jh...@gmail.com>.
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 <ji...@gmail.com> 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 <un...@gmail.com>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
>
>
Re: Find max and min of a column in a csvfile
Posted by Jiayu Ji <ji...@gmail.com>.
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 <un...@gmail.com>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
Re: Find max and min of a column in a csvfile
Posted by Jiayu Ji <ji...@gmail.com>.
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 <un...@gmail.com>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
Re: Find max and min of a column in a csvfile
Posted by Jiayu Ji <ji...@gmail.com>.
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 <un...@gmail.com>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
Re: Find max and min of a column in a csvfile
Posted by Jiayu Ji <ji...@gmail.com>.
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 <un...@gmail.com>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