Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
MapReduce >> mail # user >> Re: How to output according to the key in reducer?


Copy link to this message
-
Re: How to output according to the key in reducer?
Hi,

Can you see if the MultipleOutputs class can work for you ?

(
http://hadoop.apache.org/docs/r1.0.3/api/org/apache/hadoop/mapreduce/lib/output/MultipleOutputs.html
)

On Mon, Sep 17, 2012 at 12:46 PM, Jason Yang <[EMAIL PROTECTED]>wrote:

> Hi, all
>
> I was wondering how to write all the input with the same key to a single
> file in the reducer ?
>
> say, I got some intermediate outputs from mappers like that:
> key     value
> --------------------
> 1   annie
> 2   Jason
> 1   andy
> 2   Joey
> 1   andrew
> ...
>
> and I would like write all the intermediate outputs with key 1 to file
> "ID_1.dat", and all the intermediate outputs with key 2 to file "ID_2.data".
>
> how could I achieve that?
>
> --
> YANG, Lin
>
>
+
feng lu 2012-09-17, 08:47
+
Jason Yang 2012-09-17, 09:23