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Posted to mapreduce-user@hadoop.apache.org by Yin Lou <yi...@gmail.com> on 2010/10/31 19:32:49 UTC

MultipleOutputFormat

Hi,

I wonder how MultipleOutputFormat works.  Suppose my reducer <k1, list(v1)>
-> <k2, v2>. Does the method "generateFileNameForKeyValue" depends on k2 or
k1? Is there anyway to generate file name based on k1?

Thanks,
Yin

Re: MultipleOutputFormat

Posted by Ted Yu <yu...@gmail.com>.

>From Java doc:
   * Generate the file output file name based on the given key and the leaf
file
   * name. The default behavior is that the file name does not depend on the
   * key.

You can extend MultipleTextOutputFormat or MultipleSequenceFileOutputFormat
to override the default naming.

On Sun, Oct 31, 2010 at 11:32 AM, Yin Lou <yi...@gmail.com> wrote:

> Hi,
>
> I wonder how MultipleOutputFormat works.  Suppose my reducer <k1, list(v1)>
> -> <k2, v2>. Does the method "generateFileNameForKeyValue" depends on k2 or
> k1? Is there anyway to generate file name based on k1?
>
> Thanks,
> Yin
>