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HDFS, mail # user - How can I record some position of context in Reduce()?


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Re: How can I record some position of context in Reduce()?
Azuryy Yu 2013-03-13, 14:36
you want a n:n join or 1:n join?
On Mar 13, 2013 10:51 AM, "Roth Effy" <[EMAIL PROTECTED]> wrote:

> I want to join two table data in reducer.So I need to find the start of
> the table.
> someone said the DataJoinReducerBase can help me,isn't it?
>
>
> 2013/3/13 Azuryy Yu <[EMAIL PROTECTED]>
>
>> you cannot use RecordReader in Reducer.
>>
>> what's the mean of you want get the record position? I cannot understand,
>> can you give a simple example?
>>
>>
>> On Wed, Mar 13, 2013 at 9:56 AM, Roth Effy <[EMAIL PROTECTED]> wrote:
>>
>>> sorry,I still can't understand how to use recordreader in the
>>> reduce(),because the input is a RawKeyValueIterator in the class
>>> reducecontext.so,I'm confused.
>>> anyway,thank you.
>>>
>>>
>>> 2013/3/12 samir das mohapatra <[EMAIL PROTECTED]>
>>>
>>>> Through the RecordReader and FileStatus you can get it.
>>>>
>>>>
>>>> On Tue, Mar 12, 2013 at 4:08 PM, Roth Effy <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> Hi,everyone,
>>>>> I want to join the k-v pairs in Reduce(),but how to get the record
>>>>> position?
>>>>> Now,what I thought is to save the context status,but class Context
>>>>> doesn't implement a clone construct method.
>>>>>
>>>>> Any help will be appreciated.
>>>>> Thank you very much.
>>>>>
>>>>
>>>>
>>>
>>
>