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From Jeff Zhang <zjf...@gmail.com>
Subject Re: mapreduce from cassandra to cassandra
Date Tue, 18 May 2010 09:39:30 GMT
BTW, maybe we should create an issue on jira for this problem if the
Cassandra committee think it is necessary.



On Tue, May 18, 2010 at 5:30 PM, Jeff Zhang <zjffdu@gmail.com> wrote:
> reuse is not possible, but I think it won't hard for cassandra to
> implement a ColumnFamilyOutputFormat. In my opinion, the
> ColumnFamilyOutputFormat should be easier to implement than
> ColumnFamilyInputFormat, because you don't need to think about split
> in the implementation of OutputFormat.
>
>
>
>
>
> On Tue, May 18, 2010 at 5:22 PM, Ran Tavory <rantav@gmail.com> wrote:
>> hbase - yes. But is that reusable for cassandra?
>>
>> On Tue, May 18, 2010 at 12:17 PM, Jeff Zhang <zjffdu@gmail.com> wrote:
>>>
>>> I believe it is possible to write result back to cassandra. If I
>>> remember correctly, HBase has both InputFormat and OutputFormat for
>>> hadoop.
>>>
>>>
>>>
>>>
>>> On Tue, May 18, 2010 at 5:08 PM, Ran Tavory <rantav@gmail.com> wrote:
>>> > In the wordcount example the process reads from cassandra and the result
>>> > is
>>> > written to a local file at /tmp/word_count*
>>> > Is it possible to read from cassandra and write the result back to
>>> > cassandra
>>> > to a specified cf/row/column?
>>> > I see that there exists a ColumnFamilyInputFormat but not
>>> > ColumnFamilyOutputFormat or something like that
>>> >
>>> > (in http://svn.apache.org/repos/asf/cassandra/trunk/src/java/org/apache/cassandra/hadoop/)
>>> > My knowledge about hadoop and mr is pretty basic so maybe I'm missing
>>> > something simple, lmk, thanks!
>>>
>>>
>>>
>>> --
>>> Best Regards
>>>
>>> Jeff Zhang
>>
>>
>
>
>
> --
> Best Regards
>
> Jeff Zhang
>



-- 
Best Regards

Jeff Zhang

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