Hi,
You probably need to use secondary sort (based on TextPair key) and
string concatenation function (like StringBuffer) to do this. I once
had a talk on Open Cloud Science workshop about this (also see my
previous post in this newsgroup)
Best,
Shi
On 9/20/2011 10:38 AM, Daniel Yehdego wrote:
Hi Ayon,
any idea on my previous question?
Regards,
Daniel T. Yehdego
Computational Science Program
University of Texas at El Paso, UTEP
dtyehd...@miners.utep.edu
From: dtyehd...@miners.utep.edu
To: common-user@hadoop.apache.org
Subject: RE: Reducer to concatenate string values
Date: Tue, 20 Sep 2011 06:06:22 +0000
Hi Ayon,
I am using a C executable as my mapper (streaming), but I am not sure how to
use a reducer that concatenates the values from a mapper in order.
Regards,
Daniel T. Yehdego
Computational Science Program
University of Texas at El Paso, UTEP
dtyehd...@miners.utep.edu
Date: Mon, 19 Sep 2011 22:54:46 -0700
From: ayonsi...@yahoo.com
Subject: Re: Reducer to concatenate string values
To: common-user@hadoop.apache.org
What are you using for your map/reduce? Streaming/Java/Pig/Hive?
-Ayon
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Also check out my Blog for answers to commonly asked questions.
________________________________
From: Daniel Yehdego<dtyehd...@miners.utep.edu>
To: common-user@hadoop.apache.org
Sent: Monday, September 19, 2011 10:43 PM
Subject: Reducer to concatenate string values
Good evening,
I have a certain value output from a mapper and I want to concatenate the
string outputs using a Reducer (one reducer).But the order of the concatenated
string values is not in order. How can I use a reducer that receives a value
from a mapper output and concatenate the strings in order. waiting your
response and thanks in advance.
Regards,
Daniel T. Yehdego
Computational Science Program
University of Texas at El Paso, UTEP
dtyehd...@miners.utep.edu
