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From "Sandy Ryza (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (MAPREDUCE-5457) Add a KeyOnlyTextOutputReader to enable streaming to write out text files without separators
Date Fri, 23 Aug 2013 00:51:57 GMT

     [ https://issues.apache.org/jira/browse/MAPREDUCE-5457?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Sandy Ryza updated MAPREDUCE-5457:
----------------------------------

    Description: 
MR jobs sometimes want to just output lines of text, not key/value pairs.  TextOutputFormat
handles this by, if a null value is given, outputting only the key with no separator.  Streaming
jobs are unable to take advantage of this, because they can't output null values.  A text
output format reader takes each line as a key and outputs NullWritables for values would allow
streaming jobs to output lines of text. 



  was:
MR jobs sometimes want to just output lines of text, not key/value pairs.  TextOutputFormat
handles this by, if a null value is given, outputting only the key with no separator.  Streaming
jobs are unable to take advantage of this, because they can't output null values.  A text
output format that ignores values and only outputs keys would allow streaming jobs to output
lines of text. 



    
> Add a KeyOnlyTextOutputReader to enable streaming to write out text files without separators
> --------------------------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-5457
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5457
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>    Affects Versions: 2.1.0-beta
>            Reporter: Sandy Ryza
>
> MR jobs sometimes want to just output lines of text, not key/value pairs.  TextOutputFormat
handles this by, if a null value is given, outputting only the key with no separator.  Streaming
jobs are unable to take advantage of this, because they can't output null values.  A text
output format reader takes each line as a key and outputs NullWritables for values would allow
streaming jobs to output lines of text. 

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