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MapReduce, mail # dev - Reduce output is strange


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Re: Reduce output is strange
Owen O'Malley 2012-04-03, 15:29
On Tue, Apr 3, 2012 at 8:25 AM, Pedro Costa <[EMAIL PROTECTED]> wrote:
> What I want to ask is:
>
> - how do I read the values from sequence files that are block, or record
> compressed, or uncompressed?

You use the SequenceFile.Reader class.

> - how do I know if the sequence file is block compressed, record
> compressed, or uncompressed?

You use the SequenceFile.Reader class.

>
> - how do I know if it's a sequence file or a Textfile?

SequenceFile's always have "SEQ" followed by the version in the first 4 bytes.

-- Owen