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From Weishung Chung <weish...@gmail.com>
Subject Re: File formats in Hadoop
Date Tue, 22 Mar 2011 15:43:55 GMT
My fellow superb hbase experts,

Looking at the HFile specs and have some questions.
How is a particular table cell in a HBase table being represented in the
HFile? Does the key of the key value pair represent the rowkey+column
family:qualifier+timestamp and the value represent the corresponding cell
value? If so, to read a row, multiple key/value pair reads have to be done?

Thank you :)


On Tue, Mar 22, 2011 at 9:09 AM, Weishung Chung <weishung@gmail.com> wrote:

> Thank you, I will definitely take a look. Also, the TFile spec below helps
> me to understand more,
> what an exciting work !
>
>
> https://issues.apache.org/jira/secure/attachment/12396286/TFile+Specification+20081217.pdf
>
> <https://issues.apache.org/jira/secure/attachment/12396286/TFile+Specification+20081217.pdf>
> On Mon, Mar 21, 2011 at 11:41 AM, Doug Cutting <cutting@apache.org> wrote:
>
>> On 03/19/2011 09:01 AM, Weishung Chung wrote:
>> > I am browsing through the hadoop.io package and was wondering what
>> other
>> > file formats are available in hadoop other than SequenceFile and TFile?
>> > Is all data written through hadoop including those from hbase saved in
>> the
>> > above formats? It seems like SequenceFile is in key value pair format.
>>
>> Avro includes a file format that works with Hadoop.
>>
>>
>> http://avro.apache.org/docs/current/api/java/org/apache/avro/mapred/package-summary.html
>>
>> Doug
>>
>
>

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