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From Vivek Krishna <vivekris...@gmail.com>
Subject Re: File formats in Hadoop
Date Tue, 22 Mar 2011 15:58:58 GMT
http://nosql.mypopescu.com/post/3220921756/hbase-internals-hfile-explained
might help.

Viv



On Tue, Mar 22, 2011 at 11:43 AM, Weishung Chung <weishung@gmail.com> wrote:

> 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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