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HBase, mail # user - Disk Seeks and Column families


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Praveen Sripati 2012-01-21, 07:08
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Andrey Stepachev 2012-01-21, 12:47
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Doug Meil 2012-01-21, 13:52
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Doug Meil 2012-01-21, 15:16
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Andrey Stepachev 2012-01-21, 18:58
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Re: Disk Seeks and Column families
yuzhihong@... 2012-01-21, 15:33
Have you considered using AggregationProtocol to perform aggregation ?

Thanks

On Jan 20, 2012, at 11:08 PM, Praveen Sripati <[EMAIL PROTECTED]> wrote:

> Hi,
>
> 1) According to the this url (1), HBase performs well for two or three
> column families. Why is it so?
>
> 2) Dump of a HFile, looks like below. The contents of a row stay together
> like a regular row-oriented database. If the column family has 100 column
> family qualifiers and is dense then the data for a particular column family
> qualifier is spread wide. If I want to do an aggregation on a particular
> column identifier, the disk seeks doesn't seems to be much better than a
> regular row-oriented database.
>
> Please correct me if I am wrong.
>
> K: row-550/colfam1:50/1309813948188/Put/vlen=2 V: 50
> K: row-550/colfam1:50/1309812287166/Put/vlen=2 V: 50
> K: row-551/colfam1:51/1309813948222/Put/vlen=2 V: 51
> K: row-551/colfam1:51/1309812287200/Put/vlen=2 V: 51
> K: row-552/colfam1:52/1309813948256/Put/vlen=2 V: 52
>
> (1) - http://hbase.apache.org/book/number.of.cfs.html
>
> Thanks,
> Praveen
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Praveen Sripati 2012-01-21, 17:49
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Doug Meil 2012-01-21, 18:06
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M. C. Srivas 2012-01-22, 06:32
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Praveen Sripati 2012-01-24, 06:15
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Andrey Stepachev 2012-01-24, 06:51
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Andrey Stepachev 2012-01-24, 06:52
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Jason Frantz 2012-01-24, 09:30