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From Jean-Daniel Cryans <jdcry...@apache.org>
Subject Re: Get operation in HBase Map-Reduce methods
Date Tue, 20 Apr 2010 08:15:52 GMT
What are the numbers like? Is it 1k rows you need to process? 1M? 10B?
Your question is more about scaling (or the need to).

J-D

On Tue, Apr 20, 2010 at 8:39 AM, Andrey <atimerbaev@gmx.net> wrote:
> Dear All,
>
> Assumed, I've got a list of rowIDs of a HBase table. I want to get each row by
> its rowID, do some operations with its values, and store the results somewhere
> subsequently. Is there a good way to do this in a Map-Reduce manner?
>
> As far as I understand, a mapper usually takes a Scan to form inputs. It is
> quite possible to create such a Scan, which contains a lot of RowFilters to be
> EQUAL to a particular <rowId>. Such a strategy will work for sure, however is
> inefficient, since each filter will be tried to match to each found row.
>
> So, is there a good Map-Reduce praxis for such kind of situations? (E.g. to make
> a Get operation inside a map() method.) If yes, could you kindly point to a good
> code example?
>
> Thank you in advance.
>
>

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