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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).


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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