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From Zheng Shao <zsh...@gmail.com>
Subject Re: intermediate data written to the disk?
Date Wed, 03 Feb 2010 21:39:41 GMT
If the join key is the same, you can use "unique join" to make sure
it's done in a single map-reduce job.


Zheng

On Wed, Feb 3, 2010 at 1:25 AM, bharath v
<bharathvissapragada1990@gmail.com> wrote:
> Hi ,
>
> I have a small doubt in how hive handles queries containing join of more
> than 2 tables .
>
> Suppose we have 3 tables A,B,C .. and the plan isĀ  "((AB)C)" ..
> We can join A,B in a map reduce job and join the resultant table with "C". I
> have a doubt whether the result of "AB" is stored to disk before joining
> with C or is it streamed directly to join with C (I don't know how , just a
> guess) .
>
>
> Any help is appreciated ,
>
> Thanks



-- 
Yours,
Zheng

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