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From Harsh J <ha...@cloudera.com>
Subject Re: Anyway to load certain Key/Value pair fast?
Date Wed, 13 Feb 2013 05:29:40 GMT
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On Wed, Feb 13, 2013 at 10:54 AM, William Kang <weliam.cloud@gmail.com> wrote:
> Hi All,
> I am trying to figure out a good solution for such a scenario as following.
> 1. I have a 2T file (let's call it A), filled by key/value pairs,
> which is stored in the HDFS with the default 64M block size. In A,
> each key is less than 1K and each value is about 20M.
> 2. Occasionally, I will run analysis by using a different type of data
> (usually less than 10G, and let's call it B) and do look-up table
> alike operations by using the values in A. B resides in HDFS as well.
> 3. This analysis would require loading only a small number of values
> from A (usually less than 1000 of them) into the memory for fast
> look-up against the data in B. The way B finds the few values in A is
> by looking up for the key in A.
> Is there an efficient way to do this?
> I was thinking if I could identify the locality of the block that
> contains the few values, I might be able to push the B into the few
> nodes that contains the few values in A?  Since I only need to do this
> occasionally, maintaining a distributed database such as HBase cant be
> justified.
> Many thanks.
> Cao

Harsh J

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