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Hive, mail # user - Query regarding Hive Parallel Orderby


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Query regarding Hive Parallel Orderby
Vaibhav Jain 2014-02-21, 04:32
Hi,

Hive 12 has added the functionality of parallel order by. I have a few
queries regarding the working of it.
From the source code I have figured out that to do a parallel orderby , a
partition table needs to created
which is provided as an input to TotalOrderPartitioner.  To create the
partition table, a sample of
the hive table is stored as ArrayList of byte arrays and then sorted.

So I have the following queries :

1)  Is my understanding correct?

2) Isn't it a possibility that storing the entire sample in memory would
become a bottleneck when the sample size is large?
Thanks
Vaibhav Jain