Rui Shi wrote:
Hi,
I need to sort the data by multiple keys. Is there any built-in support in Hadoop?
Rui, could you sketch the exact task on hand for us?
Generally, the idea to set the map-output keys to be _complex_ and
define necessary comparators to sort by multiple keys.
E.g.
Map-input: <K1, V1>
Map-output: <(K2, K3), V2>
Reduce-output: <K4, V3>
So, as long as you have the necessary comparator defined for (K2, K3)
you are golden.
Does that work for you?
Arun
Thanks,
Rui
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