No, values do not come in any order for a given key. But it is achievable.
If you need them to be ordered, you need to perform a secondary sort operation, by using multiple key components.
See this 3-part series on how to do that, for example: http://www.cloudera.com/blog/2011/04/simple-moving-average-secondary-sort-and-mapreduce-part-3/
On 06-Dec-2011, at 6:25 AM, James Y. Li wrote:
Hi All,
I just begin to use Hadoop framework, and write my reduce() method. Wonder if the Iterable input values (associated with the input key) are already sorted. Thanks!
p.s. I am using the version 0.20.2-cdh3u1
-james
--
Hi All,
I just begin to use Hadoop framework, and write my reduce() method. Wonder if the Iterable input values (associated with the input key) are already sorted. Thanks!
p.s. I am using the version 0.20.2-cdh3u1
-james
--
