Hi Gang,

What's your reduce output key type? It looks like you're using Text
instead of IntWritable, causing your keys to be sorted
lexicographically instead of numerically.

Sorting is done with a comparator that defines how an arbitrary
element compares to another. Hashing serves a different purpose.

Ed

On Sun, Feb 28, 2010 at 4:23 PM, Gang Luo <[email protected]> wrote:
> Hi all,
> here is a wired observation. The keys in the result of *ONE* reducer are 
> ordered like this:
> 18166
> 18169
> 1817
> 18171
> 18172
>
> why is key "1817" comes after "18169"? It makes sense if that key is "18170" 
> but it isn't! Why does it happen and basically, how does hadoop tell key1 is 
> larger than key2? Compare their hash codes?
>
> Thanks.
> -Gang
>
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