It is necessary. We want to support input where IDs are possibly 64-bit longs, for consistency with the non-distributed code. But, 64-bit values are too large to be used as indexes into a Vector. So they are hashed and then un-hashed by a dictionary lookup.
On Tue, Sep 20, 2011 at 11:44 AM, 张玉东 <zhangyud...@vancl.cn> wrote: > Yes, the probability of collision is quite small. But I mean it is not > necessary to do this step, I can not find any help of it to the following > computations. >
