They are valid, especially in partition pruning.
On Friday, September 16, 2016, Sean Owen <so...@cloudera.com> wrote:
> There are almost no cases in which you'd want a zero-partition RDD.
> The only one I can think of is an empty RDD, where the number of
> partitions is irrelevant. Still, I would not be surprised if other
> parts of the code assume at least 1 partition.
>
> Maybe this check could be tightened. It would be interesting to see if
> the tests catch any scenario where a 0-partition RDD is created, and
> why.
>
> On Fri, Sep 16, 2016 at 7:54 AM, WangJianfei
> <wangjianfe...@otcaix.iscas.ac.cn <javascript:;>> wrote:
> > class HashPartitioner(partitions: Int) extends Partitioner {
> > require(partitions >= 0, s"Number of partitions ($partitions) cannot be
> > negative.")
> >
> > the soruce code require(partitions >=0) ,but I don't know why it makes
> sense
> > when the partitions is 0.
> >
> >
> >
> > --
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> when-the-partitions-is-zero-tp18957.html
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