Substream applied to unordered streams
aph at redhat.com
Tue Mar 19 02:54:49 PDT 2013
On 03/16/2013 08:52 PM, Brian Goetz wrote:
> I haven't yet determined whether we want to commit to stable sorting.
> But I think we probably do not. Stability is a relatively cheap
> property to preserve in a sequential sort (which is why Arrays.sort is
> spec'ed as stable), but a relatively expensive property to preserve in
> an parallel sort, and this moves the balance of whether stability is
> worth the cost.
Why? Merge sorting is usually stable, and parallel sorting is Xsort
followed by a bunch of merges. What is it about parallel sorting that
makes stability expensive?
I guess there's something I must be missing. Stability is an
extremely useful property.
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