Github user rezazadeh commented on the pull request:

    https://github.com/apache/spark/pull/1778#issuecomment-56894583
  
    @mengxr Thanks for the optimizations. I merged the latest master into my 
branch and pushed to here. Would you like me to merge your branch into mine?
    
    There is no guarantee on sparsity, only on lower shuffle size, so what you 
observed is exactly what is expected. We can however allow the user to promote 
sparsity by allowing them to set the threshold to values greater than 1. In 
this case however, we can't provably guarantee correctness, but it will be 
useful for users who have very dense matrices, because the guarantees are 
pessimistic and even after promoting sparsity the result will likely be useful 
to them. 
    
    With this in mind, I propose allowing the threshold to be above 1, and when 
it is, instead of giving an error, give a warning that results are not 
guaranteed correct, but the computational savings will be useful. Shall I do 
that?


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to