[jira] [Created] (ARROW-1571) [C++] Implement argsort kernels (sort indices) for integers using O(n) counting sort

["Wes McKinney (JIRA)" <ji...@apache.org>]

Wes McKinney created ARROW-1571:
-----------------------------------

             Summary: [C++] Implement argsort kernels (sort indices) for integers using O(n) counting sort
                 Key: ARROW-1571
                 URL: https://issues.apache.org/jira/browse/ARROW-1571
             Project: Apache Arrow
          Issue Type: New Feature
          Components: C++
            Reporter: Wes McKinney


This function requires knowledge of the minimum and maximum of an array. If it is small enough, then an array of size {{maximum - minimum}} can be constructed and used to tabulate value frequencies and then compute the sort indices (this is called "grade up" or "grade down" in APL languages). There is generally a cross-over point where this function performs worse than mergesort or quicksort due to data locality issues



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)