You are viewing a plain text version of this content. The canonical link for it is here.

Posted to dev@hive.apache.org by "Matt McCline (JIRA)" <ji...@apache.org> on 2018/02/01 08:37:00 UTC

[jira] [Created] (HIVE-18600) Vectorization: Top-Level Vector Expression Scratch Column Deallocation

Matt McCline created HIVE-18600:
-----------------------------------

             Summary: Vectorization: Top-Level Vector Expression Scratch Column Deallocation
                 Key: HIVE-18600
                 URL: https://issues.apache.org/jira/browse/HIVE-18600
             Project: Hive
          Issue Type: Bug
          Components: Hive
            Reporter: Matt McCline
            Assignee: Matt McCline
             Fix For: 3.0.0


The operators create various vector expression *arrays* for predicates, SELECT clauses, key expressions, etc.  We could have those be marked as special "top level" vector expression then we could defer deallocation until the top level expression is complete.  This could be a simple solution that avoids trying fix our current eager deallocation that tries to reuse scratch columns as soon as possible.  It *isn't optimal*, but it *shouldn't be too bad*. This solution is much better than not deallocating at all - especially for queries that SELECT a large number of columns or have a lot of expressions in the operator tree.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)