[jira] [Created] (HIVE-4103) Remove System.gc() call from the map-join local-task loop

["Gopal V (JIRA)" <ji...@apache.org>]

Gopal V created HIVE-4103:
-----------------------------

             Summary: Remove System.gc() call from the map-join local-task loop
                 Key: HIVE-4103
                 URL: https://issues.apache.org/jira/browse/HIVE-4103
             Project: Hive
          Issue Type: Bug
            Reporter: Gopal V


Hive's HashMapWrapper calls System.gc() twice within the HashMapWrapper::isAbort() which produces a significant slow-down during the loop.

{code}
2013-03-01 04:54:28 The gc calls took 677 ms
2013-03-01 04:54:28     Processing rows:        200000  Hashtable size: 199999  Memory usage:   62955432        rate:   0.033
2013-03-01 04:54:31 The gc calls took 956 ms
2013-03-01 04:54:31     Processing rows:        300000  Hashtable size: 299999  Memory usage:   90826656        rate:   0.048
2013-03-01 04:54:33 The gc calls took 967 ms
2013-03-01 04:54:33     Processing rows:        384160  Hashtable size: 384160  Memory usage:   114412712       rate:   0.06
{code}

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira