[ 
https://issues.apache.org/jira/browse/HIVE-20983?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16703080#comment-16703080
 ] 

Hive QA commented on HIVE-20983:
--------------------------------



Here are the results of testing the latest attachment:
https://issues.apache.org/jira/secure/attachment/12949955/HIVE-20983.1.patch

{color:red}ERROR:{color} -1 due to no test(s) being added or modified.

{color:red}ERROR:{color} -1 due to 7 failed/errored test(s), 15643 tests 
executed
*Failed tests:*
{noformat}
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastBytesHashMap.testExpand
 (batchId=315)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastBytesHashMultiSet.testExpand
 (batchId=315)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastBytesHashSet.testExpand
 (batchId=314)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastLongHashMap.testExpand
 (batchId=314)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastLongHashMapNonMatched.testExpand
 (batchId=314)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastLongHashMultiSet.testExpand
 (batchId=315)
org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.TestVectorMapJoinFastLongHashSet.testExpand
 (batchId=315)
{noformat}

Test results: 
https://builds.apache.org/job/PreCommit-HIVE-Build/15112/testReport
Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/15112/console
Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-15112/

Messages:
{noformat}
Executing org.apache.hive.ptest.execution.TestCheckPhase
Executing org.apache.hive.ptest.execution.PrepPhase
Executing org.apache.hive.ptest.execution.YetusPhase
Executing org.apache.hive.ptest.execution.ExecutionPhase
Executing org.apache.hive.ptest.execution.ReportingPhase
Tests exited with: TestsFailedException: 7 tests failed
{noformat}

This message is automatically generated.

ATTACHMENT ID: 12949955 - PreCommit-HIVE-Build

> Vectorization: Scale up small hashtables, when collisions are detected
> ----------------------------------------------------------------------
>
>                 Key: HIVE-20983
>                 URL: https://issues.apache.org/jira/browse/HIVE-20983
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Gopal V
>            Assignee: Gopal V
>            Priority: Major
>         Attachments: HIVE-20983.1.patch
>
>
> Hive's hashtable estimates are getting better with HyperLogLog stats in 
> place, but an accurate estimate does not always result in a low number of 
> collisions.
> The hashtables which contain a very small number of items tend to lose their 
> O(1) lookup performance where there are collisions. Since collisions are easy 
> to detect within the fast hashtable implementation, a rehashing to a higher 
> size will help these small hashtables avoid collisions and go back to O(1) 
> perf.



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

Reply via email to