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Posted to dev@hive.apache.org by "Gopal V (JIRA)" <ji...@apache.org> on 2014/10/04 07:19:34 UTC
[jira] [Commented] (HIVE-8292) Reading from partitioned bucketed
tables has high overhead in MapOperator.cleanUpInputFileChangedOp
[ https://issues.apache.org/jira/browse/HIVE-8292?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14158966#comment-14158966 ]
Gopal V commented on HIVE-8292:
-------------------------------
Traced it down to
{code}
@Override
public boolean pushRecord() throws HiveException {
execContext.resetRow(); <-- resets input checks
{code}
This is why the cleanup input is being called once per row.
> Reading from partitioned bucketed tables has high overhead in MapOperator.cleanUpInputFileChangedOp
> ---------------------------------------------------------------------------------------------------
>
> Key: HIVE-8292
> URL: https://issues.apache.org/jira/browse/HIVE-8292
> Project: Hive
> Issue Type: Bug
> Components: Query Processor
> Affects Versions: 0.14.0
> Environment: cn105
> Reporter: Mostafa Mokhtar
> Assignee: Prasanth J
> Fix For: 0.14.0
>
> Attachments: 2014_09_29_14_46_04.jfr
>
>
> Reading from bucketed partitioned tables has significantly higher overhead compared to non-bucketed non-partitioned files.
> 50% of the profile is spent in MapOperator.cleanUpInputFileChangedOp
> 5% the CPU in
> {code}
> Path onepath = normalizePath(onefile);
> {code}
> And
> 45% the CPU in
> {code}
> onepath.toUri().relativize(fpath.toUri()).equals(fpath.toUri());
> {code}
> From the profiler
> {code}
> Stack Trace Sample Count Percentage(%)
> hive.ql.exec.tez.MapRecordSource.processRow(Object) 5,327 62.348
> hive.ql.exec.vector.VectorMapOperator.process(Writable) 5,326 62.336
> hive.ql.exec.Operator.cleanUpInputFileChanged() 4,851 56.777
> hive.ql.exec.MapOperator.cleanUpInputFileChangedOp() 4,849 56.753
> java.net.URI.relativize(URI) 3,903 45.681
> java.net.URI.relativize(URI, URI) 3,903 45.681
> java.net.URI.normalize(String) 2,169 25.386
> java.net.URI.equal(String, String) 526 6.156
> java.net.URI.equalIgnoringCase(String, String) 1 0.012
> java.lang.String.substring(int) 1 0.012
> hive.ql.exec.MapOperator.normalizePath(String) 506 5.922
> org.apache.commons.logging.impl.Log4JLogger.info(Object) 32 0.375
> java.net.URI.equals(Object) 12 0.14
> java.util.HashMap$KeySet.iterator() 5 0.059
> java.util.HashMap.get(Object) 4 0.047
> java.util.LinkedHashMap.get(Object) 3 0.035
> hive.ql.exec.Operator.cleanUpInputFileChanged() 1 0.012
> hive.ql.exec.Operator.forward(Object, ObjectInspector) 473 5.536
> hive.ql.exec.mr.ExecMapperContext.inputFileChanged() 1 0.012
> {code}
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