[jira] [Work logged] (HIVE-23764) Remove unnecessary getLastFlushLength when checking delete delta files

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-23764?focusedWorklogId=451310&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-451310 ]

ASF GitHub Bot logged work on HIVE-23764:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 25/Jun/20 22:08
            Start Date: 25/Jun/20 22:08
    Worklog Time Spent: 10m 
      Work Description: pvary opened a new pull request #1185:
URL: https://github.com/apache/hive/pull/1185


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Issue Time Tracking
-------------------

            Worklog Id:     (was: 451310)
    Remaining Estimate: 0h
            Time Spent: 10m

> Remove unnecessary getLastFlushLength when checking delete delta files
> ----------------------------------------------------------------------
>
>                 Key: HIVE-23764
>                 URL: https://issues.apache.org/jira/browse/HIVE-23764
>             Project: Hive
>          Issue Type: Improvement
>          Components: Transactions
>            Reporter: Peter Vary
>            Assignee: Peter Vary
>            Priority: Major
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> VectorizedOrcAcidRowBatchReader$ColumnizedDeleteEventRegistry calls OrcAcidUtils.getLastFlushLength for every delete delta file.
> Even the comment says:
> {code}
>               // NOTE: Calling last flush length below is more for future-proofing when we have
>               // streaming deletes. But currently we don't support streaming deletes, and this can
>               // be removed if this becomes a performance issue.
> {code}
> If we have a table with 5 updates (1 base + 5 delta + 5 delete_delta), then for every base + delta dir we will check all of the delete_delta directories, and check the getLastFlushLength method which will result in 6*5=30 unnecessary NN/S3 calls.
> We should remove the check as already proposed in the comment.



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