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  1. Hive
  2. HIVE-23764

Remove unnecessary getLastFlushLength when checking delete delta files

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      VectorizedOrcAcidRowBatchReader$ColumnizedDeleteEventRegistry calls OrcAcidUtils.getLastFlushLength for every delete delta file.
      Even the comment says:

                    // 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.
      

      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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              • Assignee:
                rajesh.balamohan Rajesh Balamohan
                Reporter:
                pvary Peter Vary
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