[jira] [Updated] (HIVE-24670) DeleteReaderValue should not allocate empty vectors for delete delta files

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

     [ https://issues.apache.org/jira/browse/HIVE-24670?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

ASF GitHub Bot updated HIVE-24670:
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    Labels: pull-request-available  (was: )

> DeleteReaderValue should not allocate empty vectors for delete delta files
> --------------------------------------------------------------------------
>
>                 Key: HIVE-24670
>                 URL: https://issues.apache.org/jira/browse/HIVE-24670
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Ádám Szita
>            Assignee: Ádám Szita
>            Priority: Major
>              Labels: pull-request-available
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> If delete delta caching is turned off, the plain record reader inside DeleteReaderValue allocates a batch with a schema that is equivalent to that of an insert delta.
> This is unnecessary as the struct part in a delete delta file is always empty. In cases where we have many delete delta files (e.g. due to compaction failures) and a wide table definition (e.g. 200+ cols) this puts a significant amount of memory pressure on the executor, while these empty structures will never be filled or otherwise utilized.
> I propose we specify an ACID schema with an empty struct part to this record reader to counter this.



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