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https://issues.apache.org/jira/browse/HIVE-14035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15408584#comment-15408584
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Sergey Shelukhin commented on HIVE-14035:
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Actually, one good thing to do would be to enable it by default in the next
patch and see what HiveQA run, with all the existing ACID tests running in new
mode, shows.
> Enable predicate pushdown to delta files created by ACID Transactions
> ---------------------------------------------------------------------
>
> Key: HIVE-14035
> URL: https://issues.apache.org/jira/browse/HIVE-14035
> Project: Hive
> Issue Type: New Feature
> Components: Transactions
> Reporter: Saket Saurabh
> Assignee: Saket Saurabh
> Attachments: HIVE-14035.02.patch, HIVE-14035.03.patch,
> HIVE-14035.04.patch, HIVE-14035.05.patch, HIVE-14035.06.patch,
> HIVE-14035.07.patch, HIVE-14035.08.patch, HIVE-14035.09.patch,
> HIVE-14035.10.patch, HIVE-14035.11.patch, HIVE-14035.12.patch,
> HIVE-14035.patch
>
>
> In current Hive version, delta files created by ACID transactions do not
> allow predicate pushdown if they contain any update/delete events. This is
> done to preserve correctness when following a multi-version approach during
> event collapsing, where an update event overwrites an existing insert event.
> This JIRA proposes to split an update event into a combination of a delete
> event followed by a new insert event, that can enable predicate push down to
> all delta files without breaking correctness. To support backward
> compatibility for this feature, this JIRA also proposes to add some sort of
> versioning to ACID that can allow different versions of ACID transactions to
> co-exist together.
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