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https://issues.apache.org/jira/browse/HIVE-14035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15431610#comment-15431610
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Eugene Koifman commented on HIVE-14035:
---------------------------------------
Sorry, I realized my comment was not clear. I was referring to the
hive.txn.operational.properties, not the whole feature.
> 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
> Fix For: 2.2.0
>
> Attachments: Design.Document.Improving ACID performance in
> Hive.01.docx, Design.Document.Improving ACID performance in Hive.02.docx,
> 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-14035.13.patch,
> HIVE-14035.14.patch, HIVE-14035.15.patch, HIVE-14035.16.patch,
> HIVE-14035.17.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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