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https://issues.apache.org/jira/browse/HIVE-15774?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15850590#comment-15850590
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Wei Zheng commented on HIVE-15774:
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Committed to master
> Ensure DbLockManager backward compatibility for non-ACID resources
> ------------------------------------------------------------------
>
> Key: HIVE-15774
> URL: https://issues.apache.org/jira/browse/HIVE-15774
> Project: Hive
> Issue Type: Improvement
> Components: Hive, Transactions
> Reporter: Wei Zheng
> Assignee: Wei Zheng
> Attachments: HIVE-15774.1.patch, HIVE-15774.2.patch,
> HIVE-15774.3.patch
>
>
> In pre-ACID days, users perform operations such as INSERT with either
> ZooKeeperHiveLockManager or no lock manager at all. If their workflow is
> designed to take advantage of no locking and they take care of the control of
> concurrency, this works well with good performance.
> With ACID, if users enable transactions (i.e. using DbTxnManager &
> DbLockManager), then for all the operations, different types of locks will be
> acquired accordingly by DbLockManager, even for non-ACID resources. This may
> impact the performance of some workflows designed for pre-ACID use cases.
> A viable solution would be to differentiate the locking mode for ACID and
> non-ACID resources, so that DbLockManager will continue its current behavior
> for ACID tables, but will be able to acquire a less strict lock type for
> non-ACID resources, thus avoiding the performance loss for those workflows.
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