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https://issues.apache.org/jira/browse/HIVE-15774?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15851000#comment-15851000
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Lefty Leverenz commented on HIVE-15774:
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Thanks for the docs, [~wzheng].  Here's the link for 
*hive.txn.strict.locking.mode*:

* [hive.txn.strict.locking.mode | 
https://cwiki.apache.org/confluence/display/Hive/Configuration+Properties#ConfigurationProperties-hive.txn.strict.locking.mode]

> 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
>             Fix For: 2.2.0
>
>         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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