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https://issues.apache.org/jira/browse/PHOENIX-4694?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16444883#comment-16444883
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James Taylor edited comment on PHOENIX-4694 at 4/19/18 10:10 PM:
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The lock on the parent during creation of a view is need to prevent a race 
condition between creating a view and adding/dropping a column from a base 
table. This will no longer be required after PHOENIX-3534. For now, we can 
reduce contention by not locking the parent during drop as that's not required.

Please review, [~vincentpoon].


was (Author: jamestaylor):
The lock on the parent during creation of a view is need to prevent a race 
condition between creating a view and adding/dropping a column from a base 
table. This will no longer be required after PHOENIX-3534. For now, we can 
reduce contention by not locking the parent during drop as that's not required.

> Prevent locking of parent table when dropping view to reduce contention
> -----------------------------------------------------------------------
>
>                 Key: PHOENIX-4694
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-4694
>             Project: Phoenix
>          Issue Type: Bug
>            Reporter: James Taylor
>            Priority: Major
>             Fix For: 4.14.0, 5.0.0
>
>         Attachments: PHOENIX-4694.patch
>
>
> When there are many views with the same parent table, there's a lot of 
> contention when adding new views and dropping existing views. The lock is 
> only necessary when creating/dropping indexes, so should be removed in the 
> case of views.



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