[
https://issues.apache.org/jira/browse/HIVE-6734?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13949658#comment-13949658
]
Alan Gates commented on HIVE-6734:
----------------------------------
I changed the grain of locking for DDL statements. In the initial checkin I
had set all DDL statements to exclusive lock. But this results in a whole
table being locked so that a partition can be added. This is excessive. So I
went back and added a DDL_EXCLUSIVE, DDL_SHARED, and DDL_NO_LOCK so that
different DDL statements could obtain appropriate grains of locks. For
example, add partition is now a shared lock, drop partition is an exclusive
lock, and add function is no lock.
> DDL locking too course grained in new db txn manager
> ----------------------------------------------------
>
> Key: HIVE-6734
> URL: https://issues.apache.org/jira/browse/HIVE-6734
> Project: Hive
> Issue Type: Bug
> Components: Locking
> Affects Versions: 0.13.0
> Reporter: Alan Gates
> Assignee: Alan Gates
> Fix For: 0.13.0
>
> Attachments: HIVE-6734.patch
>
>
> All DDL operations currently acquire an exclusive lock. This is too course
> grained, as some operations like alter table add partition shouldn't get an
> exclusive lock on the entire table.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
