[
https://issues.apache.org/jira/browse/HIVE-12839?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15125467#comment-15125467
]
Ashutosh Chauhan commented on HIVE-12839:
-----------------------------------------
With upgrade to 1.6 limit join transpose rule is kicking in. But for Hive it
may generate a worse plan. See, changes in limit_join_transpose.q where because
limit was pushed through join, we end up generating an extra MR job, since to
force limit we blindly force all rows to go through one reducer, thus requiring
extra job, which here is unnecessary. We need to make changes in Hive physical
compiler not to force extra MR stage for such case. See related : HIVE-12963
cc: [~jcamachorodriguez]
> Upgrade Hive to Calcite 1.6
> ---------------------------
>
> Key: HIVE-12839
> URL: https://issues.apache.org/jira/browse/HIVE-12839
> Project: Hive
> Issue Type: Improvement
> Reporter: Pengcheng Xiong
> Assignee: Pengcheng Xiong
> Attachments: HIVE-12839.01.patch, HIVE-12839.02.patch,
> HIVE-12839.03.patch
>
>
> CLEAR LIBRARY CACHE
> Upgrade Hive to Calcite 1.6.0-incubating.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
