[
https://issues.apache.org/jira/browse/HIVE-549?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12776006#action_12776006
]
Zheng Shao commented on HIVE-549:
---------------------------------
Hi Chaitanya, the code looks good to me except a small nitch: can you change
the logic of "shouldLaunch()"? Currently it means "shouldNotLaunch()".
After you have done that, please test again with "ant test -logfile log.txt"
and make sure all tests are passing.
Then we can commit it.
> Parallel Execution Mechanism
> ----------------------------
>
> Key: HIVE-549
> URL: https://issues.apache.org/jira/browse/HIVE-549
> Project: Hadoop Hive
> Issue Type: Wish
> Components: Query Processor
> Reporter: Adam Kramer
> Assignee: Chaitanya Mishra
> Attachments: HIVE-549-v4.patch
>
>
> In a massively parallel database system, it would be awesome to also
> parallelize some of the mapreduce phases that our data needs to go through.
> One example that just occurred to me is UNION ALL: when you union two SELECT
> statements, effectively you could run those statements in parallel. There's
> no situation (that I can think of, but I don't have a formal proof) in which
> the left statement would rely on the right statement, or vice versa. So, they
> could be run at the same time...and perhaps they should be. Or, perhaps there
> should be a way to make this happen...PARALLEL UNION ALL? PUNION ALL?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
