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Namit Jain commented on HIVE-549: --------------------------------- I agree there may be some non-deterministic tests, but we should make them deterministic instead of deleting them. I will go over the tests above and get back to you > 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-v5.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.