[
https://issues.apache.org/jira/browse/HIVE-6430?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Sergey Shelukhin updated HIVE-6430:
-----------------------------------
Attachment: HIVE-6430.02.patch
Addressed major review and discussion feedback. I kept the list bit in the ref
though, because putting it in the array results in huge pita w/retrieval of the
union. Removed the "split" long, now everything is in one place.
Probably need to write some unit tests, q files do not cover all cases. Will do
so later today or maybe sunday
> MapJoin hash table has large memory overhead
> --------------------------------------------
>
> Key: HIVE-6430
> URL: https://issues.apache.org/jira/browse/HIVE-6430
> Project: Hive
> Issue Type: Improvement
> Reporter: Sergey Shelukhin
> Assignee: Sergey Shelukhin
> Attachments: HIVE-6430.01.patch, HIVE-6430.02.patch, HIVE-6430.patch
>
>
> Right now, in some queries, I see that storing e.g. 4 ints (2 for key and 2
> for row) can take several hundred bytes, which is ridiculous. I am reducing
> the size of MJKey and MJRowContainer in other jiras, but in general we don't
> need to have java hash table there. We can either use primitive-friendly
> hashtable like the one from HPPC (Apache-licenced), or some variation, to map
> primitive keys to single row storage structure without an object per row
> (similar to vectorization).
--
This message was sent by Atlassian JIRA
(v6.2#6252)
