[
https://issues.apache.org/jira/browse/HIVE-352?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12700941#action_12700941
]
Zheng Shao commented on HIVE-352:
---------------------------------
I agree we should do 1 and 2, but I don't feel 3 is worth to do.
As you mentioned, 3 will have memory problems when the number of columns grows
very big - in that case, performance degradation is better than out-of-memory
problem.
For 3 the eventual solution would be to fix DFSClient to use a smaller number
than TCP_WINDOW_SIZE. But if it is not easy to change DFSClient, and we
continue to see this problem, we may want to switch to other solutions (B1
etc). Anyway, if TCP_WINDOW_SIZE is 128KB, and we have 20MB buffer (compressed
size), we should be able to handle 160 columns, which is usually good enough
for most applications.
> Make Hive support column based storage
> --------------------------------------
>
> Key: HIVE-352
> URL: https://issues.apache.org/jira/browse/HIVE-352
> Project: Hadoop Hive
> Issue Type: New Feature
> Reporter: He Yongqiang
> Assignee: He Yongqiang
> Attachments: hive-352-2009-4-15.patch, hive-352-2009-4-16.patch,
> hive-352-2009-4-17.patch, hive-352-2009-4-19.patch,
> HIve-352-draft-2009-03-28.patch, Hive-352-draft-2009-03-30.patch
>
>
> column based storage has been proven a better storage layout for OLAP.
> Hive does a great job on raw row oriented storage. In this issue, we will
> enhance hive to support column based storage.
> Acctually we have done some work on column based storage on top of hdfs, i
> think it will need some review and refactoring to port it to Hive.
> Any thoughts?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
