You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@hive.apache.org by "Namit Jain (JIRA)" <ji...@apache.org> on 2009/03/09 23:19:50 UTC
[jira] Updated: (HIVE-318) [Hive] union all queries broken - all
kinds of problems
[ https://issues.apache.org/jira/browse/HIVE-318?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Namit Jain updated HIVE-318:
----------------------------
Attachment: hive.318.patch
> [Hive] union all queries broken - all kinds of problems
> -------------------------------------------------------
>
> Key: HIVE-318
> URL: https://issues.apache.org/jira/browse/HIVE-318
> Project: Hadoop Hive
> Issue Type: Bug
> Components: Query Processor
> Reporter: Namit Jain
> Assignee: Namit Jain
> Attachments: hive.318.patch
>
>
> 1. Map-only job : same input
> Hangs because mapper tries to same open twice, and hadoop filesystem complains.
> Fix: Only initialize once - keep state at the Operator level for the same. Should do same for Close.
> 2. Map-only job : different inputs
> Loss of data due to rename.
> Fix: change rename to move files to the directory.
> 3. Map-only job in subquery + RedSink: works currently
> 4. 2 variables: so 4 sub-cases
> Number of sub-queries having map-reduce jobs. (1/2)
> Operator after Union (RS/FS)
>
> a. Number of sub-queries having map-reduce jobs. 1
> Operator after Union: RS
> Can be done in 2MR - really difficult with current infrastructure.
> Should do with 3 MR jobs now - break on top of UNION.
> Future optimization: move operators between Union and RS before Union.
> b. Number of sub-queries having map-reduce jobs. 2
> Operator after Union: RS
> Needs 3MR - Should do with 3 MR jobs - break on top of UNION.
> Future optimization: move operators between Union and RS before Union.
> c. Number of sub-queries having map-reduce jobs. 1
> Operator after Union: FS
> Can be done in 1MR - really difficult with current infrastructure.
> Can be easily done with 2 MR by removing UNION and cloning operators between Union and FS.
> Should do with 3 MR jobs now - break on top of UNION.
> Followup optimization: 2MR should be able to handle
> d. Number of sub-queries having map-reduce jobs. 2
> Operator after Union: FS
> Can be easily done with 2 MR by removing UNION and cloning operators between Union and FS.
> Should do with 3 MR jobs now - break on top of UNION.
> Followup optimization: 2MR should be able to handle
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.