[
https://issues.apache.org/jira/browse/HIVE-11981?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15011483#comment-15011483
]
Lefty Leverenz commented on HIVE-11981:
---------------------------------------
Doc note: This adds *hive.exec.schema.evolution* to HiveConf.java, so it needs
to be documented in the wiki. Although it seems to be a general parameter,
this JIRA issue is ORC-specific so the parameter should be cross-referenced at
the beginning of the ORC File Format section.
* [Configuration Properties -- Query and DDL Execution |
https://cwiki.apache.org/confluence/display/Hive/Configuration+Properties#ConfigurationProperties-QueryandDDLExecution]
* [Configuration Properties -- ORC File Format |
https://cwiki.apache.org/confluence/display/Hive/Configuration+Properties#ConfigurationProperties-ORCFileFormat]
Also, as Owen wrote: "You should create a wiki page with the supported schema
evolution."
Here's the existing doc:
https://issues.apache.org/jira/secure/attachment/12764089/ORC%20Schema%20Evolution%20Issues.docx.
> ORC Schema Evolution Issues (Vectorized, ACID, and Non-Vectorized)
> ------------------------------------------------------------------
>
> Key: HIVE-11981
> URL: https://issues.apache.org/jira/browse/HIVE-11981
> Project: Hive
> Issue Type: Bug
> Components: Hive, Transactions
> Reporter: Matt McCline
> Assignee: Matt McCline
> Priority: Critical
> Labels: TODOC2.0
> Fix For: 2.0.0
>
> Attachments: HIVE-11981.01.patch, HIVE-11981.02.patch,
> HIVE-11981.03.patch, HIVE-11981.05.patch, HIVE-11981.06.patch,
> HIVE-11981.07.patch, HIVE-11981.08.patch, HIVE-11981.09.patch,
> HIVE-11981.091.patch, HIVE-11981.092.patch, HIVE-11981.093.patch,
> HIVE-11981.094.patch, HIVE-11981.095.patch, HIVE-11981.096.patch,
> HIVE-11981.097.patch, HIVE-11981.098.patch, HIVE-11981.099.patch,
> HIVE-11981.0991.patch, HIVE-11981.0992.patch, ORC Schema Evolution Issues.docx
>
>
> High priority issues with schema evolution for the ORC file format.
> Schema evolution here is limited to adding new columns and a few cases of
> column type-widening (e.g. int to bigint).
> Renaming columns, deleting column, moving columns and other schema evolution
> were not pursued due to lack of importance and lack of time. Also, it
> appears a much more sophisticated metadata would be needed to support them.
> The biggest issues for users have been adding new columns for ACID table
> (HIVE-11421 Support Schema evolution for ACID tables) and vectorization
> (HIVE-10598 Vectorization borks when column is added to table).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
