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https://issues.apache.org/jira/browse/HIVE-11981?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15013146#comment-15013146
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Carl Steinbach commented on HIVE-11981:
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bq. This adds hive.exec.schema.evolution to HiveConf.java ... Although it seems
to be a general parameter, this JIRA issue is ORC-specific...
If this property is ORC specific then it seems like a mistake to name it
hive.exec.orc.schema.evolution. Is there a good reason why "orc" doesn't appear
in the property name or property description?
> 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).
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