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https://issues.apache.org/jira/browse/HIVE-12728?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Prasanth Jayachandran updated HIVE-12728:
-----------------------------------------
Description:
HIVE-11981 added schema evolution for ORC. However, it does not enforce any
restrictions in DDL that can break schema evolution. Following changes have to
be enforced in DDL to support the assumptions in schema evolution (that columns
will only be added).
1) Restrict changing the file format of the table
2) Restrict changing the serde of the table
3) Restrict replacing columns to not drop columns or do unsupported type
widening
4) Restrict reordering columns
5) Restrict unsupported type promotions
was:
HIVE-11981 added schema evolution for ORC. However, it does not enforce any
restrictions in DDL that can break schema evolution. Following changes have to
be enforced in DDL to support the assumptions in schema evolution (that columns
will only be added).
1) Restrict changing the file format of the table
2) Restrict changing the serde of the table
3) Restrict replacing columns
4) Restrict reordering columns
5) Restrict unsupported type promotions
> Apply DDL restrictions for ORC schema evolution
> -----------------------------------------------
>
> Key: HIVE-12728
> URL: https://issues.apache.org/jira/browse/HIVE-12728
> Project: Hive
> Issue Type: Bug
> Affects Versions: 2.0.0, 2.1.0
> Reporter: Prasanth Jayachandran
> Assignee: Prasanth Jayachandran
> Priority: Critical
> Attachments: HIVE-12728.1.patch, HIVE-12728.2.patch
>
>
> HIVE-11981 added schema evolution for ORC. However, it does not enforce any
> restrictions in DDL that can break schema evolution. Following changes have
> to be enforced in DDL to support the assumptions in schema evolution (that
> columns will only be added).
> 1) Restrict changing the file format of the table
> 2) Restrict changing the serde of the table
> 3) Restrict replacing columns to not drop columns or do unsupported type
> widening
> 4) Restrict reordering columns
> 5) Restrict unsupported type promotions
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