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
Attachments
Attachments
Issue Links
- is related to
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HIVE-12625 Backport to branch-1 HIVE-11981 ORC Schema Evolution Issues (Vectorized, ACID, and Non-Vectorized)
- Resolved
- relates to
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HIVE-14406 ORC should be supported in mixed file format tables
- Open
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HIVE-11981 ORC Schema Evolution Issues (Vectorized, ACID, and Non-Vectorized)
- Closed
- links to