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https://issues.apache.org/jira/browse/IMPALA-14589?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18087074#comment-18087074
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ASF subversion and git services commented on IMPALA-14589:
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Commit 0d1dbd94661fcd7cc974bc046002a6e0da3db575 in impala's branch
refs/heads/master from Arnab Karmakar
[ https://gitbox.apache.org/repos/asf?p=impala.git;h=0d1dbd946 ]
IMPALA-14589: [Part 4] Add Iceberg V3 DDL support for column defaults
This patch wires Iceberg V3 initial-default and write-default literals
into DDL so Impala can define defaults at table creation and via
schema evolution.
DDL semantics:
- CREATE TABLE ... DEFAULT: sets both initial-default and write-default
on new columns.
- ALTER TABLE ADD COLUMN ... DEFAULT: sets both initial-default and
write-default (backfills existing rows on read, applies on future writes).
- ALTER TABLE ALTER COLUMN ... SET DEFAULT: sets write-default only;
rows written before the change are not actively filled.
- ALTER TABLE ALTER COLUMN ... DROP DEFAULT: drops write-default only;
rows written before the change continue to project the previous default.
Type support:
Supported: BOOLEAN, INT, BIGINT, FLOAT, DOUBLE, DECIMAL, STRING, DATE
Unsupported: BINARY, TIMESTAMP, complex types
Testing:
- Positive tests:
- CREATE TABLE with all supported scalar DEFAULTs
- ADD COLUMN ... DEFAULT on existing data
- ALTER COLUMN SET DEFAULT on all scalar types
- ALTER COLUMN DROP DEFAULT: clears write-default;
initial-default remains unchanged.
- Negative tests:
- format-version < 3 rejects CREATE/ADD/ALTER COLUMN default DDL
- BINARY and TIMESTAMP default rejection on CREATE and ADD COLUMN
- Non-constant complex defaults (array/map) rejected at analysis
Change-Id: Ibec771f324a0a9534e767e4b1fc66b25b41483ae
Reviewed-on: http://gerrit.cloudera.org:8080/24386
Reviewed-by: Impala Public Jenkins <[email protected]>
Tested-by: Impala Public Jenkins <[email protected]>
> Iceberg V3 default values
> -------------------------
>
> Key: IMPALA-14589
> URL: https://issues.apache.org/jira/browse/IMPALA-14589
> Project: IMPALA
> Issue Type: New Feature
> Components: Backend, Frontend
> Reporter: Zoltán Borók-Nagy
> Assignee: Arnab Karmakar
> Priority: Major
> Labels: impala-iceberg
>
> Implement default value support for columns.
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