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Merge pull request #64056 from jrdi/fix-rmt-is-deleted-docs

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Improve ReplacingMergeTree is_deleted documentation
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Alexey Milovidov 2024-05-18 07:28:22 +02:00 committed by GitHub
commit 5f938c9c2d
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1 changed files with 8 additions and 7 deletions
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docs/en/engines/table-engines/mergetree-family/replacingmergetree.md
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@ -90,14 +90,14 @@ SELECT * FROM mySecondReplacingMT FINAL;
### is_deleted
`is_deleted` — Name of a column used during a merge to determine whether the data in this row represents the state or is to be deleted; `1` is a “deleted“ row, `0` is a “state“ row.
`is_deleted` — Name of a column used during a merge to determine whether the data in this row represents the state or is to be deleted; `1` is a "deleted" row, `0` is a "state" row.
Column data type — `UInt8`.
:::note
`is_deleted` can only be enabled when `ver` is used.
The row is deleted when `OPTIMIZE ... FINAL CLEANUP` or `OPTIMIZE ... FINAL` is used.
The row is deleted only when `OPTIMIZE ... FINAL CLEANUP`. This `CLEANUP` special keyword is not allowed by default unless `allow_experimental_replacing_merge_with_cleanup` MergeTree setting is enabled.
No matter the operation on the data, the version must be increased. If two inserted rows have the same version number, the last inserted row is the one kept.
@ -114,7 +114,8 @@ CREATE OR REPLACE TABLE myThirdReplacingMT
`is_deleted` UInt8
)
ENGINE = ReplacingMergeTree(eventTime, is_deleted)
ORDER BY key;
ORDER BY key
SETTINGS allow_experimental_replacing_merge_with_cleanup = 1;
INSERT INTO myThirdReplacingMT Values (1, 'first', '2020-01-01 01:01:01', 0);
INSERT INTO myThirdReplacingMT Values (1, 'first', '2020-01-01 01:01:01', 1);