[MDEV-30934] InnoDB: Changing a Column Data Type from VARCHAR/TEXT to a super type causes a unexpected Table Rebuild - Jira

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Details

Type: Bug
Status: Open (View Workflow)
Priority: Major
Resolution: Unresolved
Affects Version/s: 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 10.10, 10.11
Fix Version/s: 10.4, 10.5, 10.6, 10.11
Component/s: Data types, Storage Engine - InnoDB
Labels:
None

Description

CREATE OR REPLACE TABLE t1(a INT PRIMARY KEY, data TEXT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin) ENGINE=InnoDB;

--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON

ALTER TABLE t1 MODIFY data LONGTEXT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin, ALGORITHM=INSTANT;

InnoDB does not distinguish between VARCHAR, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT internally.
As long as the maximum length does not become smaller, the conversion can be done on the metadata level, without table rebuild (and without even validating the contents of the table).

Attachments

Issue Links

is blocked by

MDEV-30969 Some ALGORITHM=INSTANT checks are missing from handler::can_convert_nocopy()

Open

relates to

MDEV-16356 Allow ALGORITHM=NOCOPY for ADD CONSTRAINT

Open

MDEV-30669 Changing the Data Type of a Column from Text to JSON causes a unexpected Table Rebuild

Open

Activity

People

Assignee:: Alexander Barkov

Reporter:: Alexander Barkov

Votes:: 0 Vote for this issue

Watchers:: 1 Start watching this issue

Dates

Created:: 2023-03-27 07:47

Updated:: 2023-11-28 10:30

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