add REORGANIZE PARTITION as medata lock example

[yahonda]

What is changed, added or deleted? (Required)

This pull request adds the REORGANIZE PARTITION operation requires metadata lock.

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[gemini-code-assist]

Summary of Changes

Hello @yahonda, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the accuracy of the TiDB documentation by explicitly listing the REORGANIZE PARTITION operation among the DDL statements that necessitate a metadata lock. This ensures that users are fully informed about the concurrency implications when performing partition reorganization.

Highlights

• Documentation Update: The documentation for metadata locks has been updated to include REORGANIZE PARTITION as a DDL statement that requires a metadata lock.

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[gemini-code-assist]

Code Review

This pull request correctly adds REORGANIZE PARTITION to the list of DDL statements that require a metadata lock. To enhance readability, I've suggested alphabetically sorting the list of statements. Additionally, please correct the typo in the pull request title from "medata" to "metadata".

[yahonda]

Here are test scenario to make sure reorganize partition requires metadata lock.

1. Startup TiDB Playground

% tiup playground # v8.5.3

2. create events table

% mysql --host 127.0.0.1 --port 4000 -u root test
CREATE TABLE events (
  id INT,
  name VARCHAR(255),
  event_date DATE
)
PARTITION BY RANGE (YEAR(event_date)) (
  PARTITION pBefore1950 VALUES LESS THAN (1950),
  PARTITION p1950      VALUES LESS THAN (1960),
  PARTITION p1960      VALUES LESS THAN (1970),
  PARTITION p1970      VALUES LESS THAN (1980),
  PARTITION p1980      VALUES LESS THAN (1990),
  PARTITION p1990      VALUES LESS THAN (2000),
  PARTITION pMax       VALUES LESS THAN MAXVALUE
);

3. Open terminal 1

% mysql --host 127.0.0.1 --port 4000 -u root test
prompt t1> 
begin;
INSERT INTO events (id, name, event_date) VALUES (1, 'foo', '1949-12-31');
INSERT INTO events (id, name, event_date) VALUES (2, 'bar', '1959-12-31');
-- Do not commit yet;

4. Open terminal 2

mysql --host 127.0.0.1 --port 4000 -u root test
prompt t2> 
ALTER TABLE events REORGANIZE PARTITION pBefore1950,p1950 INTO 
(PARTITION pBefore1960 VALUES LESS THAN (1960));
/* this REORGANIZE PARTITION operation wait for the transacion terminal 1*/

5. Commit the transaction at t1 then the ALTER TABLE events REORGANIZE PARTITION operation t2 will be finished.

[yahonda]

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-11-03 06:24:49.999869344 +0000 UTC m=+78539.442899222: ☑️ agreed by qiancai.

[mjonss]

LGTM

[ti-chi-bot]

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LGTM

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[qiancai]

/approve

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.5: #22163.