data inconsistent when time data type is pk

[wk989898]

What did you do?

1. start a changefeed with mysql
2. run sql

CREATE TABLE time_is_pk
(
    id time(3) NOT NULL,
    t  datetime DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (id)
);

INSERT INTO `time_is_pk`(id) VALUES ('517:51:04.777'),('-733:00:00.0011');
DELETE FROM `time_is_pk` WHERE id = '517:51:04.777';

What did you expect to see?

No response

What did you see instead?

The following tables contains inconsistent data

+-------------------------+---------+--------------------+----------------+---------+-----------+
|          TABLE          | RESULT  | STRUCTURE EQUALITY | DATA DIFF ROWS | UPCOUNT | DOWNCOUNT |
+-------------------------+---------+--------------------+----------------+---------+-----------+
| `common_1`.`time_is_pk` | succeed | true               | +1/-1          |       1 |         1 |
+-------------------------+---------+--------------------+----------------+---------+-----------+

fix sql

-- table: common_1.time_is_pk
-- range in sequence: Full
DELETE FROM `common_1`.`time_is_pk` WHERE `id` = '-733:00:00.000' AND `t` = '2026-02-26 08:50:08' LIMIT 1;
REPLACE INTO `common_1`.`time_is_pk`(`id`,`t`) VALUES ('-733:00:00.001','2026-02-26 08:50:08');

Versions of the cluster

Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

(paste TiCDC version here)

[wk989898]

The root reason is that Duration type values were not being processed with their intended precision.
Affected area:

• the dispatcher partition calculation in Kafka
• the open protocol output
• MySQL data inconsistency