should split DDL for ADD COLUMN (c1 int, c2 int)

[lance6716]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do? If possible, provide a recipe for reproducing the error.

in upstream.

ALTER TABLE `all_mode`.`t1` ADD COLUMN (`t6` INT, `t7` INT)

2. What did you expect to see?

sync to downstream, split same as

alter table t1 add column t6 int, add column t7 int;

3. What did you see instead?

                                "Message": "startLocation: [position: (mysql-bin.000001, 1902), gtid-set: 09bec856-ba95-11ea-850a-58f2b4af5188:1-8], endLocation: [position: (mysql-bin.000001, 2026), gtid-set: ]: execute statement failed: ALTER TABLE `all_mode`.`t1` ADD COLUMN (`t6` INT, `t7` INT)",
                                "RawCause": "Error 8200: Unsupported multi schema change",

4. Versions of the cluster

   • DM version (run dmctl -V or dm-worker -V or dm-master -V):

     master

[csuzhangxc]

alter table t1 add column t6 int, add column t7 int; should have been split to

alter table t1 add column t6 int;
alter table t1 add column t7 int;

but not split ALTER TABLE `all_mode`.`t1` ADD COLUMN (`t6` INT, `t7` INT), right?

[lance6716]

alter table t1 add column t6 int, add column t7 int; should have been split to

alter table t1 add column t6 int;
alter table t1 add column t7 int;

but not split ALTER TABLE `all_mode`.`t1` ADD COLUMN (`t6` INT, `t7` INT), right?

Yes. I think DM should split ADD COLUMN (xx, xx) same way as ADD COLUMN xx, ADD COLUMN xx