DDL synchronization between MySQL-compatible tenants of OceanBase Database

This topic introduces the DDL statements supported for synchronization between MySQL-compatible tenants of OceanBase Database.

Supported DDL statements

• ALTER TABLE ADD COLUMN

• ALTER TABLE MODIFY COLUMN

  Notice

  You can increase the column length, but you cannot modify the column type.

• ALTER TABLE ALTER COLUMN SET DEFAULT and ALTER TABLE ALTER COLUMN DROP DEFAULT

• ALTER TABLE DROP COLUMN

• CREATE TABLE

  Notice

  CREATE TABLE AS SELECT is not supported.

• DROP TABLE

• TRUNCATE TABLE

• CREATE INDEX and ALTER TABLE ADD INDEX

• DROP INDEX and ALTER TABLE DROP INDEX

• RENAME TABLE and ALTER TABLE RENAME

Limitations

• If the tables to be synchronized involve unsupported DDL statements, the migration task may be interrupted, resulting in unrecoverable data inconsistencies.

• Frequent DDL operations on a single table are not supported. Perform the next DDL operation only after the Store has completed the current operation based on the log position. Otherwise, the Store may exit unexpectedly or cause unrecoverable data errors.

• Ensure that no DDL operations are performed for a period before you create a Store or while the Store is starting. If logs need to be pulled from an earlier point, ensure that no DDL operations are performed between the log pull point and the current time. Otherwise, the Store may exit unexpectedly or cause unrecoverable data errors.

• The table names before and after the RENAME TABLE operation must be present in the list of tables to be synchronized.