Synchronize DDL operations from an OBSharding database to the Oracle compatible mode of OceanBase Database

Supported DDL operations

• ALTER TABLE ADD COLUMN: You must specify a default value.

• ALTER TABLE MODIFY COLUMN: You can only increase the length of a column.

• CREATE INDEX or ALTER TABLE ADD INDEX

• DROP INDEX or ALTER TABLE DROP INDEX

Limitations

All physical schemas under the default logical table must be consistent. If there are inconsistencies (only some tables are modified), data synchronization will fail due to data inconsistency.

• ALTER TABLE ADD COLUMN: You must specify a default value.

• ALTER TABLE MODIFY COLUMN: This operation cannot handle the following special case.

  Originally, a column was nullable. You modify the column to be non-nullable and perform a rollback. In this case, if the data is null and the target database does not allow null values, data synchronization will fail.

  For this scenario, you can first execute the DDL operation on the target database to allow null values, and then automatically synchronize the subsequent MODIFY DDL operation.