DDL synchronization between Oracle tenants of OceanBase Database

Supported DDL operations

• CREATE TABLE

   You can create partitioned tables but cannot use `CREATE TABLE AS SELECT` to create tables. Partitions and subpartitions are supported. You can create partitions and subpartitions by using HASH, RANGE, or LIST partitioning.
  

• DROP TABLE

• TRUNCATE TABLE

• RENAME TABLE and ALTER TABLE RENAME

• ALTER TABLE ADD COLUMN

• ALTER TABLE MODIFY COLUMN

  Notice

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

• create index

• drop index

• Adding or dropping comments on tables or columns

Limitations

• If a table to be synchronized involves DDL operations that are not supported, the migration project may fail and unrecoverable data exceptions may be caused.

• Frequent DDL operations on a table are not supported. After the store finishes a DDL operation, which can be determined based on the timestamp, it proceeds to the next DDL operation. Otherwise, the store may exit unexpectedly or cause unrecoverable data exceptions.

• Make sure that no DDL operations are performed before you create a store and when a store is being started. If log pulling is involved, make sure that no DDL operations are performed during the period from the start time when logs are pulled to the current time. Otherwise, the store may exit unexpectedly or cause unrecoverable data exceptions.

• The table names before and after the RENAME TABLE statement must be both included or both not included in the list of tables to be synchronized.

• A table creation DDL operation that involves the case when index statement cannot be synchronized.

• If you enable DDL synchronization, the index dropped in the source database by executing the drop index statement is also dropped in the destination database. This may cause index loss in the destination database.