ApsaraDB for OceanBase:Configure DDL/DML synchronization

Background

If you select Incremental Synchronization in the Select Migration Type or Select Synchronization Type step of a data migration or synchronization project, DML synchronization is supported by default. You can configure DML synchronization or DDL synchronization.

• DML synchronization: When you configure a data migration or synchronization project, you can specify a synchronization strategy for the DML SQL statements to be synchronized. Only those meeting the specified conditions will be synchronized to the destination. DML filtering applies to scenarios of migrating historical tables and transaction details tables.

• DDL synchronization: You can choose whether to synchronize DDL operations when you configure a data migration or synchronization project. DDL operations, such as CREATE TABLE, ALTER TABLE, DROP TABLE, and TRUNCATE TABLE, are synchronized to the destination only after you enable DDL synchronization. The DDL synchronization feature applies to long-term data migration and synchronization projects to significantly lower the O&M costs.

Limitations

• DML synchronization

  • DML filtering takes effect for the entire data migration or synchronization project.

  • Full data verification is not supported for a data migration project for which DML filtering is configured.

• DDL synchronization

  • Only DDL operations that are listed in the preceding section are supported.

  • If a table to be synchronized involves unsupported DDL operations, the data migration or synchronization project may be interrupted and unrecoverable data exceptions may arise.

  • Do not perform DDL operations for database or table schema changes in the schema migration/synchronization or full migration/synchronization phase. Otherwise, the data migration or synchronization project may be interrupted.

Procedure

1. Configure a data migration or synchronization project as prompted to the Select Migration Type or Select Synchronization Type step.

   For more information, see the topics about data migration or data synchronization projects of the corresponding data source types.

   

2. On the Select Migration Type or Select Synchronization Type page, select Incremental Synchronization. DML Synchronization is selected by default.

   

3. Click Custom configuration DDL/DML.

4. In the Custom configuration DDL/DML dialog box, select the DML or DDL operations to be synchronized.

   DML operations Insert, Delete, and Update are supported for synchronization. You can perform DML filtering as needed. For more information about the DDL operations that can be synchronized for different types of data migration or synchronization projects, see Supported DDL operations for synchronization. You can select DDL operations as needed.

   

5. In the Custom configuration DDL/DML dialog box, click OK.

6. On the Select Migration Type or Select Synchronization Type page, click Next and complete subsequent project settings as prompted.