OceanBase Migration Service (OMS) Community Edition supports real-time data transmission between OceanBase Database Community Edition and different types of data sources, such as MySQL, TiDB, and PostgreSQL, and supports data migration between MySQL tenants of OceanBase Database Community Edition.
Background information
OMS Community Edition supports online migration. Before you start a data migration task, you must configure the source and destination data sources to connect the server where OMS Community Edition is deployed to both the source and destination instances, and select the migration objects.
OMS Community Edition automatically executes all steps of a data migration task to copy objects, existing data, or incremental data from the source database or table to the destination database or table, and ensures real-time incremental synchronization from the source database to the destination database.
Supported migration task types
OMS Community Edition supports the following migration task types:
Migrate data from a MySQL database to OceanBase Database Community Edition
Migrate data from a Milvus database to OceanBase Database Community Edition
Migrate data between instances of OceanBase Database Community Edition
Migrate data from a TiDB database to OceanBase Database Community Edition
Migrate data from a PostgreSQL database to OceanBase Database Community Edition
Migrate data from a Qdrant database to OceanBase Database Community Edition
Note
For more information about the version restrictions on data sources, see Limitations.
Supported migration types
The following table describes the migration types supported by OMS Community Edition. For more information about each migration type, see the topic about creating a data migration task between the corresponding types of data sources in the "Data Migration" chapter.
| Migration type | Description |
|---|---|
| Schema migration | Migrates the definitions of data objects, such as tables, indexes, constraints, comments, and views, from the source database to the destination database. Temporary tables are automatically filtered out. If the source database is not an OceanBase database, OMS Community Edition performs format conversion and encapsulation based on the syntax definition and standard of the type of the destination tenant of OceanBase Database and then replicates the data to the destination database. |
| Full data migration | Migrates the existing data from tables in the source database to the corresponding tables in the destination database. On the Full Data Migration page, you can view information on the Tables, Table Indexes, and Migration Performance tabs. The status of a full data migration task changes to Completed only after the table objects and table indexes are migrated. On the Table Indexes page, you can click View Creation Syntax next to a table to view its index creation syntax. You can combine full data migration with incremental synchronization to ensure data consistency between the source and destination databases. If any objects fail to be migrated during full data migration, the causes of the failure are displayed. |
| Incremental synchronization | After incremental synchronization starts, OMS Community Edition synchronizes the data that has been changed (added, modified, or deleted) in the source database to the corresponding tables in the destination database. When services continuously write data to the source database, OMS Community Edition starts the incremental data pull module to pull incremental data from the source instance, parses and encapsulates the incremental data, and then stores the data. After that, OMS Community Edition starts the full data migration task. After the full data migration task is completed, OMS Community Edition starts the incremental data replay module to pull incremental data from the incremental data pull module. The incremental data is synchronized to the destination database after being filtered, mapped, and converted. |
| Full verification | After the full data migration and incremental data migration are completed, OMS Community Edition automatically initiates a full verification task to verify the data tables in the source and destination data sources. You can initiate custom data verification tasks during incremental data synchronization. If tables with inconsistent data are detected, you can choose to re-verify all data or only the inconsistent data in the tables. |
| Forward switchover | Forward switchover is an abstract and standard process of traditional system cutover and does not involve the switchover of application connections. This process includes a series of tasks that are performed by OMS Community Edition for application switchover in a data migration task. You must make sure that the entire forward switchover process is completed before the application connections are switched over to the destination database. Forward switchover is required for data migration. OMS Community Edition can ensure the completion of forward data migration in this process. You can start the Incr-Sync component for reverse incremental migration based on your business needs. The forward switchover process involves the following operations:
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| Reverse incremental migration | In business cutover scenarios, after the migration is completed, you can start an incremental synchronization task in a reverse direction. In other words, you can synchronize data from the destination database to the source database before the business database switchover. This way, data changes made in the destination database after the switchover are applied to the source business database in real time. |