The migration service can migrate data from a local database to ApsaraDB, or migrate an ApsaraDB instance to another instance. ApsaraDB includes a Data Transfer Service (DTS) tool to facilitate quick database migration.

DTS is a cloud data transfer service for efficient instance migration from local databases to the cloud, and between RDS instances. For more information, see DTS product overview.

DTS provides three migration modes, that is, structure migration, full migration, and incremental migration. The detailed introduction is as follows:

  • Structure migration: DTS migrates the structure definitions of migration objects to the target instance. Currently, this mode can migrate tables, views, triggers, stored procedures, and stored functions.

  • Full migration: DTS migrates all existing data in the source database migration objects to the target instance.

    To guarantee data consistency, non-transaction tables that do not have a Primary Key are locked during full migration. Locked tables cannot be written to, and the duration of the lock depends on the volume of data in a table. The locks are released only after the non-transaction tables without a Primary Key are fully migrated.
  • Incremental migration: DTS synchronizes data changes made in the migration process to the target instance.

    If a DDL operation is performed during data migration, the related structure changes are not synchronized to the target instance.