This topic describes how to migrate data between PolarDB for Oracle clusters by using Data Transmission Service (DTS).
Prerequisites
- The source and destination PolarDB for Oracle clusters are created. For more information, see Create a PolarDB for Oracle cluster.
- The value of the wal_level parameter is set to logical for the source PolarDB for Oracle cluster. This setting ensures that logical encoding is supported in write-ahead logging (WAL). For more information, see Configure cluster parameters.
Limits
Category | Description |
---|---|
Limits on the source database |
|
Other limits |
|
Billing
Migration type | Instance configuration fee | Internet traffic fee |
---|---|---|
Schema migration and full data migration | Free of charge. | Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Billing overview. |
Incremental data migration | Charged. For more information, see Billing overview. |
Migration types
Migration type | Description |
---|---|
Schema migration | DTS migrates the schemas of objects to the destination database. DTS supports schema
migration for the following types of objects: table, view, synonym, trigger, stored
procedure, stored function, package, and user-defined type.
Note In this scenario, DTS does not support triggers. We recommend that you delete the
triggers of the source database to prevent data inconsistency caused by triggers.
For more information about, see Configure a data synchronization task for a source database that contains a trigger.
|
Full data migration | DTS migrates historical data of objects from the source database to the destination
database.
Note During schema migration and full data migration, do not perform DDL operations on
the objects to be migrated. Otherwise, the objects may fail to be migrated.
|
Incremental data migration | DTS retrieves redo log files from the source database. Then, DTS migrates incremental
data from the source database to the destination database by using the redo log files.
Incremental data migration allows you to ensure service continuity when you migrate data between PolarDB for Oracle clusters. |
SQL operations that can be incrementally migrated
Operation type | SQL statement |
---|---|
DML | INSERT, UPDATE, and DELETE |
Permissions required for database accounts
Database | Required permission |
---|---|
Source PolarDB for Oracle cluster | Permissions of a privileged account |
Destination PolarDB for Oracle cluster | Permissions of the database owner
Important The database owner is specified when you create a database.
|
For more information about how to create a database account and grant permissions to the database account, see the following topic:
PolarDB for Oracle cluster: Create database accounts