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 cluster.
- The value of the wal_level parameter is set to logical for the source PolarDB for Oracle cluster. This setting ensures that logical decoding is supported in write-ahead logging (WAL). For more information, see Configure cluster parameters.
Limits
Category | Description |
---|---|
Limits on the source database |
|
Other limits |
|
Migration types
Migration type | Description |
---|---|
Schema migration | DTS migrates the schemas of the required objects from the source database to the destination
database. DTS supports schema migration for the following types of objects: table,
view, synonym, trigger, stored procedure, function, package, and user-defined type.
Note In this scenario, DTS is incompatible with triggers. We recommend that you delete
the triggers of the source database to prevent data inconsistency caused by triggers.
For more information, see Configure a data synchronization task for a source database that contains a trigger.
|
Full data migration | DTS migrates historical data of the required objects from the source database to the
destination database.
Note During schema migration and full data migration, we recommend that you do not perform
data definition language (DDL) operations on the required objects. 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.
Incremental data migration allows you to ensure service continuity when you migrate data between PolarDB for Oracle clusters. |
SQL operations that can be migrated
Operation type | SQL statements |
---|---|
DML | INSERT, UPDATE, and DELETE |
Permissions required for database accounts
Database | Required permissions |
---|---|
Source PolarDB for Oracle cluster | A privileged account |
Destination PolarDB for Oracle cluster | The permissions of the database owner
Notice You can specify the database owner when you create a database.
|
For more information about how to create and authorize a database account, see the following topics:
PolarDB for Oracle cluster: Create an account