This topic describes how to migrate data from a PolarDB for Oracle cluster to a self-managed Oracle database by using Data Transmission Service (DTS).
Prerequisites
- The source PolarDB for Oracle cluster is 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 |
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Limits on the source database |
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Other limits |
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Special cases | If the self-managed Oracle database is deployed in a Real Application Cluster (RAC)
architecture and is connected to DTS over an Alibaba Cloud virtual private cloud (VPC),
you must connect the Single Client Access Name (SCAN) IP address of the Oracle RAC
and the virtual IP address (VIP) of each node to the VPC and configure routes. The
settings ensure that your DTS task can run as expected. For more information, see
Connect an on-premises database to Alibaba Cloud and Configure a route between DTS and Express Connect, VPN Gateway, or Smart Access Gateway.
Important When you configure the source Oracle database in the DTS console, you must enter the
SCAN IP address of the Oracle RAC in the Database Endpoint or IP Address field.
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Billing
Migration type | Instance configuration fee | Internet traffic fee |
---|---|---|
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 |
---|---|
Full data migration | DTS migrates historical data of objects from the source database to the destination
database.
Note During full data migration, we recommend that you do not perform DDL operations on
the required objects. Otherwise, the objects may fail to be migrated.
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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 perform data migration. |
SQL operations that can be incrementally migrated
Operation type | SQL statement |
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DML | INSERT, UPDATE, and DELETE |
Permissions required for database accounts
Database | Required permission |
---|---|
PolarDB for Oracle cluster | Permissions of a privileged account |
Self-managed Oracle database | Permissions of the schema owner |
For more information about how to create and grant permissions to a database account, see the following topics:
- PolarDB for Oracle cluster: Create database accounts
- Self-managed Oracle database: CREATE USER and GRANT