This topic describes how to migrate full data from an Amazon RDS for Oracle instance to an ApsaraDB RDS for PPAS instance by using Data Transmission Service (DTS).
Prerequisites
- The Public accessibility option of the Amazon RDS for Oracle instance is set to Yes. The setting ensures that DTS can access the Amazon RDS for Oracle instance over the Internet.
- The database version of the Amazon RDS for Oracle instance is 9i, 10g, or 11g.
- An ApsaraDB RDS for PPAS instance is created. For more information, see Create an ApsaraDB RDS for PPAS instance.
- The available storage space of the ApsaraDB RDS for PPAS instance is larger than the total size of the data in the Amazon RDS for Oracle instance.
Precautions
- DTS uses read and write resources of the source and destination databases during full data migration. This may increase the loads of the database servers. If the database performance is unfavorable, the specification is low, or the data volume is large, database services may become unavailable. For example, DTS occupies a large amount of read and write resources in the following cases: a large number of slow SQL queries are performed on the source database, the tables have no primary keys, or a deadlock occurs in the destination database. Before you migrate data, evaluate the impact of data migration on the performance of the source and destination databases. We recommend that you migrate data during off-peak hours. For example, you can migrate data when the CPU utilization of the source and destination databases is less than 30%.
- The tables to be migrated in the source database must have PRIMARY KEY or UNIQUE constraints and all fields must be unique. Otherwise, the destination database may contain duplicate data records.
- If a data migration task fails, DTS attempts to resume the task. Before you switch your workloads to the destination instance, stop or release the data migration task. Otherwise, the data in the source database will overwrite the data in the destination instance after the task is resumed.
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 Pricing. |
Permissions required for database accounts
Database | Schema migration | Full data migration | Incremental data migration |
---|---|---|---|
Amazon RDS for Oracle | The owner permission on schemas | The owner permission on schemas | The permissions for the master user |
ApsaraDB RDS for PPAS | The read and write permissions on the destination database | The read and write permissions on the destination database | The read and write permissions on the destination database |
For more information about how to create and authorize database account, see the following topics:
- Amazon RDS for Oracle instance: CREATE USER and GRANT
- ApsaraDB RDS for PPAS instance: Create an account on an ApsaraDB RDS for PPAS instance.
Limits
- Amazon RDS for Oracle does not support incremental data migration because the dbcreator and sysadmin roles are unavailable in Amazon RDS.
- DTS does not synchronize data definition language (DDL) operations. We recommend that you do not perform DDL operations on the source database during full data migration.
- DTS does not migrate materialized views.
- During schema migration, reverse indexes and bitmap indexes are converted into common indexes. Partitioned indexes are converted into independent indexes on each partition in the ApsaraDB RDS for PPAS instance.
Data type mappings
For more information, see Data type mappings between heterogeneous databases.