Migrate full data from an Amazon RDS for Oracle instance to an ApsaraDB RDS for PPAS 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 instance will overwrite the data in the destination instance after the task is resumed.

Billing

Permissions required for database accounts

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 conversion

For more information, see Data type mappings between heterogeneous databases.

Before you begin

1. Log on to the Amazon RDS Management Console.
2. Go to the Basic information page of the Amazon RDS for Oracle instance.
3. In the Security group rules section, click the name of the security group corresponding to the existing inbound rule.
   
4. On the Security groups page, click the Inbound tab in the Security group section. On the Inbound tab, click Edit to add the CIDR blocks of DTS servers in the corresponding region to the inbound rule. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
   

   Note

   • You need to add only the CIDR blocks of DTS servers that reside in the same region as the destination database. For example, the source database resides in the Singapore (Singapore) region and the destination database resides in the China (Hangzhou) region. You need to add only the CIDR blocks of DTS servers that reside in the China (Hangzhou) region.
   • You can add all of the required CIDR blocks to the inbound rule at a time.

Procedure

1. Log on to the DTS console.
2. In the left-side navigation pane, click Data Migration.
3. At the top of the Migration Tasks page, select the region where the destination cluster resides.
   
4. In the upper-right corner of the page, click Create Migration Task.
5. Configure the source and destination databases.
   

   Section	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify an informative name for easy identification. You do not need to use a unique task name.
   Source Database	Instance Type	Select User-Created Database with Public IP Address.
   	Instance Region	If the instance type is set to User-Created Database with Public IP Address, you do not need to specify the instance region.
   	Database Type	Select Oracle.
   	Hostname or IP Address	Enter the endpoint that is used to access the Amazon RDS for Oracle instance. Note You can obtain the endpoint on the Basic Information page of the Amazon RDS for Oracle instance.
   	Port Number	Enter the service port number of the self-managed Oracle database. The default port number is 1521.
   	Instance Type	If you select Non-RAC Instance, you must specify the SID parameter. If you select RAC Instance, you must specify the Service Name parameter.
   	Database Account	Enter the database account of the Amazon RDS for Oracle instance. For information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password of the database account. Note After you specify the source database parameters, click Test Connectivity next to Database Password to verify whether the specified parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the source database parameters based on the check results.
   Destination Database	Instance Type	Select RDS Instance.
   	Instance Region	Select the region where the ApsaraDB RDS for PPAS instance resides.
   	RDS Instance ID	Select the ID of the ApsaraDB RDS for PPAS instance.
   	Database Name	Enter the name of the destination database.
   	Database Account	Enter the database account of the ApsaraDB RDS for PPAS instance. For information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password of the database account. Note After you specify the destination database parameters, click Test Connectivity next to Database Password to verify whether the specified parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the destination database parameters based on the check results.

6. In the lower-right corner of the page, click Set Whitelist and Next.
   Note DTS adds the CIDR blocks of DTS servers to the whitelist of the ApsaraDB RDS for PPAS instance. This ensures that DTS servers can connect to the ApsaraDB RDS for PPAS instance.
7. Select the migration types and the objects to be migrated.
   

   Setting	Description
   Select the migration types	Select Schema Migration and Full Data Migration. Note Amazon RDS for Oracle does not support incremental data migration because the dbcreator and sysadmin roles are unavailable in Amazon RDS. To ensure data consistency, we recommend that you do not write data to the Amazon RDS for Oracle instance during data migration.
   Select the objects to be migrated	Select one or more objects from the Available section and click the icon to move the objects to the Selected section. Note You can select columns, tables, or databases as the objects to be migrated. By default, after an object is migrated to the destination database, the name of the object remains unchanged. You can use the object name mapping feature to rename the objects that are migrated to the destination database. For more information, see Object name mapping. If you use the object name mapping feature to rename an object, other objects that are dependent on the object may fail to be migrated.
   Specify whether to rename objects	You can use the object name mapping feature to rename the objects that are migrated to the destination instance. For more information, see Object name mapping.
   Specify the retry time for failed connections to the source or destination database	By default, if DTS fails to connect to the source or destination database, DTS retries within the next 12 hours. You can specify the retry time based on your needs. If DTS reconnects to the source and destination databases within the specified time, DTS resumes the data migration task. Otherwise, the data migration task fails. Note When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time based on your business needs. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.

8. In the lower-right corner of the page, click Precheck.
   Note

   • Before you can start the data migration task, a precheck is performed. You can start the data migration task only after the task passes the precheck.
   • If the task fails to pass the precheck, you can click the icon next to each failed item to view details.
     • You can troubleshoot the issues based on the causes and run a precheck again.
     • If you do not need to troubleshoot the issues, you can ignore failed items and run a precheck again.
9. After the task passes the precheck, click Next.
10. In the Confirm Settings dialog box, specify the Channel Specification parameter and select Data Transmission Service (Pay-As-You-Go) Service Terms.
11. Click Buy and Start to start the data migration task.
    Note We recommend that you do not manually stop a data migration task. Otherwise, data migrated to the destination instance will be incomplete. You can wait until the data migration task automatically stops.

    
12. Switch your workloads to the ApsaraDB RDS for PPAS instance.