Migrate from Amazon RDS for Oracle to ApsaraDB RDS for MySQL - Data Transmission Service

Use DTS to migrate data from an Amazon RDS for Oracle instance to an ApsaraDB RDS for MySQL instance. DTS supports schema migration, full data migration, and incremental data migration, enabling seamless database migration without application downtime.

Prerequisites

Set Public accessibility to Yes to allow DTS to connect to the Amazon RDS for Oracle instance over the internet.
The Amazon RDS for Oracle instance must be version 9i, 10g, 11g, 12c, or later (non-multitenant architecture).
The ApsaraDB RDS for MySQL instance must be version 5.6 or 5.7.
The ApsaraDB RDS for MySQL instance must have at least twice the storage space of the objects to be migrated.

Note
Binary logs generated during migration occupy storage space and are automatically deleted after migration completes.
Before you perform a data migration, we recommend that you understand the capabilities and limitations of DTS for Oracle sources and use ADAM to perform a database evaluation. This ensures a smooth cloud migration. For more information, see Limitations and preparations for Oracle databases and Overview of database evaluation.

Usage notes

During a full data migration, DTS consumes read and write resources on the source and destination databases, increasing their load. If your databases have poor performance, low specifications, or high workloads (for example, if the source database has many slow SQL queries or tables without primary keys, or if deadlocks occur in the destination database), the increased load can strain your databases or even cause service interruptions. Perform the data migration during off-peak hours, such as when the CPU utilization of both databases is below 30%.
If a source table lacks a primary key or a unique constraint and contains non-unique data, duplicate data may be created in the destination database.
For columns with the FLOAT or DOUBLE data type, DTS reads their values by using the ROUND(COLUMN,PRECISION) function. If the precision is not explicitly defined, DTS migrates FLOAT values with a precision of 38 digits and DOUBLE values with a precision of 308 digits. Verify that these precisions meet your business requirements.
If a source database name violates ApsaraDB RDS naming conventions, you must create a compliant database in the destination instance before configuring the task. Otherwise, DTS creates the database automatically.

Note
For more information about naming conventions and how to create a database, see Create a database and accounts.
If a data migration task fails, DTS automatically attempts to resume it. Before you switch your business workloads to the destination instance, make sure to stop or release the task. This prevents an automatically resumed task from overwriting data in the destination instance with data from the source database.

Billing

Migration type	Task configuration fee	Internet traffic fee
Schema migration and full data migration	Free of charge.	DTS charges an Internet traffic fee when the Access Method of the destination database is set to Public IP Address. Billing overview.
Incremental data migration	Charged. Billing overview.

Migration types

Schema migration

DTS migrates tables, indexes, constraints, and sequences. Views, synonyms, triggers, stored procedures, functions, packages, and user-defined types are not supported.
Full data migration

DTS migrates all existing data from the source to the destination instance.
Incremental data migration

After full data migration, DTS captures incremental updates from the source redo log and synchronizes them to the destination. This enables seamless migration without application interruption.

Supported SQL operations

INSERT, DELETE, and UPDATE
CREATE TABLE

Note
Incremental data migration does not support partitioned tables or tables whose definitions include a function.
ALTER TABLE (limited to ADD COLUMN, DROP COLUMN, RENAME COLUMN, and ADD INDEX)
DROP TABLE
RENAME TABLE, TRUNCATE TABLE, and CREATE INDEX

Database account permissions

Database	Schema migration	Full data migration	Incremental data migration
Amazon RDS for Oracle	Schema owner permissions	Schema owner permissions	Master user permissions
ApsaraDB RDS for MySQL	Read and write permissions for the destination database	Read and write permissions for the destination database	Read and write permissions for the destination database

Create a database account and grant permissions:

Amazon RDS for Oracle: CREATE USER and GRANT.
ApsaraDB RDS for MySQL: Create an account and Modify account permissions.

Data type mapping

Data type mapping for heterogeneous databases.

Before you begin

Log on to the Amazon RDS Management Console.
Go to the Basic Information page of the Amazon RDS for Oracle instance.
In the Security group rules section, click the security group name of the inbound rule.
On the Security Groups page, add the DTS server IP addresses for the corresponding region to an inbound rule. IP address ranges are listed in Whitelist DTS server IP addresses.
For the inbound rule, select Custom TCP Rule for Type, enter 1521 for Port Range, select Custom for Source, enter the DTS server IP addresses, enter dts for Description, and click Save.
Note
- Add only the CIDR blocks for DTS servers in the destination database's region. For example, if your source database is in the Singapore region and your destination database is in the China (Hangzhou) region, you only need to add the CIDR blocks for DTS servers in the China (Hangzhou) region.
- You can add multiple CIDR blocks to a single rule.
- For more information, see the official AWS documentation or contact AWS Support.

Configure log settings for the Amazon RDS for Oracle instance. Skip this step if you do not need incremental data migration.

If your Amazon RDS for Oracle instance is version 12c or later (non-multitenant architecture), perform the following steps to configure its logs:

Connect to the Amazon RDS for Oracle database by using a master user account and the SQL*Plus tool.

Enable archive and supplemental logging.

Log type

Procedure

Archive logging

Run the following command to check whether archive logging is enabled:
```
SELECT LOG_MODE FROM v$database;
```
View and set the retention period for archived logs.

Note
Retain archived logs for at least 72 hours. The following example sets 72 hours.
```
exec rdsadmin.rdsadmin_util.show_configuration;
exec rdsadmin.rdsadmin_util.set_configuration('archivelog retention hours', 72); 
```

Supplemental logging

Based on your business requirements, enable supplemental logging at the database level or table level:

Enable database-level supplemental logging

Run the following command to check whether database-level supplemental logging is enabled:

SELECT supplemental_log_data_min, supplemental_log_data_pk, supplemental_log_data_ui FROM v$database;

Enable primary key and unique key supplemental logging at the database level.

exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD', 'PRIMARY KEY');
exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD', 'UNIQUE');

Enable table-level supplemental logging by using one of the following methods:
- Enable supplemental logging for all columns of a table.
```
exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD', 'ALL');
```
- Enable primary key supplemental logging at the table level.
```
exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD', 'PRIMARY KEY');
```

Grant fine-grained permissions to the Amazon RDS for Oracle database account.

Grant fine-grained permissions

Permissions

# This script creates a database account named RDSDT_DTSACCT and grants it the required permissions.
create user RDSDT_DTSACCT IDENTIFIED BY RDSDT_DTSACCT;
grant create session to RDSDT_DTSACCT;
grant connect to RDSDT_DTSACCT;
grant resource to RDSDT_DTSACCT;
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$LOGMNR_LOGS','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('ALL_OBJECTS','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('ALL_TAB_COLS','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('DBA_REGISTRY','RDSDT_DTSACCT','SELECT');
grant select any table to RDSDT_DTSACCT;
grant select any transaction to RDSDT_DTSACCT;
-- v$log privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$LOG','RDSDT_DTSACCT','SELECT');
-- v$logfile privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$LOGFILE','RDSDT_DTSACCT','SELECT');
-- v$archived_log privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$ARCHIVED_LOG','RDSDT_DTSACCT','SELECT');
-- v$parameter privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$PARAMETER','RDSDT_DTSACCT','SELECT');
-- v$database privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$DATABASE','RDSDT_DTSACCT','SELECT');
-- v$active_instances privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$ACTIVE_INSTANCES','RDSDT_DTSACCT','SELECT');
-- v$instance privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$INSTANCE','RDSDT_DTSACCT','SELECT');
-- v$logmnr_contents privileges
exec rdsadmin.rdsadmin_util.grant_sys_object('V_$LOGMNR_CONTENTS','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('USER$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('OBJ$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('COL$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('IND$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('ICOL$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('CDEF$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('CCOL$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('TABPART$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('TABSUBPART$','RDSDT_DTSACCT','SELECT');
exec rdsadmin.rdsadmin_util.grant_sys_object('TABCOMPART$','RDSDT_DTSACCT','SELECT');
grant LOGMINING TO RDSDT_DTSACCT;
grant EXECUTE_CATALOG_ROLE to RDSDT_DTSACCT;
exec rdsadmin.rdsadmin_util.grant_sys_object('DBMS_LOGMNR','RDSDT_DTSACCT','EXECUTE');
grant select on v$database to rdsdt_dtsacct;
grant select on dba_objects to rdsdt_dtsacct;
grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct;
grant select on dba_tab_cols to rdsdt_dtsacct;
grant select_catalog_role TO rdsdt_dtsacct;

If your Amazon RDS for Oracle instance is version 9i, 10g, or 11g, perform the following steps to configure its logs:
1. Connect to the Amazon RDS for Oracle database by using a master user account and the SQL*Plus tool.
2. Run the archive log list; command to verify the Amazon RDS for Oracle instance is in ARCHIVELOG mode.
  
  Note
  If the instance is in NOARCHIVELOG mode, enable ARCHIVELOG mode. Managing Archived Redo Logs.
3. Enable force logging.
```
exec rdsadmin.rdsadmin_util.force_logging(p_enable => true);
```
4. Enable primary key supplemental logging.
```
begin rdsadmin.rdsadmin_util.alter_supplemental_logging(p_action => 'ADD',p_type => 'PRIMARY KEY');end;/
```
5. Enable unique key supplemental logging.
```
begin rdsadmin.rdsadmin_util.alter_supplemental_logging(p_action => 'ADD',p_type => 'UNIQUE');end;/
```
6. Set the retention period for archived logs.
```
begin rdsadmin.rdsadmin_util.set_configuration(name => 'archivelog retention hours', value => '24');end;/
```
7. Set the retention period for archived logs.
  
  Note
  Retain archived logs for at least 24 hours.
8. Commit the changes.
```
commit;
```

Procedure (new console)

Navigate to the migration task list page for the destination region using one of the following methods.
From the DTS console
1. Log on to the Data Transmission Service (DTS) console.
2. In the navigation pane on the left, click Data Migration.
3. In the upper-left corner of the page, select the region where the migration instance is located.
From the DMS console

Note
The actual operations may vary based on the mode and layout of the DMS console. For more information, see Simple mode console and Customize the layout and style of the DMS console.
1. Log on to the Data Management (DMS) console.
2. In the top menu bar, choose Data + AI > Data Transmission (DTS) > Data Migration.
3. To the right of Data Migration Tasks, select the region where the migration instance is located.
Click Create Task to navigate to the task configuration page.

Configure the source and destination databases.

Warning

After you select the source and destination instances, we recommend that you carefully read the limits displayed at the top of the page. Otherwise, the task may fail or data inconsistency may occur.

Category	Parameter	Description
N/A	Task Name	DTS automatically generates a task name. We recommend that you specify a descriptive name for easy identification. The name does not need to be unique.
Source Database	Select a DMS database instance.	You can choose whether to use an existing instance, as needed. If you use an existing instance, the database information below is automatically filled in. You do not need to enter it again. If you do not use an existing instance, you must configure the database information below. Note In the DMS console, you can click Add DMS Database Instance to register a database with DMS. For more information, see ApsaraDB Data Ingestion and Register a database hosted on a third-party cloud service or a self-managed database. In the DTS console, you can register a database with DTS on the Database Connections page or the new configuration page. For more information, see Manage database connections.
	Database Type	Select Oracle.
	Connection Type	Select Public IP Address.
	Instance Region	Select the region of the source Amazon RDS for Oracle database. Note If the region is not listed, select the geographically closest region.
	Domain Name or IP	Enter the endpoint of the Amazon RDS for Oracle database. Note You can find the connection information on the Basic Information page of the Amazon RDS for Oracle instance.
	Port Number	Enter the service port of the Amazon RDS for Oracle database. Default: 1521.
	Oracle Type	Non-RAC Instance: If you select this option, you must also specify the SID. RAC or PDB Instance: If you select this option, you must also specify the Service Name. In this example, Non-RAC Instance is selected.
	Database Account	Enter the database account of the source Amazon RDS for Oracle database. Required permissions are listed in Permissions required for database accounts.
	Database Password	Enter the password for the database account.
Destination Database	Select a DMS database instance.	You can choose whether to use an existing instance, as needed. If you use an existing instance, the database information below is automatically filled in. You do not need to enter it again. If you do not use an existing instance, you must configure the database information below. Note In the DMS console, you can click Add DMS Database Instance to register a database with DMS. For more information, see ApsaraDB Data Ingestion and Register a database hosted on a third-party cloud service or a self-managed database. In the DTS console, you can register a database with DTS on the Database Connections page or the new configuration page. For more information, see Manage database connections.
	Database Type	Select MySQL.
	Connection Type	Select Alibaba Cloud Instance.
	Instance Region	Select the region of the destination RDS for MySQL instance.
	RDS Instance ID	Select the destination RDS for MySQL instance ID.
	Database Account	Enter the database account for the destination RDS for MySQL instance. Required permissions are listed in Permissions required for database accounts.
	Database Password	Enter the password for the database account.
	Connection Method	Select Non-encrypted or SSL-encrypted based on your database requirements. If you set this parameter to SSL-encrypted, you must enable SSL encryption for the RDS for MySQL instance beforehand. For more information, see Quickly enable SSL encryption using a cloud certificate.

After you complete the configuration, click Test Connectivity and Proceed at the bottom of the page. In the CIDR Blocks of DTS Servers dialog box that appears, click Test Connectivity.

Note
Ensure that the IP address segments of the DTS service are automatically or manually added to the security settings of the source and destination databases to allow access from DTS servers. For more information, see Add DTS server IP addresses to a whitelist.

Configure the task objects.

On the Configure Objects page, configure the objects that you want to migrate.

Parameter	Description
Migration Types	If you only need to perform a full migration, select both Schema Migration and Full Data Migration. To perform a migration with no downtime, select Schema Migration, Full Data Migration, and Incremental Data Migration. Note If you do not select Schema Migration, you must ensure that a database and tables to receive the data exist in the destination database. You can also use the object name mapping feature in the Selected Objects box as needed. If you do not select Incremental Data Migration, do not write new data to the source instance during data migration to ensure data consistency.
Processing Mode of Conflicting Tables	Precheck and Report Errors: Checks whether tables with the same names exist in the destination database. If no tables with the same names exist, the precheck is passed. If tables with the same names exist, an error is reported during the precheck, and the data migration task does not start. Note If a table in the destination database has the same name but cannot be easily deleted or renamed, you can change the name of the table in the destination database. For more information, see Object name mapping. Ignore Errors and Proceed: Skips the check for tables with the same names. Warning Selecting Ignore Errors and Proceed may cause data inconsistency and business risks. For example: If the table schemas are consistent and a record in the destination database has the same primary key value as a record in the source database: During full migration, DTS keeps the record in the destination database. The record from the source database is not migrated. During incremental migration, DTS does not keep the record in the destination database. The record from the source database overwrites the record in the destination database. If the table schemas are inconsistent, only some columns of data may be migrated, or the migration may fail. Proceed with caution.
Source Objects	In the Source Objects box, click the objects to migrate, and then click to move them to the Selected Objects box. Note You can select objects at the database, table, and column levels.
Selected Objects	To change the name of a single migration object in the target instance, right-click the object in the Selected Objects box. For more information, see Map individual schema, table, and column names. To change the names of multiple migration objects in the target instance, click Selected Objects in the upper-right corner of the Batch Edit box. For more information, see Map multiple schema, table, and column names. Note If you use the object name mapping feature, other objects that depend on the renamed object may fail to migrate. To filter data with a WHERE clause, right-click the table in the Selected Objects box and set the filter condition. Filter task data by using SQL conditions. To select SQL operations for incremental data migration at the database or table level, right-click the migration object in the Selected Objects box and select the desired SQL operations in the dialog box that appears.

Click Next: Advanced Settings to configure advanced parameters.

Parameter	Description
Dedicated Cluster for Task Scheduling	DTS schedules tasks on a shared cluster by default. You can purchase a dedicated cluster to run migration tasks. What is a DTS dedicated cluster?.
Retry Time for Failed Connections	After the migration task starts, if the connection to the source or destination database fails, DTS reports an error and immediately begins to retry the connection. The default retry duration is 720 minutes. You can customize the retry time to a value from 10 to 1440 minutes. We recommend that you set the duration to more than 30 minutes. If DTS reconnects to the source and destination databases within the specified duration, the migration task automatically resumes. Otherwise, the task fails. Note For multiple DTS instances that share the same source or destination, the network retry time is determined by the setting of the last created task. Because you are charged for the task during the connection retry period, we recommend that you customize the retry time based on your business needs, or release the DTS instance as soon as possible after the source and destination database instances are released.
Retry Time for Other Issues	After the migration task starts, if a non-connectivity issue, such as a DDL or DML execution exception, occurs in the source or destination database, DTS reports an error and immediately begins to retry the operation. The default retry duration is 10 minutes. You can customize the retry time to a value from 1 to 1440 minutes. We recommend that you set the duration to more than 10 minutes. If the related operations succeed within the specified retry duration, the migration task automatically resumes. Otherwise, the task fails. Important The value of Retry Time for Other Issues must be less than the value of Retry Time for Failed Connections.
Enable Throttling for Full Data Migration	During full migration, DTS consumes read and write resources on the source and destination databases, which may increase the database load. If required, you can enable throttling for the full migration task. You can set Queries per second (QPS) to the source database, RPS of Full Data Migration, and Data migration speed for full migration (MB/s) to reduce the load on the destination database. Note This configuration item is available only if you select Full Data Migration for Migration Types. You can also adjust the full migration speed after the migration instance is running.
Enable Throttling for Incremental Data Migration	If required, you can also choose to set speed limits for the incremental migration task. You can set RPS of Incremental Data Migration and Data migration speed for incremental migration (MB/s) to reduce the load on the destination database. Note This configuration item is available only if you select Incremental Data Migration for Migration Types. You can also adjust the incremental migration speed after the migration instance is running.
Environment Tag	Select an environment tag to identify the instance. Not required for this example.
Actual Write Code	Select the character encoding for data written to the destination.
Configure ETL	Choose whether to enable the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values: Yes: Enables the ETL feature. Enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task. No: Disables the ETL feature.
Monitoring and Alerting	Select whether to set alerts and receive alert notifications based on your business needs. No: Does not set an alert. Yes: Configure alerts by setting an alert threshold and an alert notifications. If a migration fails or the latency exceeds the threshold, the system sends an alert notification.

Click Next: Data Validation to configure a data validation task.

For more information about the data validation feature, see Configure data validation.

Save the task and run a precheck.
- To view the parameters for configuring this instance when you call the API operation, move the pointer over the Next: Save Task Settings and Precheck button and click Preview OpenAPI parameters in the bubble that appears.
- If you do not need to view or have finished viewing the API parameters, click Next: Save Task Settings and Precheck at the bottom of the page.
Note
- Before the migration task starts, DTS performs a precheck. The task starts only after it passes the precheck.
- If the precheck fails, click View Details next to the failed check item, fix the issue based on the prompt, and then run the precheck again.
- If a warning is reported during the precheck:
  
  For check items that cannot be ignored, click View Details next to the failed item, fix the issue based on the prompt, and then run the precheck again.
  
  For check items that can be ignored, you can click Confirm Alert Details, Ignore, OK, and Precheck Again to skip the alert item and run the precheck again. If you choose to ignore a warning, it may cause issues such as data inconsistency and pose risks to your business.

Purchase the instance.

When the Success Rate is 100%, click Next: Purchase Instance.

On the Purchase page, select the link specification for the data migration instance. For more information, see the following table.

Category	Parameter	Description
New Instance Class	Resource Group Settings	Select the resource group to which the instance belongs. The default value is default resource group. For more information, see What is Resource Management?
New Instance Class	Instance Class	DTS provides migration specifications with different performance levels. The link specification affects the migration speed. You can select a specification based on your business scenario. For more information, see Data migration link specifications.

After the configuration is complete, read and select Data Transmission Service (Pay-as-you-go) Service Terms.
Click Buy and Start. In the OK dialog box that appears, click OK.

You can view the progress of the migration task on the Data Migration Tasks list page.
Note
- If the migration task does not include incremental migration, it stops automatically after the full migration is complete. After the task stops, its Status changes to Completed.
- If the migration task includes incremental migration, it does not stop automatically. The incremental migration task continues to run. While the incremental migration task is running, the Status of the task is Running.

Procedure (old console)

Log on to the DTS console.

Note
If you are automatically redirected to the Data Management (DMS) console, you can click the icon in the lower-right corner and then click to return to the classic DTS console.
In the left-side navigation pane, click Data Migration.
At the top of the Migration Tasks page, select the region of the destination cluster.
In the upper-right corner of the page, click Create Data Migration Task.