Data Transmission Service:Migrate data from a Teradata database to an AnalyticDB for PostgreSQL instance

Prerequisites

• You can configure a data migration task for this scenario only in the DTS console of the new version.
• The version of the Teradata database is 17.
• The destination AnalyticDB for PostgreSQL instance is created. For more information, see Create an AnalyticDB for PostgreSQL instance.
• The available storage space of the destination AnalyticDB for PostgreSQL instance is larger than the total size of the data in the Teradata database.

Limits

Billing

Migration types

• Schema migration

  DTS migrates the schemas of required objects from the source database to the destination database.

  Warning Teradata and AnalyticDB for PostgreSQL are heterogeneous databases. Their data types do not have one-to-one correspondence. We recommend that you evaluate the impact of data type conversion on your business. For more information, see Data type mappings between heterogeneous databases.
• Full data migration

  DTS migrates historical data of required objects from the source database to the destination database.

Permissions required for database accounts

• Self-managed Teradata database: Adding Permissions
• AnalyticDB for PostgreSQL instance: Create a database account and Manage users and permissions

Procedure

1. Go to the Data Migration page of the new DTS console.
   Note You can also log on to the Data Management (DMS) console. In the top navigation bar, click DTS.
2. In the upper-left corner of the page, select the region in which the data migration instance resides.
   
3. Click Create Task. On the page that appears, configure the source and destination databases.
   Warning After you select the source and destination instances, we recommend that you read the limits displayed at the top of the page. This helps you create and run the data migration task.

   Section	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify a descriptive name that makes it easy to identify. You do not need to use a unique task name.
   Source Database	Database Type	Select Teradata.
   	Access Method	Select Self-managed Database with Public IP Address. Note If your source database is a self-managed database, you must deploy the network environment for the database. For more information, see Preparation overview.
   	Instance Region	Select the region where the Teradata database resides.
   	Hostname or IP Address	Enter the endpoint that is used to access the Teradata database. In this example, enter the public IP address.
   	Port Number	Enter the service port number of the Teradata database. The default port number is 1025.
   	Database Account	Enter the account of the Teradata database. 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.
   Destination Database	Database Type	Select AnalyticDB for PostgreSQL.
   	Access Method	Select Alibaba Cloud Instance.
   	Instance Region	Select the region where the destination AnalyticDB for PostgreSQL instance resides.
   	Instance ID	Select the ID of the destination AnalyticDB for PostgreSQL instance.
   	Database Name	Enter the name of the destination database in the AnalyticDB for PostgreSQL instance.
   	Database Account	Enter the database account of the destination AnalyticDB for PostgreSQL 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.

4. If a whitelist is configured for your self-managed database, you must add the CIDR blocks of DTS servers to the whitelist. Then, click Test Connectivity and Proceed.
   Warning

   • If the source or destination database instance is an Alibaba Cloud database instance, such as an ApsaraDB RDS for MySQL or ApsaraDB for MongoDB instance, or is a self-managed database hosted on Elastic Compute Service (ECS), DTS automatically adds the CIDR blocks of DTS servers to the whitelist of the database instance or ECS security group rules. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases. If the source or destination database is a self-managed database on data centers or is from other cloud service providers, you must manually add the CIDR blocks of DTS servers to allow DTS to access the database.
   • If the CIDR blocks of DTS servers are automatically or manually added to the whitelist of the database instance or ECS security group rules, security risks may arise. Therefore, before you use DTS to migrate data, you must understand and acknowledge the potential risks and take preventive measures, including but not limited to the following measures: enhance the security of your account and password, limit the ports that are exposed, authenticate API calls, regularly check the whitelist or ECS security group rules and forbid unauthorized CIDR blocks, or connect the database to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.
   • After the DTS task is completed or released, we recommend that you manually detect and remove the added CIDR blocks from the whitelist of the database instance or ECS security group rules.
5. Configure objects to migrate and advanced settings.
   • Basic Settings

     Parameter	Description
     Task Stages	Select both Schema Migration and Full Data Migration. Note In this scenario, DTS does not support incremental data migration. To ensure data consistency, we recommend that you do not write data to the source instance during data migration.
     Processing Mode of Conflicting Tables	Precheck and Report Errors: checks whether the destination database contains tables that have the same names as tables in the source database. If the source and destination databases do not contain identical table names, the precheck is passed. Otherwise, an error is returned during precheck and the data migration task cannot be started. Note You can use the object name mapping feature to rename the tables that are migrated to the destination database. You can use this feature if the source and destination databases contain identical table names and the tables in the destination database cannot be deleted or renamed. For more information, see Map object names. Ignore Errors and Proceed: skips the precheck for identical table names in the source and destination databases. Warning If you select Ignore Errors and Proceed, data inconsistency may occur and your business may be exposed to potential risks. If the source and destination databases have the same schema, DTS does not migrate data records that have the same primary keys as data records in the destination database. If the source and destination databases have different schemas, only specific columns are migrated or the data migration task fails.
     Select Objects	Select one or more objects from the Source Objects section and click the icon to add the objects to the Selected Objects section.
     Rename Databases and Tables	To rename an object that you want to migrate to the destination instance, right-click the object in the Selected Objects section. For more information, see Map the name of a single object. To rename multiple objects at a time, click in the upper-right corner of the Selected Objects section. For more information, see Map multiple object names at a time. Note 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.
     Filter data	You can specify WHERE conditions to filter data. For more information, see Use SQL conditions to filter data.

   • Advanced Settings

     Parameter	Description
     Set Alerts	Specify whether to set alerts for the data migration task. If the task fails or the migration latency exceeds the threshold, the alert contacts will receive notifications. Select No if you do not want to set alerts. Select Yes to set alerts. In this case, you must also set the alert threshold and alert contacts.
     Retry Time for Failed Connections	Specify the retry time range for failed connections. Valid values: 10 to 720. Unit: minutes. Default value: 720. We recommend that you set the retry time range to more than 30 minutes. If DTS reconnects to the source and destination databases within the specified time range, DTS resumes the data synchronization task. Otherwise, the data synchronization task fails. Note If an instance serves as the source or destination database of multiple data synchronization tasks, the value that is set later takes precedence. When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time range based on your business needs. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.
     Capitalization of Object Names in Destination Instance	Specify the capitalization of database names, table names, and column names in the destination instance. By default, DTS default policy is selected. You can select other options to make sure that the capitalization of object names is consistent with that of the source or destination database. For more information, see Specify the capitalization of object names in the destination instance.

6. Specify the primary key columns and distribution keys of the tables that you want to migrate to the AnalyticDB for PostgreSQL instance.
   
7. Click Next: Save Task Settings and Precheck in the lower part of the page.
   Note

   • Before you can start the data migration task, DTS performs a precheck. 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.
8. Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.
9. On the Purchase Instance page, specify the Instance Class parameter for the data migration instance. The following table describes the parameter.

   Section	Parameter	Description
   Parameters	Instance Class	DTS provides various migration specifications. The migration speed varies based on the migration specifications that you select based on your business requirements. For more information, see Specifications of data migration instances.

10. Read and select Data Transmission Service (Pay-as-you-go) Service Terms.
11. Click Buy and Start to start the data migration task. You can view the progress of the task in the task list.