This topic describes how to synchronize data from a self-managed Oracle database to an AnalyticDB for PostgreSQL instance by using Data Transmission Service (DTS).

Prerequisites

  • The version number of the self-managed Oracle database is 9i, 10g, 11g, 12c, 18c, or 19c.
  • The self-managed Oracle database is running in ARCHIVELOG mode. Archived log files are accessible and a suitable retention period is set for archived log files. For more information, see Managing Archived Redo Log Files.
  • Supplemental logging, including SUPPLEMENTAL_LOG_DATA_PK and SUPPLEMENTAL_LOG_DATA_UI, is enabled for the self-managed Oracle database. For more information, see Supplemental Logging.
  • The destination AnalyticDB for PostgreSQL instance is created. For more information, see Create an AnalyticDB for PostgreSQL instance.

Limits

Note By default, DTS disables FOREIGN KEY constraints for the destination database in a data synchronization task. Therefore, the cascade and delete operations of the source database are not synchronized to the destination database.
Category Description
Limits on the source database
  • Requirements for the objects to be synchronized:
    • The tables to be synchronized must have PRIMARY KEY or UNIQUE constraints, and all fields must be unique. Otherwise, the destination database may contain duplicate data records.
    • If the version of your Oracle database is 12c or later, the names of the tables to be synchronized cannot exceed 30 bytes in length.
    • If you select tables as the objects to be synchronized and you want to edit tables (such as renaming tables or columns), up to 1,000 tables can be synchronized in a single data synchronization task. If you run a task to synchronize more than 1,000 tables, a request error occurs. In this case, we recommend that you split the tables, configure multiple tasks to synchronize the tables, or configure a task to synchronize the entire database.
  • If the source database is an Oracle Real Application Cluster (RAC) database connected over Express Connect, you must specify a virtual IP address (VIP) for the database when you configure the data synchronization task.
  • If the self-managed Oracle database is an Oracle RAC database, you can only use a VIP rather than a Single Client Access Name (SCAN) IP address when you configure the data synchronization task. After you specify the VIP, node failover of the Oracle RAC database is not supported.
  • The following requirements must be met:
    • The redo logging and archive logging features must be enabled.
    • If you perform only incremental data synchronization, the redo logs and archive logs of the source database must be stored for more than 24 hours. If you perform both full data and incremental data synchronization, the redo logs and archive logs of the source database must be stored for at least seven days. After full data synchronization is completed, you can set the retention period to more than 24 hours. Otherwise, DTS may fail to obtain the redo logs and archive logs and the task may fail. In exceptional circumstances, data inconsistency or loss may occur. Make sure that you set the retention period of redo logs and archive logs in accordance with the preceding requirements. Otherwise, the Service Level Agreement (SLA) of DTS does not ensure service reliability and performance.

  • If you perform a primary/secondary switchover on the source database when the data synchronization task is running, the task fails.
Other limits
  • DTS supports schema synchronization for the following types of objects: table, index, constraint, function, sequence, and view.
    Warning
    • Oracle and AnalyticDB for PostgreSQL are heterogeneous databases. DTS does not ensure that the schemas of the source and destination databases are consistent after schema synchronization. We recommend that you evaluate the impact of data type conversion on your business. For more information, see Data type mappings for schema synchronization.
    • In this scenario, DTS is incompatible with triggers. We recommend that you delete the triggers of the source database to prevent data inconsistency caused by triggers. For more information, see Configure a data synchronization task for a source database that contains a trigger.
    • For partitioned tables, DTS discards the partition definitions. You must define partitions in the destination database.
  • Before you synchronize data, evaluate the impact of data synchronization on the performance of the source and destination databases. We recommend that you synchronize data during off-peak hours. During full data synchronization, DTS uses read and write resources of the source and destination databases. This may increase the loads of the database servers.
  • During full data synchronization, concurrent INSERT operations cause fragmentation in the tables of the destination database. After full data synchronization is completed, the tablespace of the destination database is larger than that of the source database.
  • We recommend that you do not use gh-ost or pt-online-schema-change to perform DDL operations on objects. Otherwise, data synchronization may fail.
  • DTS calculates synchronization latency based on the timestamp of the latest synchronized data in the destination database and the current timestamp in the source database. If no DML operation is performed on the source database for a long time, the synchronization latency may be inaccurate. If the latency of the synchronization task is too high, you can perform a DML operation on the source database to update the latency.
    Note If you select an entire database as the object to be synchronized, you can create a heartbeat table. The heartbeat table is updated or receives data every second.
  • During data synchronization, we recommend that you use only DTS to write data to the destination database. This prevents data inconsistency between the source and destination databases. For example, if you use tools other than DTS to write data to the destination database, data loss may occur in the destination database when you use Data Management (DMS) to perform online DDL operations.

Billing

Synchronization type Task configuration fee
Schema synchronization and full data synchronization Free of charge.
Incremental data synchronization Charged. For more information, see Pricing.

Supported synchronization topologies

  • One-way one-to-one synchronization
  • One-way one-to-many synchronization
  • One-way many-to-one synchronization
  • One-way cascade synchronization
For more information about synchronization topologies, see Synchronization topologies.

SQL operations that can be synchronized

Operation type SQL statement
DML INSERT, UPDATE, and DELETE
DDL ADD COLUMN

Permissions required for database accounts

Database Required permission References
Self-managed Oracle database DBA CREATE USER and GRANT
AnalyticDB for PostgreSQL instance Write permissions on the destination database The initial account of the destination AnalyticDB for PostgreSQL instance has the required permissions. For more information, see Create a database account.
Note You can also enter an account that has the RDS_SUPERUSER permission. For more information, see Manage users and permissions.
Notice If you need to synchronize data from an Oracle database but the database administrator (DBA) permission cannot be granted to the database account, you can enable archive logging and supplemental logging, and grant fine-grained permissions to the account.
  1. Enable archive logging and supplemental logging.
    Type Procedure
    Archive logging Execute the following statements to enable archive logging:
    shutdown immediate;
    startup mount;
    alter database archivelog;
    alter database open;
    archive log list;
    Supplemental logging Enable supplemental logging at the database or table level:
    Note You can enable database-level supplemental logging to ensure the stability of DTS tasks. You can enable table-level supplemental logging to reduce the disk usage of the source Oracle database.
    • Enable database-level supplemental logging
      1. Enable minimal supplemental logging:
        alter database add supplemental log data;
      2. Enable primary key and unique key supplemental logging at the database level:
        alter database add supplemental log data (primary key,unique index) columns;
    • Enable table-level supplemental logging
      1. Enable minimal supplemental logging:
        alter database add supplemental log data;
      2. Enable table-level supplemental logging by using one of the following methods:
        • Enable primary key supplemental logging at the table level:
          alter table table_name add supplemental log data (primary key) columns;
        • Enable table-level supplemental logging for all columns:
          alter table tb_name add supplemental log data (all) columns ;
  2. Grant fine-grained permissions to an Oracle database account
    # Create a database account, for example, rdsdt_dtsacct, and grant permissions to the account.
    create user rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct;
    grant create session to rdsdt_dtsacct;
    grant connect to rdsdt_dtsacct;
    grant resource to rdsdt_dtsacct;
    grant execute on sys.dbms_logmnr to rdsdt_dtsacct;
    grant select on V_$LOGMNR_LOGS to rdsdt_dtsacct;
    grant select on  all_objects to rdsdt_dtsacct;
    grant select on  all_tab_cols to rdsdt_dtsacct;
    grant select on  dba_registry to rdsdt_dtsacct;
    grant select any table to rdsdt_dtsacct;
    grant select any transaction to rdsdt_dtsacct;
    -- v$log privileges
    grant select on v_$log to rdsdt_dtsacct;
    -- v$logfile privileges
    grant select on v_$logfile to rdsdt_dtsacct;
    -- v$archived_log privileges
    grant select on v_$archived_log to rdsdt_dtsacct;
    -- v$parameter privileges
    grant select on v_$parameter to rdsdt_dtsacct;
    -- v$database privileges
    grant select on v_$database to rdsdt_dtsacct;
    -- v$active_instances privileges
    grant select on v_$active_instances to rdsdt_dtsacct;
    -- v$instance privileges
    grant select on v_$instance to rdsdt_dtsacct;
    -- v$logmnr_contents privileges
    grant select on v_$logmnr_contents to rdsdt_dtsacct;
    -- system tables
    grant select on sys.USER$ to rdsdt_dtsacct;
    grant select on SYS.OBJ$ to rdsdt_dtsacct;
    grant select on SYS.COL$ to rdsdt_dtsacct;
    grant select on SYS.IND$ to rdsdt_dtsacct;
    grant select on SYS.ICOL$ to rdsdt_dtsacct;
    grant select on SYS.CDEF$ to rdsdt_dtsacct;
    grant select on SYS.CCOL$ to rdsdt_dtsacct;
    grant select on SYS.TABPART$ to rdsdt_dtsacct;
    grant select on SYS.TABSUBPART$ to rdsdt_dtsacct;
    grant select on SYS.TABCOMPART$ to rdsdt_dtsacct;
    grant select on v$database to rdsdt_dtsacct;
    grant select on dba_objects to rdsdt_dtsacct;
    grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct;
    grant select on dba_tab_cols to rdsdt_dtsacct;
    # Switch to the pluggable database (PDB). Create a database account, for example, rdsdt_dtsacct, and grant permissions to the account.
    ALTER SESSION SET container = ORCLPDB1;
    create user rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct;
    grant create  session to rdsdt_dtsacct;
    grant connect  to rdsdt_dtsacct;
    grant resource to rdsdt_dtsacct;
    grant execute on sys.dbms_logmnr to rdsdt_dtsacct;
    grant select on  all_objects to rdsdt_dtsacct;
    grant select on  all_tab_cols to rdsdt_dtsacct;
    grant select on  dba_registry to rdsdt_dtsacct;
    grant select any table to rdsdt_dtsacct;
    grant select any transaction to rdsdt_dtsacct;
    -- v$log privileges
    grant select on v_$log to rdsdt_dtsacct;
    -- v$logfile privileges
    grant select on v_$logfile to rdsdt_dtsacct;
    -- v$archived_log privileges
    grant select on v_$archived_log to rdsdt_dtsacct;
    -- v$parameter privileges
    grant select on v_$parameter to rdsdt_dtsacct;
    -- v$database privileges
    grant select on v_$database to rdsdt_dtsacct;
    -- v$active_instances privileges
    grant select on v_$active_instances to rdsdt_dtsacct;
    -- v$instance privileges
    grant select on v_$instance to rdsdt_dtsacct;
    -- v$logmnr_contents privileges
    grant select on v_$logmnr_contents to rdsdt_dtsacct;
    grant select on sys.USER$ to rdsdt_dtsacct;
    grant select on SYS.OBJ$ to rdsdt_dtsacct;
    grant select on SYS.COL$ to rdsdt_dtsacct;
    grant select on SYS.IND$ to rdsdt_dtsacct;
    grant select on SYS.ICOL$ to rdsdt_dtsacct;
    grant select on SYS.CDEF$ to rdsdt_dtsacct;
    grant select on SYS.CCOL$ to rdsdt_dtsacct;
    grant select on SYS.TABPART$ to rdsdt_dtsacct;
    grant select on SYS.TABSUBPART$ to rdsdt_dtsacct;
    grant select on SYS.TABCOMPART$ to rdsdt_dtsacct;
    -- V$PDBS privileges
    grant select on V_$PDBS to rdsdt_dtsacct;
    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;
    
    # Switch to the container database (CDB). Create a database account and grant permissions to the account by using one of the following methods:
    ALTER SESSION SET container = CDB$ROOT;
    Method 1: Create a global account starting with C##, for example, C##rdsdt_dtsacct, and grant permissions to the account. If you use this method, you must submit a ticket and contact the DTS team to modify some parameters. The link to submit a ticket is provided in the note.
    create user C##rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct;
    grant create session to C##rdsdt_dtsacct;
    grant connect to C##rdsdt_dtsacct;
    grant resource to C##rdsdt_dtsacct;
    grant select on v_$logmnr_contents to rdsdt_dtsacct;
    grant LOGMINING to C##rdsdt_dtsacct;
    grant EXECUTE_CATALOG_ROLE to C##rdsdt_dtsacct;
    grant execute on sys.dbms_logmnr to C##rdsdt_dtsacct;
    grant select on v$database to rdsdt_dtsacct;
    grant select on dba_objects to rdsdt_dtsacct;
    grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct;
    grant select on dba_tab_cols to rdsdt_dtsacct;
    Method 2: Create a database account, for example, rdsdt_dtsacct, and grant permissions to the account. If you use this method, you must modify the default parameters of the Oracle database.
    alter session set "_ORACLE_SCRIPT"=true;
    create user rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct;
    grant create session to rdsdt_dtsacct;
    grant connect to rdsdt_dtsacct;
    grant select on v_$logmnr_contents to rdsdt_dtsacct;
    grant LOGMINING TO rdsdt_dtsacct;
    grant EXECUTE_CATALOG_ROLE to rdsdt_dtsacct;
    grant execute on sys.dbms_logmnr to rdsdt_dtsacct;
    grant select on v$database to rdsdt_dtsacct;
    grant select on dba_objects to rdsdt_dtsacct;
    grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct;
    grant select on dba_tab_cols to rdsdt_dtsacct;
    # Create a database account, for example, rdsdt_dtsacct, and grant permissions to the account.
    create user rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct;
    grant create  session to rdsdt_dtsacct;
    grant connect  to rdsdt_dtsacct;
    grant resource to rdsdt_dtsacct;
    grant select on V_$LOGMNR_LOGS to rdsdt_dtsacct;
    grant select on  all_objects to rdsdt_dtsacct;
    grant select on  all_tab_cols to rdsdt_dtsacct;
    grant select on  dba_registry to rdsdt_dtsacct;
    grant select any table to rdsdt_dtsacct;
    grant select any transaction to rdsdt_dtsacct;
    -- v$log privileges
    grant select on v_$log to rdsdt_dtsacct;
    -- v$logfile privileges
    grant select on v_$logfile to rdsdt_dtsacct;
    -- v$archived_log privileges
    grant select on v_$archived_log to rdsdt_dtsacct;
    -- v$parameter privileges
    grant select on v_$parameter to rdsdt_dtsacct;
    -- v$database privileges
    grant select on v_$database to rdsdt_dtsacct;
    -- v$active_instances privileges
    grant select on v_$active_instances to rdsdt_dtsacct;
    -- v$instance privileges
    grant select on v_$instance to rdsdt_dtsacct;
    -- v$logmnr_contents privileges
    grant select on v_$logmnr_contents to rdsdt_dtsacct;
    grant select on sys.USER$ to rdsdt_dtsacct;
    grant select on SYS.OBJ$ to rdsdt_dtsacct;
    grant select on SYS.COL$ to rdsdt_dtsacct;
    grant select on SYS.IND$ to rdsdt_dtsacct;
    grant select on SYS.ICOL$ to rdsdt_dtsacct;
    grant select on SYS.CDEF$ to rdsdt_dtsacct;
    grant select on SYS.CCOL$ to rdsdt_dtsacct;
    grant select on SYS.TABPART$ to rdsdt_dtsacct;
    grant select on SYS.TABSUBPART$ to rdsdt_dtsacct;
    grant select on SYS.TABCOMPART$ to rdsdt_dtsacct;
    grant LOGMINING TO rdsdt_dtsacct;
    grant EXECUTE_CATALOG_ROLE to rdsdt_dtsacct;
    grant execute on sys.dbms_logmnr to rdsdt_dtsacct;
    grant select on v$database to rdsdt_dtsacct;
    grant select on dba_objects to rdsdt_dtsacct;
    grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct;
    grant select on dba_tab_cols to rdsdt_dtsacct;
    Note To create a global account starting with C## for a multitenant CDB$ROOT in Oracle 12c to 19c, you must submit a ticket and contact the DTS team to modify some parameters.

Procedure

  1. Go to the Data Synchronization page of the new DTS console.
    Note You can also log on to the Data Management console. In the top navigation bar, click DTS. Then, in the left-side navigation pane, choose DTS (DTS) > Data Synchronization.
  2. In the upper-left corner of the page, select the region where the data synchronization instance resides.
    Region
  3. Click Create Task. On the page that appears, configure the source and destination databases.
    Section Parameter Description
    N/A Task Name

    The task name that DTS automatically generates. We recommend that you specify a descriptive name that makes it easy to identify the task. You do not need to use a unique task name.

    Source Database Database Type Select Oracle.
    Access Method The access method of the source database. In this example, Self-managed Database on ECS is selected.
    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 The region where the self-managed Oracle database resides.
    ECS Instance ID The ID of the Elastic Compute Service (ECS) instance that hosts the self-managed Oracle database.
    Port number The service port number of the self-managed Oracle database. Default port value: 1521.
    Oracle Type
    • If you select Non-RAC Instance, you must specify the SID parameter.
    • If you select RAC or PDB Instance, you must specify the Service Name parameter.
      Notice RAC instances are not supported.
    In this example, Non-RAC Instance is selected.
    Database Account The account of the self-managed Oracle database. For information about the permissions that are required for the account, see Permissions required for database accounts.
    Database Password

    The password of the database account.

    Destination Database Database Type Select AnalyticDB for PostgreSQL.
    Access Method Select Cloud Instance.
    Instance Region The region where the destination AnalyticDB for PostgreSQL instance resides.
    Instance ID The ID of the destination AnalyticDB for PostgreSQL cluster.
    Database Name The name of the destination database in the AnalyticDB for PostgreSQL instance.
    Database Account 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

    The password of the database account.

  4. In the lower part of the page, click Test Connectivity and Proceed.
    Note
    • You do not need to modify the security settings for ApsaraDB instances (such as ApsaraDB RDS for MySQL and ApsaraDB for MongoDB) and ECS-hosted databases. DTS automatically adds the CIDR blocks of DTS servers to the whitelists of ApsaraDB instances or the security group rules of ECS instances. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
    • After data synchronization is complete, we recommend that you remove the CIDR blocks of DTS servers from the whitelists or security groups.
  5. Select the objects to migrate.
    • Basic SettingsBasic Settings (Select SQL Operations)
      Parameter Description
      Task Stages

      Incremental Data Synchronization is selected by default. You must also select Schema Synchronization and Full Data Synchronization. After the precheck is complete, DTS synchronizes the historical data of selected objects from the source instance to the destination cluster. The historical data is the basis for subsequent incremental synchronization.

      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 the precheck and the data synchronization 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, and a data record has the same primary key as an existing data record in the destination database:
          • During full data synchronization, DTS does not synchronize the data record to the destination database. The existing data record in the destination database is retained.
          • During incremental data synchronization, DTS synchronizes the data record to the destination database. The existing data record in the destination database is overwritten.
        • If the source and destination databases have different schemas, initial data synchronization may fail. In this case, only part of the columns are synchronized, or the data synchronization task fails.
      Merge Tables
      • Yes: In online transaction processing (OLTP) scenarios, sharding is implemented to speed up the response to business tables. In online analytical processing (OLAP) scenarios, you can store a large amount of data in a single table. It makes your SQL queries more efficient. This way, you can merge multiple source tables that have an identical schema into a single destination table. This feature allows you to synchronize data from multiple tables in the source database to a single table in the destination database.
        Note
        • After you select multiple tables from the source database, you must change the names of these tables to the name of the destination table by using the object name mapping feature. For more information about how to use this feature, see Map object names.
        • DTS adds a column named __dts_data_source to the destination table. This column is used to record the data source. The data type of this column is TEXT. The values of this column are in the following format: data synchronization instance ID:source database name:source schema name:source table name. This allows DTS to identify each source table. Example: dts********:dtstestdata:testschema:customer1.
        • If you set this parameter to Yes, all the selected source tables in the task are merged into a destination table. If you want to merge only part of the source tables, you must create a separate data synchronization task for these tables.
        Warning We recommend that you do not perform DDL operations to change the schemas of source databases or tables. Otherwise, data inconsistency may occur or the migration task fails.
      • No: the default value.
      DDL and DML Operations to Be Synchronized The DDL and DML operations to synchronize. For more information, see SQL operations that can be synchronized.
      Note To select the SQL operations performed on a specific database or table, perform the following steps: In the Selected Objects section, right-click an object. In the dialog box that appears, select the SQL operations that you want to synchronize.
      Select Objects

      Select one or more objects from the Source Objects section and click the Rightwards arrow icon to add the objects to the Selected Objects section.

      Note You can select columns, tables, or databases as objects to synchronize. If you select tables or columns as the objects to synchronize, DTS does not synchronize other objects such as views, triggers, and stored procedures to the destination database.
      Rename Databases and Tables
      • To rename an object in 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 in the destination instance, click Batch Edit in the upper-right corner of the Selected Objects section. For more information, see Map multiple object names at a time.
      Filter data

      You can specify WHERE conditions to filter data. For more information, see Use SQL conditions to filter data.

      Select the SQL operations to be synchronized In the Selected Objects section, right-click an object. In the dialog box that appears, select the DML and DDL operations to synchronize. For more information, see SQL operations that can be synchronized.
    • Advanced SettingsAdvanced Settings
      Parameter Description
      Set Alerts
      Specifies whether to set alerts for the data synchronization task. If you select yes, DTS sends notifications to contacts if the task fails or the synchronization latency exceeds the upper limit.
      • No: does not set alerts.
      • Yes: sets alerts. In this case, you must also set the alert threshold and alert contacts.
      Retry Time for Failed Connection
      Specifies the retry time range for failed connections. Valid values: 10 to 1440. Unit: minutes. Default value: 120. 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 less value that is specified for the instance 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.
      Enclose Object Names in Quotation Marks
      Specifies whether you need to enclose object names in quotation marks. If you select Yes and the following conditions are met, DTS encloses object names in single quotation marks (') or double quotation marks (") during schema synchronization and incremental data synchronization:
      • The business environment of the source database is case-sensitive and the database name contains both uppercase and lowercase letters.
      • A source table name does not start with a letter and contains characters other than letters, digits, and special characters.
        Note A source table name can contain only the following special characters: underscores (_), number signs (#), and dollar signs ($).
      • The names of the schemas, tables, or columns that you want to synchronize are keywords, reserved keywords, or invalid characters in the destination database.
      Note If you select Yes, after the data synchronization task is completed, you must specify the object name in quotation marks to query the object.
  6. In the lower part of the page, click Next: Configure Database and Table Fields. On the page that appears, set the primary key column and distribution column of the tables that you want to synchronize to the destination AnalyticDB for PostgreSQL instance.
    AnalyticDB for PostgreSQL: Specify the primary key columns and distribution keys
  7. Click Next: Save Task Settings and Precheck in the lower part of the page.
    Note
    • Before you can start the data synchronization task, DTS performs a precheck. You can start the data synchronization task only after the task passes the precheck.
    • If the task fails to pass the precheck, you can click the Info icon icon next to each failed item to view details.
      • After you troubleshoot the issues based on the causes, you can 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 billing method and specifications for the data synchronization instance. The following table describes related parameters.
    Section Parameter Description
    Parameters Billing method
    • Subscription: You pay for your subscription when you create an instance. The subscription billing method is more cost-effective than the pay-as-you-go billing method for long-term use.
    • Pay-as-you-go: A pay-as-you-go instance is billed on an hourly basis. For short-term use, we recommend that you select the pay-as-you-go billing method. If you no longer need a pay-as-you-go instance, you can release the instance to reduce costs.
    Instance Class DTS provides several instance classes that have different performance in synchronization speed. You can select an instance class based on your business scenario. For more information, see Specifications of data synchronization instances.
    Subscription Duration If you select the subscription billing method, set the subscription duration and the number of instances that you want to create. The subscription duration can be one to nine months or one to three years.
    Note This parameter is available only if you select the subscription billing method.
  10. Read and select Data Transmission Service (Pay-as-you-go) Service Terms.
  11. Click Buy and Start to start the data synchronization task. You can view the progress of the task in the task list.