Create an Oracle Data Subscription channel

Usage notes

• Online DDL changes by tools such as gh-ost or pt-online-schema-change are not tracked. The client may fail to write consumed data to the destination table due to schema mismatches.
• If the source database is used in another task such as data migration, data outside your subscription scope may be tracked. Filter unwanted data in your client application.

Preparations

Log on to the source Oracle database and create a database account with DBA privileges for Data Subscription.

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 Enable minimal supplemental logging: alter database add supplemental log data; 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 Enable minimal supplemental logging: alter database add supplemental log data; 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.

   Oracle Versions 9i to 11g

   # 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;

Procedure

1. Purchase a Data Subscription channel. Purchase process.

   Note

   On the buy page, set Subscription Instance Type to Oracle and select the source instance region.

2. Log on to the DTS console.

3. In the navigation pane on the left, click Change Tracking.

4. At the top of the Data Subscription page, select the region of the subscription channel.

5. Find the purchased Data Subscription channel and click Configure Subscription Channel.

6. Configure the source database and network type.

   

   Category	Parameter	Description
   N/A	Subscription name	DTS generates a name automatically. Use a descriptive name for easier identification. Uniqueness is not required.
   Source database information	Instance type	Select the source instance type. This example uses User-Created Database with Public IP. Note If your self-managed database is of a different instance type, you may need to complete additional preparations. For more information, see Preparations for data migration.
   	Database type	Auto-filled as Oracle. Cannot be changed.
   	Instance region	The Source Instance Region selected during purchase. Cannot be changed.
   	ECS instance ID	Select the ECS instance that hosts your self-managed Oracle database.
   	Port	The service port of the self-managed Oracle database.
   	SID	The SID of the self-managed Oracle database.
   	Database account	The database account of the self-managed Oracle database. Note Follow the Preparations to create and configure this account.
   	Database password	Enter the password of the database account.
   Consumption network type	N/A	The network type for the Data Subscription channel. Note Select the same network type as the ECS instance where your subscription client is deployed. For example, if the ECS instance is in a VPC, select VPC as the network type and specify the Proprietary Network and vSwitch. Private network connections minimize latency. Classic Network If you set the network type to Classic Network, no other configuration is needed. What is a classic network?. Proprietary Network If you set the network type to Proprietary Network, you must also select a Proprietary Network and a vSwitch. What is a VPC?.

7. Click Authorize Whitelist and Proceed to Next Step.

   DTS adds its server CIDR blocks to the source database configuration. For Alibaba Cloud instances such as ApsaraDB RDS for MySQL or ApsaraDB for MongoDB, CIDR blocks are added to the instance whitelist. For self-managed databases on ECS, DTS adds CIDR blocks to security group rules, but you must also add them to the database whitelist. CIDR blocks of DTS servers.

   Warning Adding public CIDR blocks poses security risks. Use strong passwords, restrict open ports, authenticate internal APIs, review network access regularly, and use private connections through Express Connect, VPN Gateway, or Smart Access Gateway.

8. Configure the data types and subscription objects.

   

   Parameter	Description
   Required data types	Data Update Subscribes to data changes (INSERT, DELETE, and UPDATE operations) for the selected objects. Schema Update Subscribes to schema changes (CREATE, DROP, and ALTER operations) for all objects in the instance. Filter for required data in your client application. Note Selecting an entire database also tracks changes to objects added later. Selecting a specific table tracks only that table. To track new tables, add them to the subscription objects. Modify the objects for change tracking.
   Required objects	In the Required Objects box, select objects to track and click Note You can select objects at the database or table level.

9. In the lower-right corner of the page, click Save and Precheck.

   Note

   • DTS runs a precheck before the subscription task starts. The task starts only after the precheck passes.

   • If the precheck fails, click the icon next to the failed item for details. Fix the issues and rerun the precheck.

10. After Precheck Passed appears in the Precheck dialog box, close the Precheck dialog box.

    The Data Subscription channel enters initialization, which typically takes about one minute. After initialization, create consumer groups and start consuming subscription data.