Migrate data between user-created Oracle databases

Precautions

• DTS uses read and write resources of the source and destination databases during full data migration. This may increase the database load. 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 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 usage of the source and destination databases is less than 30%.
• The source database must have PRIMARY KEY or UNIQUE constraints and all fields must be unique. Otherwise, duplicate data may exist in the destination database.
• DTS automatically resumes a failed data migration task. Before you switch your workloads to the destination database, stop or release the data migration task. Otherwise, the data in the source database will overwrite the data in the destination database after the task is resumed.

Billing

Migration types

SQL operations that can be synchronized during incremental data migration

• INSERT, UPDATE, and DELETE operations
• CREATE TABLE operations
  Note The CREATE TABLE operations to create partition tables or tables that contain functions cannot be synchronized.
• ALTER TABLE, DROP TABLE, RENAME TABLE, CREATE INDEX, and ADD INDEX operations

Permissions required for database accounts

For more information about how to create and authorize an Oracle database account, see CREATE USER and GRANT.

create session;
connect;
resource;
execute on sys.dbms_logmnr;
select on v_$logmnr_contents;
select on v_$log;
select on v_$logfile;
select on v_$archived_log;
select on v_$logmnr_logs;
select on v_$parameter;
select on v_$database;
select on all_objects;
select on all_tab_cols;
select on dba_registry;
select any table;
select any transaction;
select on v$active_instances;
select on v$instance;
select on sys.USER$;
select on SYS.OBJ$;
select on SYS.COL$;
select on SYS.IND$;
select on SYS.ICOL$;
select on SYS.CDEF$;
select on SYS.CCOL$;
select on SYS.TABPART$;
select on SYS.TABSUBPART$;
select on SYS.TABCOMPART$;
select on gv_$listener_network;

#Grant permissions on the pluggable database (PDB) and container database (CDB).
#Grant permissions on the PDB:
create   session;
connect;
resource;
select on  all_objects;
select on  all_tab_cols;
select on  dba_registry;
select any table;
select any transaction;
select on v_$log;
select on v_$logfile;
select on v_$archived_log;
select on v_$parameter;
select on v_$database;
select on v_$active_instances;
select on v_$instance;
select on V_$PDBS;
select on sys.USER$;
select on SYS.OBJ$;
select on SYS.COL$;
select on SYS.IND$;
select on SYS.ICOL$;
select on SYS.CDEF$;
select on SYS.CCOL$;
select on SYS.TABPART$;
select on SYS.TABSUBPART$;
select on SYS.TABCOMPART$;

#Grant permissions on the CDB:
create   session;
LOGMINING;
select on v_$logmnr_contents;

#The following sample statements show you how to grant permissions to a database account named dtstest.
create user dtstest IDENTIFIED BY rdsdt_dtsacct;
grant create session to dtstest;
grant connect to dtstest;
grant resource to dtstest;
grant execute on sys.dbms_logmnr to dtstest;
grant select on v_$logmnr_contents to dtstest;
grant select on v_$log to dtstest;
grant select on v_$logfile to dtstest;
grant select on v_$archived_log to dtstest;
grant select on v_$logmnr_logs to dtstest;
grant select on v_$parameter to dtstest;
grant select on v_$database to dtstest;
grant select on all_objects to dtstest;
grant select on all_tab_cols to dtstest;
grant select on dba_registry to dtstest;
grant select any table to dtstest;
grant select any transaction to dtstest;
grant select on v$active_instances to dtstest;
grant select on v$instance to dtstest;
grant select on sys.USER$ to dtstest;
grant select on SYS.OBJ$ to dtstest;
grant select on SYS.COL$ to dtstest;
grant select on SYS.IND$ to dtstest;
grant select on SYS.ICOL$ to dtstest;
grant select on SYS.CDEF$ to dtstest;
grant select on SYS.CCOL$ to dtstest;
grant select on SYS.TABPART$ to dtstest;
grant select on SYS.TABSUBPART$ to dtstest;
grant select on SYS.TABCOMPART$ to dtstest;
grant select on gv_$listener_network to dtstest;

#The following sample statements show you how to grant permissions on the pluggable database (PDB) and container database (CDB) to a database account named dtstest.
#Grant permissions on the PDB:
create user dtstest IDENTIFIED BY rdsdt_dtsacct;
grant create  session to dtstest;
grant connect  to dtstest;
grant resource to dtstest;
grant select on  all_objects to dtstest;
grant select on  all_tab_cols to dtstest;
grant select on  dba_registry to dtstest;
grant select any table to dtstest;
grant select any transaction to dtstest;
-- v$log privileges
grant select on v_$log to dtstest;
-- v$logfile privileges
grant select on v_$logfile to dtstest;
-- v$archived_log privileges
grant select on v_$archived_log to dtstest;
-- v$parameter privileges
grant select on v_$parameter to dtstest;
-- v$database privileges
grant select on v_$database to dtstest;
-- v$active_instances privileges
grant select on v_$active_instances to dtstest;
-- v$instance privileges
grant select on v_$instance to dtstest;
-- V$PDBS privileges
grant select on V_$PDBS to dtstest;
grant select on sys.USER$ to dtstest;
grant select on SYS.OBJ$ to dtstest;
grant select on SYS.COL$ to dtstest;
grant select on SYS.IND$ to dtstest;
grant select on SYS.ICOL$ to dtstest;
grant select on SYS.CDEF$ to dtstest;
grant select on SYS.CCOL$ to dtstest;
grant select on SYS.TABPART$ to dtstest;
grant select on SYS.TABSUBPART$ to dtstest;
grant select on SYS.TABCOMPART$ to dtstest;

#Grant permissions on the CDB:
create user dtstest IDENTIFIED BY rdsdt_dtsacct;
grant create   session to dtstest;
grant LOGMINING TO dtstest;
-- v$logmnr_contents privileges
grant select on v_$logmnr_contents to dtstest;

Procedure

The procedure in this topic uses a user-created database hosted on ECS as an example. You can also follow the procedure to configure data migration tasks for other types of user-created Oracle databases.

1. Log on to the DTS console.
2. In the left-side navigation pane, click Data Migration.
3. At the top of Migration Tasks the 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 for the data migration task.
   

   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 in ECS Instance. Note If you select other instance types, you must prepare the environments that are required for the source database. For more information, see Preparation overview.
   	Instance Region	Select the region of the ECS instance on which the source Oracle database is deployed.
   	ECS Instance ID	Select the ID of the ECS instance on which the source Oracle database is deployed.
   	Database Type	Select Oracle.
   	Port Number	Enter the service port number of the source Oracle database.
   	Instance Type	Non-RAC Instance: If you select this option, you must specify the SID. RAC Instance: If you select this option, you must specify the Service Name.
   	Database Account	Enter the account of the source Oracle database. For more information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password for the source 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 User-Created Database in ECS Instance.
   	Instance Region	Select the region of the ECS instance on which the destination Oracle database is deployed.
   	ECS Instance ID	Select the ID of the ECS instance on which the destination Oracle database is deployed.
   	Database Type	Select Oracle.
   	Port Number	Enter the service port number of the destination Oracle database.
   	Instance Type	Non-RAC Instance: If you select this option, you must specify the SID. RAC Instance: If you select this option, you must specify the Service Name.
   	Database Account	Enter the account of the destination Oracle database. For more information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password for the destination database account. Note After you specify the destination database parameters, click Test Connectivity next to Database Password to verify whether the 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.
7. Select the migration types and objects to be migrated.
   

   Parameter	Description
   Migration Types	To perform only full data migration, select Schema Migration and Full Data Migration. To migrate data with minimal downtime, select Schema Migration, Full Data Migration, and Incremental Data Migration. Note If Incremental Data Migration is not selected, do not write data into the source Oracle database during full data migration. This ensures data consistency between the source and destination databases. For more information about migration types, see Migration types.
   Objects	Select 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. After an object is migrated to the destination Oracle database, the name of the object remains the same as that in the source Oracle database. You can change the names of the objects that are migrated to the destination Oracle database by using the object name mapping feature. For more information about how to use this feature, see Object name mapping. If you use the object name mapping feature on an object, other objects that are dependent on the object may fail to be migrated.

8. Click Precheck on the lower right of the page.
   Note

   • A precheck is performed for a data migration task. A data migration task can be started only if it passes the precheck.
   • If the precheck fails, click corresponding to each failed item to view the details. Fix the problems as instructed and run the precheck again.
9. After the precheck is passed, click Next.
10. On the Confirm Settings dialog box that appears, specify Channel Specification and select the Data Transmission Service (Pay-As-You-Go) Service Terms.
11. Click Buy and Start to start the data migration task.
    • Schema migration and full data migration

      Do not manually stop a migration task. Otherwise, data migrated to the destination database will be incomplete. Wait until the data migration task stops when it is complete.

    • Schema migration, full data migration, and incremental data migration

      An incremental data migration task does not automatically end. You must manually end the migration task.

      Note Select an appropriate time point to manually end the migration task. For example, you can end the migration task during off-peak hours or before you switch your workloads to the destination cluster.
      1. When the task progress bar switches to Incremental Data Migration and the message The migration task is not delayed appears, stop writing new data to the source database for a few minutes. Then, the progress bar will show the latency of the incremental data migration.
      2. When the status of incremental data migration changes to The migration task is not delayed, manually stop the migration task.