This topic describes how to migrate data from a self-managed Oracle database to an AnalyticDB for PostgreSQL instance by using Data Transmission Service (DTS).
Prerequisites
The engine version 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 instance.
Billing rules
Migration type | Task configuration fee | Internet traffic fee |
Schema migration and full data migration | Free of charge. | Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Billing overview. |
Incremental data migration | Charged. For more information, see Billing overview. |
Usage notes
During full data migration, DTS uses read and write resources of the source and destination databases. This may increase the loads of the database servers. Before you migrate data, evaluate the impact of data migration on the performance of the source and destination databases. We recommend that you migrate data during off-peak hours.
If a data migration task fails and stops, DTS automatically resumes the task. Before you switch your workloads to the destination database, stop or release the data migration task. Otherwise, the data from the source database overwrites the data in the destination database after the task is resumed.
If the self-managed Oracle database is deployed in a Real Application Cluster (RAC) architecture and is connected to DTS over an Alibaba Cloud virtual private cloud (VPC), you must connect the Single Client Access Name (SCAN) IP address of the Oracle RAC and the virtual IP address (VIP) of each node to the VPC and configure routes. The settings ensure that your DTS task can run as expected. For more information, see Connect a data center to DTS by using VPN Gateway.
ImportantWhen you configure the source Oracle database in the DTS console, you can specify the SCAN IP address of the Oracle RAC as the database endpoint or IP address.
Migration types
Migration type | Description |
Schema migration | DTS migrates the schemas of the objects from the source database to the destination database. DTS supports schema migration for the following types of objects: table, index, constraint, function, sequence, and view. Warning
|
Full data migration | DTS migrates historical data of the objects from the source database to the destination database. Note During schema migration and full data migration, do not perform DDL operations on the objects to be migrated. Otherwise, the objects may fail to be migrated. |
Incremental data migration | After full data migration is complete, DTS retrieves redo log files from the source Oracle database. Then, DTS migrates incremental data from the source Oracle database to the destination database in real time. DTS can migrate the following SQL operations during incremental data migration:
Incremental data migration ensures the service continuity of self-managed applications during data migration. |
Permissions required for database accounts
Database | Schema migration | Full data migration | Incremental data migration |
Self-managed Oracle database | Permissions of the schema owner | Permissions of the schema owner | Database administrator (DBA) |
AnalyticDB for PostgreSQL | Read and write permissions on the destination database | Read and write permissions on the destination database | Read and write permissions on the destination database |
For more information about how to create a database account and grant permissions to the database account, see the following topics:
Self-managed Oracle database: CREATE USER and GRANT
AnalyticDB for PostgreSQL instance: Create a database account
If you need to migrate incremental data from an Oracle database but the DBA permission cannot be granted to the database account, you can grant fine-grained permissions to the account. The following section describes how to grant specific permissions to an Oracle database account.
Enable logging and grant fine-grained permissions to an Oracle database account
If you need to migrate incremental data from an Oracle database but the DBA permissions cannot be granted to the database account, you can enable archive logging and supplemental logging, and grant fine-grained permissions to the account.
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 based on your business requirements.
NoteYou can enable database-level supplemental logging to ensure the stability of Data Transmission Service (DTS) tasks. You can enable table-level supplemental logging to reduce the disk usage of the source Oracle database.
Enable database-level supplemental logging
Execute the following statement to enable minimal supplemental logging:
alter database add supplemental log data;
Execute the following statement to 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
Execute the following statement to 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;
Force logging
Execute the following statement to enable force logging:
alter database force logging;
Grant fine-grained permissions to an Oracle database account.
Oracle versions 9i to 11g
# Create a database account named 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_catalog_role TO rdsdt_dtsacct;
Oracle versions 12c to 19c that use the multitenant architecture
# Switch to the pluggable database (PDB). Create a database account named 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$database to rdsdt_dtsacct; grant select on dba_objects to rdsdt_dtsacct; grant select on DBA_TAB_COMMENTS to rdsdt_dtsacct; grant select on dba_tab_cols to rdsdt_dtsacct; grant select_catalog_role TO rdsdt_dtsacct; # Switch to the CDB$ROOT, which is the root container of the container database (CDB). Create a database account and grant permissions to the account. ALTER SESSION SET container = CDB$ROOT; # Create a database account named rdsdt_dtsacct and grant permissions to the account. You must modify the default parameters of the Oracle database. alter session set "_ORACLE_SCRIPT"=true; create user rdsdt_dtsacct IDENTIFIED BY rdsdt_dtsacct; grant create session to rdsdt_dtsacct; grant connect to rdsdt_dtsacct; grant select on v_$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;
Oracle versions 12c to 19c that use a non-multitenant architecture
# Create a database account named 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_$LOGMNR_LOGS to rdsdt_dtsacct; grant select on all_objects to rdsdt_dtsacct; grant select on all_tab_cols to rdsdt_dtsacct; grant select on dba_registry to rdsdt_dtsacct; grant select any table to rdsdt_dtsacct; grant select any transaction to rdsdt_dtsacct; grant select on v$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; -- 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_catalog_role TO rdsdt_dtsacct;
Procedure
Log on to the DTS console.
NoteIf you are redirected to the Data Management (DMS) console, you can click the icon in the to go to the previous version of the DTS console.
In the left-side navigation pane, click Data Migration.
In the upper part of the Migration Tasks page, select the region where the destination instance resides.
In the upper-right corner of the page, click Create Migration Task.
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. You do not need to specify a unique task name.
Source Database
Instance Type
The access method of the source database. In this example, User-Created Database in ECS Instance is selected.
NoteIf you select a different instance type, you must set up the environment that is required for the self-managed database. For more information, see Preparation overview.
Instance Region
The region where the Elastic Compute Service (ECS) instance resides. The self-managed Oracle database is hosted on the ECS instance.
ECS Instance ID
The ID of the ECS instance on which the self-managed Oracle database is hosted.
Database Type
The type of the source database. Select Oracle.
Port Number
The service port number of the self-managed Oracle database. Default value: 1521.
Instance Type
The architecture type of the self-managed Oracle database. 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.
In this example, Non-RAC Instance is selected.
SID
The system ID (SID) of the self-managed Oracle database.
Database Account
The account of the self-managed Oracle database. For information about the permissions that are required for the account, see the "Permissions required for database accounts" section of this topic.
Database Password
The password of the database account.
NoteAfter you specify the information about the source database, you can click Test Connectivity next to Database Password to check whether the information is valid. If the information is valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Then, modify the information based on the check results.
Destination Database
Instance Type
The type of the destination database. Select AnalyticDB for PostgreSQL.
Instance Region
The region where the destination AnalyticDB for PostgreSQL instance resides.
Instance ID
The ID of the destination AnalyticDB for PostgreSQL instance.
Database Name
The name of the destination database.
Database Account
The database account of the destination AnalyticDB for PostgreSQL instance. For information about the permissions that are required for the account, see the "Permissions required for database accounts" section of this topic.
Database Password
The password of the database account.
In the lower-right corner of the page, click Set Whitelist and Next.
WarningIf the CIDR blocks of DTS servers are automatically or manually added to the whitelist of the database or instance, or to the 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 username 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.
Select the migration types, the operation types, and the objects to be migrated.
Setting
Description
Select the migration types
To perform only full data migration, select Schema Migration and Full Data Migration.
To ensure service continuity during data migration, select Schema Migration, Full Data Migration, and Incremental Data Migration.
NoteIf Incremental Data Migration is not selected, we recommend that you do not write data to the source database during full data migration. This ensures data consistency between the source and destination databases.
Select the operation types
Select the types of operations that you want to migrate during incremental data migration. By default, all operation types are selected.
Select the objects to be migrated
Select one or more objects from the Available section and click the icon to add the objects to the Selected section.
NoteYou can select columns, tables, or schemas as the objects to be migrated.
By default, after an object is migrated to the destination database, the name of the object remains unchanged. You can use the object name mapping feature to rename the objects that are migrated to the destination database. For more information, see Object name mapping.
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.
Specify whether to rename objects
You can use the object name mapping feature to rename the objects that are migrated to the destination instance. For more information, see Object name mapping.
Specify the retry time range for a failed connection to the source or destination database
By default, if DTS fails to connect to the source or destination database, DTS retries within the following 12 hours. You can specify the retry time range based on your business requirements. If DTS is reconnected to the source and destination databases within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails.
NoteWithin the retry time range in which DTS attempts to reconnect to the source and destination databases, you are charged for the DTS instance. We recommend that you specify the retry time range based on your business requirements. You can also release the DTS instance at the earliest opportunity after the source and destination instances are released.
Enclose object names in quotation marks
Specifies whether 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 migration and incremental data migration.
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.
NoteA 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 of the destination database, reserved keywords, or invalid characters.
Specify the primary key columns and distribution keys of the tables that you want to migrate to the AnalyticDB for PostgreSQL instance.
NoteFor more information about primary key columns and distribution keys, see Define constraints and Define table distribution.
If DTS identifies tables without primary keys, the option Set Primary Keys and Distribution Keys of All Tables Without Primary Keys to ROWID is displayed on the preceding page. If you select this option, DTS adds the ROWID field as the primary key and distribution key to the destination tables.
In the lower-right corner of the page, click Precheck.
NoteBefore 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.
After the task passes the precheck, click Next.
In the Confirm Settings dialog box, specify the Channel Specification parameter and select Data Transmission Service (Pay-As-You-Go) Service Terms.
Click Buy and Start to start the data migration task.
Schema migration and full data migration
We recommend that you do not manually stop the task during full data migration. Otherwise, the data migrated to the destination database may be incomplete. You can wait until the data migration task automatically stops.
Schema migration, full data migration, and incremental data migration
An incremental data migration task does not automatically stop. You must manually stop the task.
ImportantWe recommend that you select an appropriate time to manually stop the data migration task. For example, you can stop the task during off-peak hours or before you switch your workloads to the destination cluster.
Wait until Incremental Data Migration and The migration task is not delayed appear in the progress bar of the migration task. Then, stop writing data to the source database for a few minutes. The latency of incremental data migration may be displayed in the progress bar.
Wait until the status of incremental data migration changes to The migration task is not delayed again. Then, manually stop the migration task.