Parameter | Description |
Migration Types | Only Schema Migration and Incremental Data Migration are supported for data migration from a PolarDB-X 2.0 instance to a DataHub project. You can select a migration type based on your business requirements. Note If Schema Migration is selected, the foreign keys in the source database are also migrated to the destination database. If Incremental Data Migration is not selected, we recommend that you do not write data to the source instance during data migration. This ensures data consistency between the source and destination instances.
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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 tables that have identical table names, the precheck is passed. Otherwise, an error is returned during the 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 tables that have 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 the following potential risks: If the source and destination databases have the same schemas, DTS does not migrate data records that have the same primary key values 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. Proceed with caution.
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Naming Rules of Additional Columns | After DTS migrates data to DataHub, DTS adds additional columns to the destination table. If the names of additional columns are the same as the names of existing columns in the destination table, data migration fails. You can select New Rule or Previous Rule based on your business requirements. Warning Before you specify this parameter, check whether additional columns have the same names as the existing columns in the destination table. For more information about the naming rules for additional columns, see Naming rules for additional columns. |
Capitalization of Object Names in Destination Instance | 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 ensure 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. |
Source Objects | Select one or more objects from the Source Objects section. Click the icon and add the objects to the Selected Objects section. Note You can select columns, tables, or databases as the objects to be migrated. If you select tables as the objects to be migrated, DTS does not migrate other objects such as views, triggers, or stored procedures to the destination database. If you select a database as the object to be migrated, DTS migrates data based on the following default rules: If the table to be migrated in the source database has a primary key, such as a single-column primary key or a composite primary key, the primary key columns are specified as the distribution keys. If the table to be migrated in the source database does not have a primary key, an auto-increment primary key column is automatically generated in the destination table. This may cause data inconsistency between the source and destination databases.
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Selected Objects | - 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 Batch Edit 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. To specify WHERE conditions to filter data, right-click an object in the Selected Objects section. In the dialog box that appears, specify the conditions. For more information, see Use SQL conditions to filter data. To select the SQL operations performed on a specific database or table, right-click an object in the Selected Objects section. In the dialog box that appears, select the SQL operations that you want to migrate. For more information, see the SQL operations that can be incrementally migrated section of this topic.
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