Overview

This topic describes how to use DTS tasks to perform the PreCheck.

 

Description

DTS checks the PreCheck constraints to ensure successful data migration. This item checks whether the parent and child tables of the foreign key dependencies of the objects to be migrated have been migrated, preventing the integrity of foreign key constraints from being damaged. If this item fails to pass the precheck, the parent tables that the child tables to be migrated depend on are not selected as objects to be migrated. You can choose any of the following methods to fix this issue based on your business needs.

 

Method 1: Add the parent table to the object to be migrated.

Follow these steps to select parent tables of the tables that fail the precheck as objects to be migrated.

  1. Login DTS console in the left-side navigation pane, find the target migration task, and then click modify task configurations.
  2. In the source and destination databases page, click the authorize the whitelist and go to the next step..
  3. Select the parent tables of the child tables that fail to pass the PreCheck and click pre-Check and start.

 

Method 2: Remove the corresponding child tables from the migration object.

  1. Login DTS console in the left-side navigation pane, find the target migration task, and then click modify task configurations.
  2. In the source and destination databases page, click the authorize the whitelist and go to the next step..
  3. Select the child table that fails the PreCheck, remove the table, and click pre-Check and start.

 

Method 3: delete related foreign key dependencies

Follow these steps to delete foreign key dependencies from the source tables that fail to pass the precheck.

  1. Log on to the source database.
  2. Run a command to delete foreign key dependencies from the tables that fail the precheck.
    Note: You can also perform operations in the DMS console. For more information, see manage foreign keys.
  3. Perform another precheck.

 

Application scope

  • Data Transmission Service (DTS)