View data verification details - Data Transmission Service

This topic describes how to view the details of a data verification task in Data Transmission Service (DTS).

Prerequisites

A data verification task is created and configured. For more information, see Configure data verification.

Usage notes

By default, the information about data inconsistency that is detected by full data verification tasks and incremental data verification tasks are retained for 30 days. We recommend that you view the information and handle the data inconsistency issues in a timely manner.

View verification tasks on the Data Verification page

Go to the Data Synchronization Tasks or Data Migration Tasks page.
1. Log on to the Data Management (DMS) console.
2. In the top navigation bar, click DTS.
3. In the left-side navigation pane, choose DTS (DTS) > Data Verification.
On the top of the Verification Task list, select the region of the instance you want to manage.
Note
If you use the new DTS console, you must select the region from the region drop-down list to the right of Workbench in the top navigation bar.
Click the instance ID to go to the instance details page.
Optional. In the left-side pane, click Task Management.
In the Progress section, click the Full Data Verification, Incremental Data Verification, or Schema Verification module to view the details of data verification.
- Basic information
  On the Basic Information tab, you can view the information about data verification, such as the start time, verification time rules, status, actions, and error messages. The actual information displayed in the console prevails.
  After data verification starts, you can restart, pause, stop, or Delete based on your business requirements. For more information, see What to do next.
  Important
  On the Basic Information tab, the Status parameter indicates the state of data verification. You can view the results of data verification on the Check Details tab.
- Check Details
  On the Check Details tab, you can filter and view the results of data verification, such as the source and destination database names, table names in the source and destination databases, the state of data verification, and the point in time of data verification.
  Note
  For full data verification and schema verification, we recommend that you view the details of data verification when the value of the Status parameter is Completed. For incremental data verification, we recommend that you view the details of data verification when the Current Offset parameter indicates a point in time later than the point in time when incremental data is changed.
  On the Check Details tab, the results of data verification are displayed in descending order based on the values in the Number of Inconsistent Records column.
  During incremental data verification, the changes of the same data record within a certain period of time are merged. Therefore, the number of data records displayed in the results of incremental data verification may be less than that of incremental data changes.
  You can download revised SQL statements only from the results of full data verification. If full data verification was started before 14:04:52 on November 20, 2023, you must restart full data verification before you can download revised SQL statements.
  The value in the Total Number of Records column specifies the estimated number of records to be verified. The value in the Number of records completed by verification column specifies the number of records that are verified. Therefore, the value in the Number of records completed by verification column may be larger than that in the Total Number of Records column.
  - If the value in the Number of Inconsistent Records column is 0, data is consistent between the source and destination objects. In this case, you do not need to view or download the data verification report because the report does not contain data.
  - If the value in the Number of Inconsistent Records column is not 0, data or schema inconsistency is detected between the source and destination objects. In the Actions column, you can click View Report, Download Report, or Download Revised SQL Statements based on your business requirements. Then, you can manually modify the inconsistent data or schemas based on the data verification report or revised SQL statements.
    Important
    Execute the DELETE statement in the revised SQL statements with caution.

View the details of data verification configured for a data synchronization or migration task in DTS

Go to the Data Synchronization Tasks or Data Migration Tasks page.
1. Log on to the Data Management (DMS) console.
2. In the top navigation bar, click DTS.
3. In the left-side navigation pane, choose DTS (DTS) > Data Synchronization or DTS (DTS) > Data Migration.
Note
- If you use the simple mode of the DMS console, move the pointer over the icon in the upper-left corner and choose All functions > DTS > Data Synchronization or All functions > DTS > Data Migration. For more information, see Configure the DMS console based on your business requirements.
- You can also go to the Data Synchronization Tasks or Data Migration Tasks page of the new DTS console.
Select the region in which your data synchronization or migration task resides from the drop-down list to the right of Data Synchronization Tasks or Data Migration Tasks.
Note
If you use the new DTS console, you must select the region from the region drop-down list to the right of Workbench in the top navigation bar.
Click the ID of the data synchronization or migration task to go to the task details page.
Optional. In the left-side pane, click Task Management.
Clear Hide Completed Modules next to Progress.
In the Progress section, click the Full Data Verification, Incremental Data Verification, or Schema Verification module to view the details of data verification.
- Basic information
  On the Basic Information tab, you can view the information about data verification, such as the start time, verification time rules, status, actions, and error messages. The actual information displayed in the console prevails.
  After data verification starts, you can restart, pause, stop, or Delete based on your business requirements. For more information, see What to do next.
  Important
  On the Basic Information tab, the Status parameter indicates the state of data verification. You can view the results of data verification on the Check Details tab.
- Check Details
  On the Check Details tab, you can filter and view the results of data verification, such as the source and destination database names, table names in the source and destination databases, the state of data verification, and the point in time of data verification.
  Note
  For full data verification and schema verification, we recommend that you view the details of data verification when the value of the Status parameter is Completed. For incremental data verification, we recommend that you view the details of data verification when the Current Offset parameter indicates a point in time later than the point in time when incremental data is changed.
  On the Check Details tab, the results of data verification are displayed in descending order based on the values in the Number of Inconsistent Records column.
  During incremental data verification, the changes of the same data record within a certain period of time are merged. Therefore, the number of data records displayed in the results of incremental data verification may be less than that of incremental data changes.
  You can download revised SQL statements only from the results of full data verification. If full data verification was started before 14:04:52 on November 20, 2023, you must restart full data verification before you can download revised SQL statements.
  The value in the Total Number of Records column specifies the estimated number of records to be verified. The value in the Number of records completed by verification column specifies the number of records that are verified. Therefore, the value in the Number of records completed by verification column may be larger than that in the Total Number of Records column.
  - If the value in the Number of Inconsistent Records column is 0, data is consistent between the source and destination objects. In this case, you do not need to view or download the data verification report because the report does not contain data.
  - If the value in the Number of Inconsistent Records column is not 0, data or schema inconsistency is detected between the source and destination objects. In the Actions column, you can click View Report, Download Report, or Download Revised SQL Statements based on your business requirements. Then, you can manually modify the inconsistent data or schemas based on the data verification report or revised SQL statements.
    Important
    Execute the DELETE statement in the revised SQL statements with caution.

What to do next

If you need to verify data consistency between the source and destination objects again after you modify the inconsistent data, you can perform the following operations in the Progress section to manage data verification.

Important

The following operations do not apply to schema verification.
If a button is dimmed, the corresponding operation is not supported in the current state of data verification.

Go to the Task Management page of your DTS task.
Clear Hide Completed Modules next to Progress.
Click the Full Data Verification or Incremental Data Verification module.
Optional. Click the Basic Information tab.
Manage data verification.
- Pause data verification
  Important
  You can pause data verification only after data verification starts.
  After full data verification is paused, the value of the Status parameter changes to Completed. Full data verification does not support resumable verification.
  Click Pause to the right of Actions. In the Note message, click OK.
- Restart data verification
  Note
  You can restart full data verification only when the value of the Status parameter is Completed. After full data verification is restarted, DTS verifies the existing data in the source and destination databases
  You can restart incremental data verification only when the value of the Status parameter is Pausing or Completed.
  Click Restart to the right of Actions. In the Note message, click OK.
- Stop data verification
  Note
  You can stop only incremental data verification. After incremental data verification is stopped, the value of the Status parameter changes to Completed.
  Click Stopped to the right of Actions. In the Note message, click OK.
- Delete data verification
  Important
  A data verification task cannot be recovered after it is deleted. You must configure another data verification task.
  Click Delete to the right of Actions. In the Note message, click OK.

Related API operations

Operation	Description
DescribeDataCheckTableDiffDetails	Queries the information about inconsistent data detected in a table in a data verification task.
DescribeDataCheckReportUrl	Queries the download URL of a data verification report.
DescribeDataCheckTableDetails	Queries the information about a full or incremental data verification task.

FAQ

Why does not full data verification or incremental data verification start?
The cause varies based on whether the task contains the incremental data synchronization or migration stage.
- For the tasks that does not contain the incremental data synchronization or migration stage:
  Full data verification starts after full data is written to the destination database.
- For the tasks that contain the incremental data synchronization or migration stage:
  Note
  Full data verification and incremental data verification do not affect each other.
  - If incremental data migration or synchronization is a single task, data verification starts when incremental data is written to the destination database without latency for the first time.
  - If incremental data migration or synchronization consists of multiple subtasks, data verification starts when the latency of all subtasks is less than 2 seconds. For example, incremental data migration between MongoDB databases consists of multiple subtasks.
Why is the result of incremental data verification empty?
Incremental data verification only records information about databases and tables that contain inconsistent data. DTS performs incremental data verification after incremental data is synchronized or migrated from the source database to the destination database. If no inconsistent data is detected, the result is empty.
Why is the offset in the incremental verification module not updated?
The Current Offset in the incremental verification module is the time at which the latest incremental data verification is performed. If no new incremental data is generated in the source database, the Current Offset is not updated, or no offset information exists.
Why is no inconsistent data detected during incremental data verification after incremental data is written to the destination database?
Incremental data verification checks the data consistency between the source and destination databases based on the source database. Inconsistent data is detected only if the incremental data that is generated in the source database is not written to the destination database or the written data is inconsistent with the source data.