Shadow table synchronization

Background information

The shadow table synchronization feature in OceanBase Developer Center (ODC) automatically creates a shadow table in the current database based on the schema of a source table. The shadow table name is generated by adding a prefix or suffix to the source table name. This is useful for scenarios such as end-to-end stress testing.

This document describes how to create and view shadow table sync tasks in ODC.

Create a shadow table sync task

Example: In the mysql410 data source, create the shadow table employee_t in the odc_test database.

Item	Example Value
Data Source	mysql4.2.0
Database Name	odc_test
Source Table Name	employee
Shadow Table Name	employee_t

1. In the SQL development window, on the Ticket tab, click Shadow Table Sync > Create Shadow Table Sync Task.

2. In the Create Shadow Table Sync Task panel, specify the following information.

   1. Select objects.

      Item	Description
      Database	Select the database where you want to create the shadow table. The name of the current data source is also displayed.
      Sync Scope	Select the tables to sync: Partial Tables: Creates shadow tables for selected tables in the current database. To select all source tables, select the checkbox to the left of the search box. All Tables: Creates shadow tables for all tables from the source database in the current database.
      Shadow Table Name	Create a shadow table name using the format Prefix + `Source Table Name` or `Source Table Name` + Suffix. The prefix and suffix are customizable.
      Sync Objects	If you choose to sync partial tables, select the source tables in the Sync Objects section.

   2. Click **Next** to analyze the shadow table schema.

      Item	Description
      Tables to Sync	On the Tables to Sync tab, the source table name, shadow table name, and analysis result are displayed. Click View to see the source table schema, shadow table schema, and schema evolution SQL statement. Click Skip to exclude the shadow table from synchronization.
      Tables Not to Sync	On the Tables Not to Sync tab, the source table name, shadow table name, and analysis result are displayed. Click Cancel Skip to include the shadow table in the synchronization. Note Tables that you choose to skip are displayed on the **Tables Not to Sync** tab. If a shadow table with the same name already exists and its schema is identical to the source table, the schema sync for that table is skipped automatically.
      SQL Preview	Displays the SQL statements for syncing the table schemas.
      Task Settings	Select an Execution Method for after the task is approved. Sync Immediately: Executes the sync task immediately. Scheduled Sync: Executes the sync task at a scheduled time. Select a method for Task Error Handling. Stop Task: If an error occurs during execution, the task stops and does not execute subsequent SQL scripts. Ignore Errors and Continue: If an error occurs during execution, the task skips the failed SQL script and continues to execute the remaining SQL scripts.
      Description	Describe the business background of the project, such as the purpose and expected goals of the change.

3. After you specify the information, click the Submit button in the lower-right corner of the panel to create the shadow table sync task.

4. After the task is created, the Task Hub panel appears automatically. In the Task Hub, you can view the task's approval status and other information.

View a shadow table sync task

Task information

1. In the Task Hub, find the shadow table sync task in the list and click the View button in the Operations column.

2. In the task details panel that appears, click the Task Information tab to view basic information and settings for the task.

3. In the lower-right corner of the panel, click Run Again to restart the task.

Task flow

1. In the task details panel, click the Task Flow tab to view information such as Task Submission Status, Approval Status, Execution Status, and Completion Result.

2. In the lower-right corner of the panel, click Run Again to restart the task.

Task logs

1. In the task details panel, click the Task Logs tab to view all logs and alert logs for the task.

   Item	Description
   All Logs	The **All Logs** section displays all log information for the task, including INFO, ERROR, and WARN logs. Use the Find, Download, and Copy buttons to search for information or to download or copy all logs.
   Alert Logs	The **Alert Logs** section displays only the ERROR and WARN logs for the task. If a task fails, you can check the alert logs for error messages. Use the Find, Download, and Copy buttons to search for information or to download or copy the alert logs.

2. Click Run Again to restart the task.

References

• SQL editing and execution

• PL compilation and debugging

• Result editing and export

• Execution analysis

• Test data generation

• Lock-free schema evolution

• Partition management

• Scheduled SQL tasks