Configuring Cold Tables

1. Log in to the TaurusDB console.
2. Click in the upper left corner and select a region.
3. On the Instances page, click the instance name.
4. In the navigation pane, click Cold and Hot Data Separation.
5. Click on the right of Cold and Hot Data Separation. In the displayed dialog box, click OK.
   Figure 1 Enabling cold and hot data separation
   

6. On the Cold Tables tab, click Create Cold Table.
   Figure 2 Creating a cold table
   

7. In the search bar of the Create Cold Table dialog box, enter the name of the database, table, or partition that contains the data to be archived as cold data. You can search by database name, database name + table name, or database name + table name + partition name.
8. Select the tables or partitions whose data you want to archive as cold data. As prompted, enter YES and click OK.
   Figure 3 Selecting tables for archiving
   

9. After the cold table creation task is submitted, you can view it in the Unsubmitted Tasks list. The database automatically dispatches one task every 5 minutes to archive data.
   Figure 4 Unsubmitted tasks
   

   You can also cancel unsubmitted tasks in the list. To cancel an individual task, click Cancel in the Operation column. To cancel multiple tasks, select them and click Batch Cancel.

10. After a task is dispatched, you can view it in the Submitted Tasks list.
    Figure 5 Viewing submitted tasks
    

11. If you need to frequently modify or query a table, you can migrate a single cold table or multiple cold tables back to the instance. Migrating back cold tables takes a relatively long time, so you are advised to perform this operation during off-peak hours.
    • Migrate back a single cold table: In the cold table list, click Migrate Back. After confirming that the task details are correct, click OK to migrate the cold table back to the instance.
      Figure 6 Migrating back a single cold table
      

    • Migrate back cold tables in batches: Select one or more cold tables and click Batch Recall. After confirming that the task details are correct, click OK to migrate the selected cold tables back to the instance.
      Figure 7 Migrating back cold tables in batches
      

12. Check that the storage space has been released (monitoring data may be delayed).

    

When configuring a cold table using SQL statements, you need to use DAS or a client (such as the mysql client) to connect to your TaurusDB instance and then run the corresponding SQL statements. The following procedure uses DAS as an example.

1. Log in to the TaurusDB console.
2. Click in the upper left corner and select a region.
3. On the Instances page, click the instance name.
4. In the navigation pane, click Cold and Hot Data Separation.
5. Click on the right of Cold and Hot Data Separation. In the displayed dialog box, click OK.
   Figure 8 Enabling cold and hot data separation
   

6. On the Basic Information page, click Log In in the upper right corner.

   Alternatively, return to the Instances page, locate the instance, and click Log In in the Operation column.

   Figure 9 Logging in to an instance
   

7. On the displayed page, enter the username and password and click Test Connection. After the connection is successful, click Log In.
   Figure 10 Login page
   

8. Choose SQL Operations > SQL Window.
   Figure 11 SQL Operations
   

9. Configure a cold table using SQL statements.
   • Creating a cold table

     CALL dbms_schs.make_io_transfer("start", "database_name", "table_name", "partition_name", "", "obs");

     Example:

     CALL dbms_schs.make_io_transfer("start", "test", "table1", "", "", "obs");

     Figure 12 Creating a cold table
     

10. Query the archiving or migration status.

    CALL dbms_schs.show_io_transfer("database_name", "table_name", "partition_name");

    Example:

    CALL dbms_schs.show_io_transfer("test", "table1", "");

    Figure 13 Querying the archiving or migration status
    

11. (Optional) Query all cold tables on an instance as user root.

    The stored procedure sys.schs_show_all requires that the kernel version of your TaurusDB instance be 2.0.60.241200 or later. If the version is older, upgrade it first. For details about how to check the kernel version, see How Can I Check the Version of a TaurusDB Instance?

    CALL sys.schs_show_all( "database_name", "table_name", "partition_name");

    Examples:

    • Querying all cold tables on an instance

      CALL sys.schs_show_all( "", "", "");

    • Querying all cold partitions or cold tables whose database name is test

      CALL sys.schs_show_all( "test", "", "");

    • Querying cold partitions or cold tables whose database name is test and table name is table1

      CALL sys.schs_show_all( "test", "table1", "");

12. Migrate back a cold table.

    CALL dbms_schs.make_io_transfer("start", "database_name", "table_name", "partition_name", "obs", "");

    Example:

    CALL dbms_schs.make_io_transfer("start", "test", "table1", "", "obs", "");

    Figure 14 Migrating back a cold table