# SQL Tuning

#### Procedure

1. On the top menu bar, choose Intelligent O&M > SQL Tuning.
2. In the displayed dialog box, select an instance and click OK.
3. On the SQL Tuning page, click Add SQL Performance Tuning. In the displayed dialog box, enter the SQL statements to be diagnosed and click OK.
4. Click View Details in the Operation column to view tuning details.
5. Under Tuned SQL List, click View Tuning Result Detail in the Operation column to view tuning details.

   - The SQL tuning function obtains the table structure and data distribution information (non-original). The obtained data is only for logic diagnosis, but not stored on the DAS server.
   - Obtaining table structure and data distribution information may add additional loads to the DB instance, but has little impact on its performance.
   - Only the SQL diagnosis history is stored on the DAS server. You can delete it from the server permanently.

Parent topic: Intelligent O&M