Identify and tune the top SQLs is a very important way to improve your system's performance. To get the top SQLs, click "Top SQL" button or press F6. Your top SQLs will be listed as below.
Select a SQL, the SQL text will be shown in the left side.
You can change the SQL number to be shown or change the time slot to get the history top SQLs.
If you want to get the top SQL with special wait class/event, you can choose one of wait classes, or further choose one of wait events under the selected wait class.
Choose one of the top SQLs, then click "OK", you will get the details of the selected SQL, and then analyze and tune it. Further information of SQL details, please refert to "Show SQL details".