There are many ways for a DBA to increase performance and you may want to use some of them in your code.
For example, you may want to list all the indexes that have been created on a table in MySQL. Using the following command, you will be able to list down all the indexes that are available for the table.
SHOW INDEX FROM `database_name`.`TABLE_NAME`;
This command will list all the indexes that are available and the column(s) that have been used for index, along with the index type. Try it for yourself!