/* Auto Clear WordPress Thrash/ Bin */
define('EMPTY_TRASH_DAYS', 10 ); Thrash increases the size of database. You can manually delete the thrash to keep the database tables light. However, instead of manually deleting thrash, you can automate the process by adding the above code to your wp-config.php in the public_html folder.
This code will clear the thrash every 10 days. You can change the number of days after which the auto delete task is to be performed.