How to delete permalink/reference of a deleted page/post from wordpress db?

I am sure this problem is very common but a quick googling didn't g开发者_JS百科et me any relevant results. Is there a way to remove it, db query maybe? Or is there an existing plugin that does this?

http://yourdomain/wp-admin/edit.php?post_status=trash&post_type=post

Click "Empty Trash".

If you need more than this, tell me and I'll write you an SQL query. That said, this removes the entry from the database.