MySQL : Storing business logic in table [closed]

Question

I have a table named test :

create table demo (name varchar(10), mark1 int, mark2 int);

I need the total of mark1 and mark2 for each row many times.

select name, (mark1 + mark2) as total from demo;

Which I am told is not efficient. I am not allowed to add a new total column in the table.

Can I store such business logic in Index?

I created a view

CREATE VIEW view_total AS SELECT name, (mark1 + mark2) as 'total' from demo;

I populated the demo table with:

DELIMITER $$
CREATE PROCEDURE InsertRand(IN NumRows INT)
    BEGIN
        DECLARE i INT;
        SET i = 1;
        START TRANSACTION;
        WHILE i <= NumRows DO
            INSERT INTO demo VALUES (i,i+1,i+2);
            SET i = i + 1;
        END WHILE;
        COMMIT;
    END$$
DELIMITER ;

CALL InsertRand(100000);

The execution time of

select sum(mark1 + mark2) from view_total;

and

select sum(total) from demo;

is same, 10 ms. So I have not gained any benefit of view. I tried to create index over the view with :

create index demo_total_view on view_total (name, total);

which failed with error :

ERROR 1347 (HY000): 'test.view_total' is not BASE TABLE

Any pointer about how do I prevent the redundant action of totaling the columns?