Question

I am trying to use MySQL benchmark to test some queries. But, I am running to an error.

SELECT benchmark (10000, (select title from user));

and in return I get this error;

ERROR 1242 (21000): Subquery returns more than 1 row

Does anyone know how to benchmark a query?

Thanks

Answer 1

select title from user

This returns multiple rows, which won’t work.

Refer to this link:
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_benchmark

The expression you pass must return a scalar result.

You need to change the query such that it returns a single row:
ex:

select title from user where user_name = 'some_user'