Fastest way to get MYSQL random rows

Question

Possible Duplicate:
MySQL select 10 random rows from 600K rows fast
Selecting random rows with MySQL

MY Database has 4 Coloums NAME ID Email sex with 500k rows.

select * from table where sex='m';

I want to get 50 random rows where sex='M'; Which is the fastest method

Answer 1

select * from table where sex='m'
ORDER BY RAND()
LIMIT 50