mysql - Optimizing the sql with subquery with group by -

could me optimize query? have table huge data. me optimize without using sub query?

select user_id, scheduled_on_date       (select user_id, scheduled_on_date      `calls`      order scheduled_on_date desc) cinner   group user_id 

output expected is: need rows of users last scheduled_date call.

you can rewrite query follows

select c.user_id, c.scheduled_on_date ,other_fields_max_per_group `calls` c join (select user_id, max(scheduled_on_date) scheduled_on_date      `calls`       group user_id) cc on(c.user_id =cc.user_id , c.scheduled_on_date =cc.scheduled_on_date) 

add compound index

alter table calls add index `test` (user_id ,scheduled_on_date ) 

if there want greatest date , user id can use

select user_id, max(scheduled_on_date) scheduled_on_date `calls` group user_id