SQL code copied to buffer

Task

Using a covering index

The actor table has an index idx_actor_last_name on the last_name column. Which of the following queries can use this index as covering index?

select last_name, count(*) from actor group by last_name;

select last_name, last_update from actor order by last_name desc;

select last_name from actor order by last_update;

select distinct last_name from actor;

Mark all correct answers and click the "Check!" button

Get hint

Hi! Could we please enable some services and cookies to improve your experience and our website?

Privacy & Cookie Policy.