Hello people,
I need some understanding on these 2 questions.

Question 1:
Assuming the only column indexed in this query below is
emp_id. Should I leave it unchanged or I need
to create an index on SERVICE and the STATUS
column

select emp_name, order_num from emp_table
WHERE
emp_id = '112dd2' AND
service = 'running' AND
status != 'A';

NOTE: Status has a check constraint and it can be to be only A or B?

Question2:
If create an index on the status coulmn
and I have status != in my where clause, would the index be used or not