Shortest Query to Combine Count and Unique (Oracle)

Question

I have the following query which works for me:

select count(*)
from (
   select UNIQUE col1, col2, col3
   from my_table
   where cond1 = 'A'
   and cond2 = 'B'
   and cond3 = 'C'
)

Is it possible to write this without the nested query?

Answer 1

Not that I recommend it, but:

select count(distinct ora_hash(col1)||'|'||ora_hash(col2)||'|'||ora_hash(col3))
from my_table
where cond1 = 'A'
and cond2 = 'B'
and cond3 = 'C'

A nested query seems like "the right answer" to me.