Hi All

I was wondering if anybody knew if 'IN' performs a implicit distinct?
For instance say if i had the query below:

select stat from orders where account_id in (select distinct account_id
from accounts)

Do i need to perform a distinct lookup of the account_id ??? Is this
just a duplicate - which would require an additional sort?

I have constructed a benchmark with the same value repeated in the IN
caluse and I see no difference in response time / CPU time

Test 1
 select count(*) from accounts where account_id in ('15')

Test 2
 select count(*) from accounts where account_id in
('15','15','15','15','15')

Test 3
 select count(*) from accounts where account_id in
 ('15','15','15','15','15','15','15','15','15','15')

Test 4
 select count(*) from accounts where account_id in
 ('15','15','15','15','15','15','15','15','15','15',
  '15','15','15','15','15','15','15','15','15','15',

  '15','15','15','15','15','15','15','15','15','15',

  '15','15','15','15','15','15','15','15','15','15',

  '15','15','15','15','15','15','15','15','15','15')

Bob