How to get a Hash Anti-Join to take?

Im using the Guy Harrison tuning book and he says the hash anti-join is the fastest. What am I doing wrong? Im doing a nested loop index lookup?

This is what I Do:

Alter Session Set always_anti_join = HASH

SELECT 1
  FROM TAB1
  WHERE COL1 NOT IN
(SELECT /*+ HASH_AJ */ to_char(col2)

   from tab2

Dont have the plan table in front of me. Its just a nested loop join with Index lookups. Any idea why? Received on Fri May 02 2003 - 13:19:10 CDT