CTAS blowing my temp space.....

[jmodic]

I want to populate TAB1 with plan_date from p.
If the outer join returns NULL, then NULL is inserted in the new column. If NOT NULL, i.e., a row exists in p. that is not null, then populate the new column with the not null value from p.

CREATE TABLE TAB1 AS 
select t.*, CASE WHEN p.plan_date is NULL THEN null ELSE p.plan_date END plan_date
from   w_card_transaction t, tmp_df_plans p
where  t.account_org = p.account_org(+) ....

So, what's wrong with plain and simple:

CREATE TABLE TAB1 AS 
select t.*, p.plan_date
from   w_card_transaction t, tmp_df_plans p
where  t.account_org = p.account_org(+) ....

Where is the difference?