Incorrect Results When Using an In-Line View and User Function in 10g

Question

My developers are complaining of incorrect Select statement results when using an in-line view along with a user defined function. Below is the statement:
select test_f(wo1)
from
(SELECT a.WORK_ORDER_NBR, b.work_order_nbr wo1/*, facility_f(A.FACILITY),
A.PLANNER, A.WO_STATUS, mil_date(A.WO_STATUS_DATE)*, A.WORK_ORDER_TYPE,
A.WO_DESCRIPTION
FROM TIDWOWRK A, TIDWOTSK B
WHERE B.WORK_ORDER_NBR(+) = A.WORK_ORDER_NBR))
where wo1 is null;
Test_f() is a user defined function and the above query returns thousands of rows. It should return 308 rows. It is apparent that the target database is not evaluating the "where wo1 is null;" clause.
select to_char(wo1)
from
(SELECT a.WORK_ORDER_NBR, b.work_order_nbr wo1/*, facility_f(A.FACILITY),
A.PLANNER, A.WO_STATUS, mil_date(A.WO_STATUS_DATE)*, A.WORK_ORDER_TYPE,
A.WO_DESCRIPTION
FROM TIDWOWRK A, TIDWOTSK B
WHERE B.WORK_ORDER_NBR(+) = A.WORK_ORDER_NBR))
where wo1 is null;
In the above query return 308 rows. The user function was replaced by an Oracle function. The Where clause is now evaluated correctly.
The query is executed from an Oracle 10g R2 database and retrieves data from a 9.2.0.6 database.
I've seen a little information on Metalink. It appears that there was some trouble in 9i, but were fixed in a 9.2.0.6 patch. I don't see any information about a 10.2.0.2 database.
Anyone have any experiences or a successful solution. I suspect that I will need to report this to Oracle and wait for a patch.
Thanks,
John

Answer 1

I can only think of two reasons for this behaviour:
1) You are executing these two queries from two different users and there is some policy on the table.
2) The function doesn't do an upper, but returns null a lot of times, even when the input is a not null value, like this:
SQL> create table tidwowrk
  2  as
  3  select 1 id, 'A' work_order_nbr, 'DST' facility from dual union all
  4  select 2, null, 'TRN' from dual union all
  5  select 3, 'C', 'DST' from dual
  6  /
Tabel is aangemaakt.
SQL> create table tidwotsk
  2  as
  3  select 'A' work_order_nbr from dual union all
  4  select 'B' from dual
  5  /
Tabel is aangemaakt.
SQL> create or replace function test_f (a in varchar2) return varchar2
  2  is
  3  begin
  4    return case a when 'A' then null else a end;
  5  end;
  6  /
Functie is aangemaakt.
SQL> select count(*)
  2    from ( SELECT a.WORK_ORDER_NBR
  3                , test_f(b.work_order_nbr) wo1
  4             FROM TIDWOWRK A
  5                , TIDWOTSK B
  6            WHERE B.WORK_ORDER_NBR(+) = A.WORK_ORDER_NBR
  7              and a.facility in ('DST', 'TRN', 'SUB')
  8         )
  9   where wo1 is null
10  /
                              COUNT(*)
                                     3
1 rij is geselecteerd.
SQL> select count(*)
  2    from ( SELECT a.WORK_ORDER_NBR
  3                , to_char(b.work_order_nbr) wo1
  4             FROM TIDWOWRK A, TIDWOTSK B
  5            WHERE B.WORK_ORDER_NBR(+) = A.WORK_ORDER_NBR
  6              and a.facility in ('DST', 'TRN', 'SUB')
  7         )
  8   where wo1 is null
  9  /
                              COUNT(*)
                                     2
1 rij is geselecteerd.Regards,
Rob.