Need suggestions on writing a better IF condition

Question

Hi,
I have a cursor which returns around 15000 rows. I am processing around these records in a cursor FOR loop based on a condition. The condition ( cursor_variable.customer_id IS NULL AND cursor_variable.class = 'A' ) will evaluate to FALSE 99% of the time. Considering this, which of the following will be the better approach?
Case-I
FOR cursor_variable IN cursor
LOOP
IF ( cursor_variable.customer_id IS NULL AND cursor_variable.class = 'A' ) THEN
<do nothing>
ELSE
<do stuff>
END IF;
END LOOPCase-II
FOR cursor_variable IN cursor
LOOP
IF NOT ( cursor_variable.customer_id IS NULL AND cursor_variable.class = 'A' ) THEN
<do stuff>
END IF;
END LOOPNote: I have a 11g database on Solaris
Regards,
Sujoy

Answer 1

Hi,
Blu and Billy, thanks for you invaluable insights.
I understand that doing everything in SQL would be the best choice considering, among others, performance and scalability. However, the "stuff" inside the LOOP seems a little complex to me. I have included the pseudo-code below:
LOOP
select column_a
  from multiple tables
where join conditions include results from cursor;
--This section will return a bunch of values (set A and set B, for example)
if column_a = 'A' and cursor_variable.value = 'B' then
  --return values from multiple columns(set A)
  select multiple columns
    from multiple tables
   where join conditions include results from cursor;
  select column_b
   from multiple tables
  where join conditions include results from cursor;
  --return values from multiple columns(set B)
  if column_b = 'C' then
      select multiple columns
       from multiple tables
      where join conditions include results from cursor;
  end if;
  --return values from multiple columns(set B)
  if column_b = 'D' then
    select column_c  
     from multiple tables
    where join conditions include results from cursor;
    if column_c = 'E' then
      select multiple columns   
       from multiple tables
      where join conditions include results from cursor;
    end if; 
    if column_c = 'F' then
      select multiple columns
       from multiple tables
      where join conditions include results from cursor;
    end if;
    if column_c = 'G' then
      call a procedure with input parameters to fetch values;
      --using a procedure since there is some complex logic involved and it can be reused
      --in other sections of the package
    end if;
  end if; 
end if; 
Processing similar to what is done in the IF section above is repeated throughout the package to obtain set C, set D... set N etc
insert SET A,B,C,D...N into a single row spread across into tables A, B and C
--having multiple tables is a business requirement
END LOOPRefractoring the code entirely to SQL would definitley be the right way to go, but I am not sure we have the time to do and test that. In the meantime can you please give your suggestion regarding the original question?
Regards,
Sujoy