Hi Bob & Jill,
 
I understand that having data in columns that contains ' ' can result
in problems if you are assuming that those columns are to contain
something other than ' ' or be NULL.
 
I can change the control files that are used to load the flat files
to set the value of a column to NULL if column in that flat file
is all blanks.  Currently there are about 50 control files.
12 of these are used for ASDSFXYZ data.  These ASDSFXYZ control files
deal with over 400 columns.  It is possible, although unlikely,
a bug may result if I where to add "NULLIF blanks" clause to all
of the columns that are not already being modified by the control files.
Also correcting the control files would not solve this problem for
data that is already loaded or data that will be loaded into the
database in some other manner.  To correct existing records we would
have to:
 
        1) identify all the columns that have ' ' vs. NULL problem
        2) make sure that all update triggers enabled on the tables
           the offending columns are disabled
        3) create backups.
        4) update the records.
        5) test
 
Another point is, what happens to a piece of code that is assuming that
' ' means something?  I know that this is probably unlikely for
a system the size of DOA2000, but this is something one should think about
and test for.  In other words, we could fix the problem in the software
unit that does not handle the ' ' vs. NULL issue very well and just test it.
Or we could do our best to remove the chance of the ' ' vs. NULL problem
ever occurring anywhere in the DOA2000 system and test the whole system.
 
Anonymous Monk