Thanx to Witold and Prakash for suggesting NULLIF and DEFAULTIF.
Unfortunately, it looks like both of those do basically the opposite of
what I'm trying to accomplish. Essentially, I want to prevent
sql*loader from ever inserting NULL in a column (which may not be
numeric), substituting whatever value is appropriate for the given
application instead. Something like using "nvl(:field,'unknown')" in
the field specification of the control file for conventional path loads.
As far as I can see, there's no way to do this within sql*loader
itself. So the choices would be to run a cleanup just after the load
(which may or may not negate the speed benefits of using direct path),
or to somehow pre-process the data file to fill in the missing values
(perhaps an awk or perl script). Of course, if I'm missing something
obvious please let me know... the sql*loader documentation seems
designed to confuse. (-:
Cheers!
