well, I don't want to start a religious thread here, but I think it is a problem that Oracle treats empty strings as nulls. an empty string is a string, allbeit a short one (just like an empty set is a set, though a small one) and thus has a datatype. a null is a marker, not a value, and has no datatype. therefore, there is (or should be) an important difference between empty strings and nulls.
Yup, religious for sure. But I'll offer one contribution to the empty vs NULL string, one which is particularly close to those of us who have to process long URL's as results of searches in google, inktomi, yahoo, etcetc:
The dreaded "%00".
Which wreaks havoc with string lengths and should be *BANNED* from ALL URLs in the whole wide world! (rant/) Particularly vicious for Pro*C/C++ interfaces if it happens to be right at the start of the URL. Particularly since the "http://" can be stripped off to save space. Nothing more unsettling than to find truncated or just plain missing URLs when you have to send them upstream for further processing and/or tallying, and you counted them all fine at the input.
And no, DAMHIKT!...
-- Cheers Nuno Souto in sunny Sydney, Australia dbvision@xxxxxxxxxxxx -- http://www.freelists.org/webpage/oracle-l